lifetime insanity

Summary
--

Fixes #19640. I'm not sure these are the exact fixes we really want, but
I
reproduced the issue in a 32-bit Docker container and tracked down the
causes,
so I figured I'd open a PR.

As I commented on the issue, the `goto_references` test depends on the
iteration
order of the files in an `FxHashSet` in `Indexed`. In this case, we can
just
sort the output in test code.

Similarly, the tuple case depended on the order of overloads inserted in
an
`FxHashMap`. `FxIndexMap` seemed like a convenient drop-in replacement,
but I
don't know if that will have other detrimental effects. I did have to
change the
assertion for the tuple test, but I think it should now be stable across
architectures.

Test Plan
--

Running the tests in the aforementioned Docker container

CHANGELOG.md

@@ -1,5 +1,35 @@
 # Changelog
 
+## 0.12.7
+
+This is a follow-up release to 0.12.6. Because of an issue in the package metadata, 0.12.6 failed to publish fully to PyPI and has been yanked. Similarly, there is no GitHub release or Git tag for 0.12.6. The contents of the 0.12.7 release are identical to 0.12.6, except for the updated metadata.
+
+## 0.12.6
+
+### Preview features
+
+- \[`flake8-commas`\] Add support for trailing comma checks in type parameter lists (`COM812`, `COM819`) ([#19390](https://github.com/astral-sh/ruff/pull/19390))
+- \[`pylint`\] Implement auto-fix for `missing-maxsplit-arg` (`PLC0207`) ([#19387](https://github.com/astral-sh/ruff/pull/19387))
+- \[`ruff`\] Offer fixes for `RUF039` in more cases ([#19065](https://github.com/astral-sh/ruff/pull/19065))
+
+### Bug fixes
+
+- Support `.pyi` files in ruff analyze graph ([#19611](https://github.com/astral-sh/ruff/pull/19611))
+- \[`flake8-pyi`\] Preserve inline comment in ellipsis removal (`PYI013`) ([#19399](https://github.com/astral-sh/ruff/pull/19399))
+- \[`perflint`\] Ignore rule if target is `global` or `nonlocal` (`PERF401`) ([#19539](https://github.com/astral-sh/ruff/pull/19539))
+- \[`pyupgrade`\] Fix `UP030` to avoid modifying double curly braces in format strings ([#19378](https://github.com/astral-sh/ruff/pull/19378))
+- \[`refurb`\] Ignore decorated functions for `FURB118` ([#19339](https://github.com/astral-sh/ruff/pull/19339))
+- \[`refurb`\] Mark `int` and `bool` cases for `Decimal.from_float` as safe fixes (`FURB164`) ([#19468](https://github.com/astral-sh/ruff/pull/19468))
+- \[`ruff`\] Fix `RUF033` for named default expressions ([#19115](https://github.com/astral-sh/ruff/pull/19115))
+
+### Rule changes
+
+- \[`flake8-blind-except`\] Change `BLE001` to permit `logging.critical(..., exc_info=True)` ([#19520](https://github.com/astral-sh/ruff/pull/19520))
+
+### Performance
+
+- Add support for specifying minimum dots in detected string imports ([#19538](https://github.com/astral-sh/ruff/pull/19538))
+
 ## 0.12.5
 
 ### Preview features

Cargo.lock

@@ -4,9 +4,9 @@ version = 4
 
 [[package]]
 name = "adler2"
-version = "2.0.0"
+version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "512761e0bb2578dd7380c6baaa0f4ce03e84f95e960231d1dec8bf4d7d6e2627"
+checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
 [[package]]
 name = "aho-corasick"
@@ -77,52 +77,52 @@ checksum = "862ed96ca487e809f1c8e5a8447f6ee2cf102f846893800b20cebdf541fc6bbd"
 
 [[package]]
 name = "anstyle-lossy"
-version = "1.1.3"
+version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "934ff8719effd2023a48cf63e69536c1c3ced9d3895068f6f5cc9a4ff845e59b"
+checksum = "04d3a5dc826f84d0ea11882bb8054ff7f3d482602e11bb181101303a279ea01f"
 dependencies = [
  "anstyle",
 ]
 
 [[package]]
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-version = "0.2.6"
+version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b2d16507662817a6a20a9ea92df6652ee4f94f914589377d69f3b21bc5798a9"
+checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
 dependencies = [
  "utf8parse",
 ]
 
 [[package]]
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-version = "1.1.2"
+version = "1.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "79947af37f4177cfead1110013d678905c37501914fba0efea834c3fe9a8d60c"
+checksum = "6c8bdeb6047d8983be085bab0ba1472e6dc604e7041dbf6fcd5e71523014fae9"
 dependencies = [
  "windows-sys 0.59.0",
 ]
 
 [[package]]
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-version = "0.1.7"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d3607949e9f6de49ea4bafe12f5e4fd73613ebf24795e48587302a8cc0e4bb35"
+checksum = "0a43964079ef399480603125d5afae2b219aceffb77478956e25f17b9bc3435c"
 dependencies = [
- "anstream",
  "anstyle",
  "anstyle-lossy",
+ "anstyle-parse",
  "html-escape",
  "unicode-width 0.2.1",
 ]
 
 [[package]]
 name = "anstyle-wincon"
-version = "3.0.7"
+version = "3.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ca3534e77181a9cc07539ad51f2141fe32f6c3ffd4df76db8ad92346b003ae4e"
+checksum = "403f75924867bb1033c59fbf0797484329750cfbe3c4325cd33127941fabc882"
 dependencies = [
  "anstyle",
- "once_cell",
+ "once_cell_polyfill",
  "windows-sys 0.59.0",
 ]
 
@@ -210,9 +210,9 @@ dependencies = [
 
 [[package]]
 name = "autocfg"
-version = "1.4.0"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "base64"
@@ -301,9 +301,9 @@ dependencies = [
 
 [[package]]
 name = "bumpalo"
-version = "3.17.0"
+version = "3.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1628fb46dfa0b37568d12e5edd512553eccf6a22a78e8bde00bb4aed84d5bdbf"
+checksum = "46c5e41b57b8bba42a04676d81cb89e9ee8e859a1a66f80a5a72e1cb76b34d43"
 
 [[package]]
 name = "byteorder"
@@ -337,18 +337,18 @@ checksum = "37b2a672a2cb129a2e41c10b1224bb368f9f37a2b16b612598138befd7b37eb5"
 
 [[package]]
 name = "castaway"
-version = "0.2.3"
+version = "0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0abae9be0aaf9ea96a3b1b8b1b55c602ca751eba1b1500220cea4ecbafe7c0d5"
+checksum = "dec551ab6e7578819132c713a93c022a05d60159dc86e7a7050223577484c55a"
 dependencies = [
  "rustversion",
 ]
 
 [[package]]
 name = "cc"
-version = "1.2.23"
+version = "1.2.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f4ac86a9e5bc1e2b3449ab9d7d3a6a405e3d1bb28d7b9be8614f55846ae3766"
+checksum = "deec109607ca693028562ed836a5f1c4b8bd77755c4e132fc5ce11b0b6211ae7"
 dependencies = [
  "jobserver",
  "libc",
@@ -357,9 +357,9 @@ dependencies = [
 
 [[package]]
 name = "cfg-if"
-version = "1.0.0"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+checksum = "9555578bc9e57714c812a1f84e4fc5b4d21fcb063490c624de019f7464c91268"
 
 [[package]]
 name = "cfg_aliases"
@@ -408,9 +408,9 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.5.41"
+version = "4.5.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be92d32e80243a54711e5d7ce823c35c41c9d929dc4ab58e1276f625841aadf9"
+checksum = "ed87a9d530bb41a67537289bafcac159cb3ee28460e0a4571123d2a778a6a882"
 dependencies = [
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  "clap_derive",
@@ -418,9 +418,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.5.41"
+version = "4.5.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "707eab41e9622f9139419d573eca0900137718000c517d47da73045f54331c3d"
+checksum = "64f4f3f3c77c94aff3c7e9aac9a2ca1974a5adf392a8bb751e827d6d127ab966"
 dependencies = [
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  "anstyle",
@@ -431,9 +431,9 @@ dependencies = [
 
 [[package]]
 name = "clap_complete"
-version = "4.5.50"
+version = "4.5.55"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c91d3baa3bcd889d60e6ef28874126a0b384fd225ab83aa6d8a801c519194ce1"
+checksum = "a5abde44486daf70c5be8b8f8f1b66c49f86236edf6fa2abadb4d961c4c6229a"
 dependencies = [
  "clap",
 ]
@@ -451,9 +451,9 @@ dependencies = [
 
 [[package]]
 name = "clap_complete_nushell"
-version = "4.5.5"
+version = "4.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c6a8b1593457dfc2fe539002b795710d022dc62a65bf15023f039f9760c7b18a"
+checksum = "0a0c951694691e65bf9d421d597d68416c22de9632e884c28412cb8cd8b73dce"
 dependencies = [
  "clap",
  "clap_complete",
@@ -473,9 +473,9 @@ dependencies = [
 
 [[package]]
 name = "clap_lex"
-version = "0.7.4"
+version = "0.7.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f46ad14479a25103f283c0f10005961cf086d8dc42205bb44c46ac563475dca6"
+checksum = "b94f61472cee1439c0b966b47e3aca9ae07e45d070759512cd390ea2bebc6675"
 
 [[package]]
 name = "clearscreen"
@@ -492,9 +492,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed"
-version = "3.0.2"
+version = "3.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "922018102595f6668cdd09c03f4bff2d951ce2318c6dca4fe11bdcb24b65b2bf"
+checksum = "d29180405ab3b37bb020246ea66bf8ae233708766fd59581ae929feaef10ce91"
 dependencies = [
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  "bincode 1.3.3",
@@ -510,9 +510,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-criterion-compat"
-version = "3.0.2"
+version = "3.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24d8ad82d2383cb74995f58993cbdd2914aed57b2f91f46580310dd81dc3d05a"
+checksum = "2454d874ca820ffd71273565530ad318f413195bbc99dce6c958ca07db362c63"
 dependencies = [
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@@ -521,9 +521,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-criterion-compat-walltime"
-version = "3.0.2"
+version = "3.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61badaa6c452d192a29f8387147888f0ab358553597c3fe9bf8a162ef7c2fa64"
+checksum = "093a9383cdd1a5a0bd1a47cdafb49ae0c6dcd0793c8fb8f79768bab423128c9c"
 dependencies = [
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  "cast",
@@ -546,9 +546,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-divan-compat"
-version = "3.0.2"
+version = "3.0.4"
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-checksum = "3acf1d6fe367c2ff5ff136ca723f678490c3691d59d7f2b83d5e53b7b25ac91e"
+checksum = "e1c73bce1e3f47738bf74a6b58b72a49b4f40c837ce420d8d65a270298592aac"
 dependencies = [
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@@ -557,9 +557,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-divan-compat-macros"
-version = "3.0.2"
+version = "3.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bcfa2013d7bee54a497d0e1410751d5de690fd67a3e9eb728ca049b6a3d16d0b"
+checksum = "ea51dd8add7eba774cc24b4a98324252ac3ec092ccb5f07e52bbe1cb72a6d373"
 dependencies = [
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@@ -571,9 +571,9 @@ dependencies = [
 
 [[package]]
 name = "codspeed-divan-compat-walltime"
-version = "3.0.2"
+version = "3.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e513100fb0e7ba02fb3824546ecd2abfb8f334262f0972225b463aad07f99ff0"
+checksum = "417e9edfc4b0289d4b9b48e62f98c6168d5e30c0e612b2935e394b0dd930fe83"
 dependencies = [
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  "clap",
@@ -586,15 +586,15 @@ dependencies = [
 
 [[package]]
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-version = "1.0.1"
+version = "1.0.2"
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-checksum = "186dce98367766de751c42c4f03970fc60fc012296e706ccbb9d5df9b6c1e271"
+checksum = "26b3f65b8fb8e88ba339f7d23a390fe1b0896217da05e2a66c584c9b29a91df8"
 
 [[package]]
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-version = "1.0.3"
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-checksum = "5b63caa9aa9397e2d9480a9b13673856c78d8ac123288526c37d7839f2a86990"
+checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
 
 [[package]]
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@@ -704,9 +704,9 @@ dependencies = [
 
 [[package]]
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-version = "1.4.2"
+version = "1.5.0"
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-checksum = "a97769d94ddab943e4510d138150169a2758b5ef3eb191a9ee688de3e23ef7b3"
+checksum = "9481c1c90cbf2ac953f07c8d4a58aa3945c425b7185c9154d67a65e4230da511"
 dependencies = [
  "cfg-if",
 ]
@@ -810,9 +810,9 @@ checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
 
 [[package]]
 name = "crunchy"
-version = "0.2.3"
+version = "0.2.4"
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-checksum = "43da5946c66ffcc7745f48db692ffbb10a83bfe0afd96235c5c2a4fb23994929"
+checksum = "460fbee9c2c2f33933d720630a6a0bac33ba7053db5344fac858d4b8952d77d5"
 
 [[package]]
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@@ -1000,9 +1000,9 @@ checksum = "92773504d58c093f6de2459af4af33faa518c13451eb8f2b5698ed3d36e7c813"
 
 [[package]]
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+checksum = "d0881ea181b1df73ff77ffaaf9c7544ecc11e82fba9b5f27b262a3c73a332555"
 
 [[package]]
 name = "either"
@@ -1030,12 +1030,12 @@ checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
 [[package]]
 name = "errno"
-version = "0.3.12"
+version = "0.3.13"
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-checksum = "cea14ef9355e3beab063703aa9dab15afd25f0667c341310c1e5274bb1d0da18"
+checksum = "778e2ac28f6c47af28e4907f13ffd1e1ddbd400980a9abd7c8df189bf578a5ad"
 dependencies = [
  "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -1096,9 +1096,9 @@ dependencies = [
 
 [[package]]
 name = "flate2"
-version = "1.1.1"
+version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7ced92e76e966ca2fd84c8f7aa01a4aea65b0eb6648d72f7c8f3e2764a67fece"
+checksum = "4a3d7db9596fecd151c5f638c0ee5d5bd487b6e0ea232e5dc96d5250f6f94b1d"
 dependencies = [
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@@ -1184,11 +1184,11 @@ dependencies = [
 
 [[package]]
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-version = "0.2.21"
+version = "0.2.23"
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+checksum = "cba6ae63eb948698e300f645f87c70f76630d505f23b8907cf1e193ee85048c1"
 dependencies = [
- "unicode-width 0.1.14",
+ "unicode-width 0.2.1",
 ]
 
 [[package]]
@@ -1199,7 +1199,7 @@ checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi 0.11.0+wasi-snapshot-preview1",
+ "wasi 0.11.1+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -1290,15 +1290,9 @@ checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
 name = "hermit-abi"
-version = "0.3.9"
+version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
-
-[[package]]
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-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f154ce46856750ed433c8649605bf7ed2de3bc35fd9d2a9f30cddd873c80cb08"
+checksum = "fc0fef456e4baa96da950455cd02c081ca953b141298e41db3fc7e36b1da849c"
 
 [[package]]
 name = "home"
@@ -1391,9 +1385,9 @@ checksum = "00210d6893afc98edb752b664b8890f0ef174c8adbb8d0be9710fa66fbbf72d3"
 
 [[package]]
 name = "icu_properties"
-version = "2.0.0"
+version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2549ca8c7241c82f59c80ba2a6f415d931c5b58d24fb8412caa1a1f02c49139a"
+checksum = "016c619c1eeb94efb86809b015c58f479963de65bdb6253345c1a1276f22e32b"
 dependencies = [
  "displaydoc",
  "icu_collections",
@@ -1407,9 +1401,9 @@ dependencies = [
 
 [[package]]
 name = "icu_properties_data"
-version = "2.0.0"
+version = "2.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8197e866e47b68f8f7d95249e172903bec06004b18b2937f1095d40a0c57de04"
+checksum = "298459143998310acd25ffe6810ed544932242d3f07083eee1084d83a71bd632"
 
 [[package]]
 name = "icu_provider"
@@ -1621,7 +1615,7 @@ version = "0.4.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e04d7f318608d35d4b61ddd75cbdaee86b023ebe2bd5a66ee0915f0bf93095a9"
 dependencies = [
- "hermit-abi 0.5.1",
+ "hermit-abi",
  "libc",
  "windows-sys 0.59.0",
 ]
@@ -1811,9 +1805,9 @@ dependencies = [
 
 [[package]]
 name = "libredox"
-version = "0.1.3"
+version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c0ff37bd590ca25063e35af745c343cb7a0271906fb7b37e4813e8f79f00268d"
+checksum = "360e552c93fa0e8152ab463bc4c4837fce76a225df11dfaeea66c313de5e61f7"
 dependencies = [
  "bitflags 2.9.1",
  "libc",
@@ -1980,23 +1974,23 @@ checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
 
 [[package]]
 name = "miniz_oxide"
-version = "0.8.8"
+version = "0.8.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3be647b768db090acb35d5ec5db2b0e1f1de11133ca123b9eacf5137868f892a"
+checksum = "1fa76a2c86f704bdb222d66965fb3d63269ce38518b83cb0575fca855ebb6316"
 dependencies = [
  "adler2",
 ]
 
 [[package]]
 name = "mio"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2886843bf800fba2e3377cff24abf6379b4c4d5c6681eaf9ea5b0d15090450bd"
+checksum = "78bed444cc8a2160f01cbcf811ef18cac863ad68ae8ca62092e8db51d51c761c"
 dependencies = [
  "libc",
  "log",
- "wasi 0.11.0+wasi-snapshot-preview1",
- "windows-sys 0.52.0",
+ "wasi 0.11.1+wasi-snapshot-preview1",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -2007,9 +2001,9 @@ checksum = "308d96db8debc727c3fd9744aac51751243420e46edf401010908da7f8d5e57c"
 
 [[package]]
 name = "newtype-uuid"
-version = "1.2.1"
+version = "1.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee3224f0e8be7c2a1ebc77ef9c3eecb90f55c6594399ee825de964526b3c9056"
+checksum = "a17d82edb1c8a6c20c238747ae7aae9181133e766bc92cd2556fdd764407d0d1"
 dependencies = [
  "uuid",
 ]
@@ -2099,11 +2093,11 @@ dependencies = [
 
 [[package]]
 name = "num_cpus"
-version = "1.16.0"
+version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
+checksum = "91df4bbde75afed763b708b7eee1e8e7651e02d97f6d5dd763e89367e957b23b"
 dependencies = [
- "hermit-abi 0.3.9",
+ "hermit-abi",
  "libc",
 ]
 
@@ -2113,6 +2107,12 @@ version = "1.21.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
+[[package]]
+name = "once_cell_polyfill"
+version = "1.70.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4895175b425cb1f87721b59f0f286c2092bd4af812243672510e1ac53e2e0ad"
+
 [[package]]
 name = "oorandom"
 version = "11.1.5"
@@ -2137,9 +2137,9 @@ dependencies = [
 
 [[package]]
 name = "os_pipe"
-version = "1.2.1"
+version = "1.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ffd2b0a5634335b135d5728d84c5e0fd726954b87111f7506a61c502280d982"
+checksum = "db335f4760b14ead6290116f2427bf33a14d4f0617d49f78a246de10c1831224"
 dependencies = [
  "libc",
  "windows-sys 0.59.0",
@@ -2147,9 +2147,9 @@ dependencies = [
 
 [[package]]
 name = "os_str_bytes"
-version = "7.1.0"
+version = "7.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c86e2db86dd008b4c88c77a9bb83d9286bf77204e255bb3fda3b2eebcae66b62"
+checksum = "63eceb7b5d757011a87d08eb2123db15d87fb0c281f65d101ce30a1e96c3ad5c"
 dependencies = [
  "memchr",
 ]
@@ -2162,9 +2162,9 @@ checksum = "b15813163c1d831bf4a13c3610c05c0d03b39feb07f7e09fa234dac9b15aaf39"
 
 [[package]]
 name = "parking_lot"
-version = "0.12.3"
+version = "0.12.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f1bf18183cf54e8d6059647fc3063646a1801cf30896933ec2311622cc4b9a27"
+checksum = "70d58bf43669b5795d1576d0641cfb6fbb2057bf629506267a92807158584a13"
 dependencies = [
  "lock_api",
  "parking_lot_core",
@@ -2172,9 +2172,9 @@ dependencies = [
 
 [[package]]
 name = "parking_lot_core"
-version = "0.9.10"
+version = "0.9.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e401f977ab385c9e4e3ab30627d6f26d00e2c73eef317493c4ec6d468726cf8"
+checksum = "bc838d2a56b5b1a6c25f55575dfc605fabb63bb2365f6c2353ef9159aa69e4a5"
 dependencies = [
  "cfg-if",
  "libc",
@@ -2289,9 +2289,9 @@ checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
 [[package]]
 name = "pest"
-version = "2.8.0"
+version = "2.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "198db74531d58c70a361c42201efde7e2591e976d518caf7662a47dc5720e7b6"
+checksum = "1db05f56d34358a8b1066f67cbb203ee3e7ed2ba674a6263a1d5ec6db2204323"
 dependencies = [
  "memchr",
  "thiserror 2.0.12",
@@ -2300,9 +2300,9 @@ dependencies = [
 
 [[package]]
 name = "pest_derive"
-version = "2.8.0"
+version = "2.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d725d9cfd79e87dccc9341a2ef39d1b6f6353d68c4b33c177febbe1a402c97c5"
+checksum = "bb056d9e8ea77922845ec74a1c4e8fb17e7c218cc4fc11a15c5d25e189aa40bc"
 dependencies = [
  "pest",
  "pest_generator",
@@ -2310,9 +2310,9 @@ dependencies = [
 
 [[package]]
 name = "pest_generator"
-version = "2.8.0"
+version = "2.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db7d01726be8ab66ab32f9df467ae8b1148906685bbe75c82d1e65d7f5b3f841"
+checksum = "87e404e638f781eb3202dc82db6760c8ae8a1eeef7fb3fa8264b2ef280504966"
 dependencies = [
  "pest",
  "pest_meta",
@@ -2323,11 +2323,10 @@ dependencies = [
 
 [[package]]
 name = "pest_meta"
-version = "2.8.0"
+version = "2.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f9f832470494906d1fca5329f8ab5791cc60beb230c74815dff541cbd2b5ca0"
+checksum = "edd1101f170f5903fde0914f899bb503d9ff5271d7ba76bbb70bea63690cc0d5"
 dependencies = [
- "once_cell",
  "pest",
  "sha2",
 ]
@@ -2384,9 +2383,9 @@ checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
 
 [[package]]
 name = "portable-atomic"
-version = "1.11.0"
+version = "1.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "350e9b48cbc6b0e028b0473b114454c6316e57336ee184ceab6e53f72c178b3e"
+checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
 
 [[package]]
 name = "portable-atomic-util"
@@ -2572,9 +2571,9 @@ dependencies = [
 
 [[package]]
 name = "r-efi"
-version = "5.2.0"
+version = "5.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "74765f6d916ee2faa39bc8e68e4f3ed8949b48cccdac59983d287a7cb71ce9c5"
+checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
 
 [[package]]
 name = "radium"
@@ -2663,9 +2662,9 @@ dependencies = [
 
 [[package]]
 name = "redox_syscall"
-version = "0.5.12"
+version = "0.5.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "928fca9cf2aa042393a8325b9ead81d2f0df4cb12e1e24cef072922ccd99c5af"
+checksum = "5407465600fb0548f1442edf71dd20683c6ed326200ace4b1ef0763521bb3b77"
 dependencies = [
  "bitflags 2.9.1",
 ]
@@ -2744,7 +2743,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.12.5"
+version = "0.12.7"
 dependencies = [
  "anyhow",
  "argfile",
@@ -2796,7 +2795,7 @@ dependencies = [
  "test-case",
  "thiserror 2.0.12",
  "tikv-jemallocator",
- "toml 0.9.2",
+ "toml 0.9.4",
  "tracing",
  "walkdir",
  "wild",
@@ -2812,7 +2811,7 @@ dependencies = [
  "ruff_annotate_snippets",
  "serde",
  "snapbox",
- "toml 0.9.2",
+ "toml 0.9.4",
  "tryfn",
  "unicode-width 0.2.1",
 ]
@@ -2891,7 +2890,6 @@ dependencies = [
  "tracing",
  "tracing-subscriber",
  "ty_static",
- "unicode-width 0.2.1",
  "web-time",
  "zip",
 ]
@@ -2929,7 +2927,7 @@ dependencies = [
  "similar",
  "strum",
  "tempfile",
- "toml 0.9.2",
+ "toml 0.9.4",
  "tracing",
  "tracing-indicatif",
  "tracing-subscriber",
@@ -2997,7 +2995,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_linter"
-version = "0.12.5"
+version = "0.12.7"
 dependencies = [
  "aho-corasick",
  "anyhow",
@@ -3050,7 +3048,7 @@ dependencies = [
  "tempfile",
  "test-case",
  "thiserror 2.0.12",
- "toml 0.9.2",
+ "toml 0.9.4",
  "typed-arena",
  "unicode-normalization",
  "unicode-width 0.2.1",
@@ -3300,7 +3298,7 @@ dependencies = [
  "serde_json",
  "shellexpand",
  "thiserror 2.0.12",
- "toml 0.9.2",
+ "toml 0.9.4",
  "tracing",
  "tracing-log",
  "tracing-subscriber",
@@ -3329,7 +3327,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_wasm"
-version = "0.12.5"
+version = "0.12.7"
 dependencies = [
  "console_error_panic_hook",
  "console_log",
@@ -3390,7 +3388,7 @@ dependencies = [
  "shellexpand",
  "strum",
  "tempfile",
- "toml 0.9.2",
+ "toml 0.9.4",
 ]
 
 [[package]]
@@ -3417,22 +3415,22 @@ checksum = "781442f29170c5c93b7185ad559492601acdc71d5bb0706f5868094f45cfcd08"
 
 [[package]]
 name = "rustix"
-version = "1.0.7"
+version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c71e83d6afe7ff64890ec6b71d6a69bb8a610ab78ce364b3352876bb4c801266"
+checksum = "11181fbabf243db407ef8df94a6ce0b2f9a733bd8be4ad02b4eda9602296cac8"
 dependencies = [
  "bitflags 2.9.1",
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.59.0",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
 name = "rustversion"
-version = "1.0.20"
+version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eded382c5f5f786b989652c49544c4877d9f015cc22e145a5ea8ea66c2921cd2"
+checksum = "8a0d197bd2c9dc6e53b84da9556a69ba4cdfab8619eb41a8bd1cc2027a0f6b1d"
 
 [[package]]
 name = "ryu"
@@ -3443,7 +3441,7 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 [[package]]
 name = "salsa"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=dba66f1a37acca014c2402f231ed5b361bd7d8fe#dba66f1a37acca014c2402f231ed5b361bd7d8fe"
+source = "git+https://github.com/salsa-rs/salsa?rev=f3dc2f30f9a250618161e35600a00de7fe744953#f3dc2f30f9a250618161e35600a00de7fe744953"
 dependencies = [
  "boxcar",
  "compact_str",
@@ -3468,12 +3466,12 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=dba66f1a37acca014c2402f231ed5b361bd7d8fe#dba66f1a37acca014c2402f231ed5b361bd7d8fe"
+source = "git+https://github.com/salsa-rs/salsa?rev=f3dc2f30f9a250618161e35600a00de7fe744953#f3dc2f30f9a250618161e35600a00de7fe744953"
 
 [[package]]
 name = "salsa-macros"
 version = "0.23.0"
-source = "git+https://github.com/salsa-rs/salsa?rev=dba66f1a37acca014c2402f231ed5b361bd7d8fe#dba66f1a37acca014c2402f231ed5b361bd7d8fe"
+source = "git+https://github.com/salsa-rs/salsa?rev=f3dc2f30f9a250618161e35600a00de7fe744953#f3dc2f30f9a250618161e35600a00de7fe744953"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3940,12 +3938,11 @@ dependencies = [
 
 [[package]]
 name = "thread_local"
-version = "1.1.8"
+version = "1.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8b9ef9bad013ada3808854ceac7b46812a6465ba368859a37e2100283d2d719c"
+checksum = "f60246a4944f24f6e018aa17cdeffb7818b76356965d03b07d6a9886e8962185"
 dependencies = [
  "cfg-if",
- "once_cell",
 ]
 
 [[package]]
@@ -4026,9 +4023,9 @@ dependencies = [
 
 [[package]]
 name = "toml"
-version = "0.9.2"
+version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed0aee96c12fa71097902e0bb061a5e1ebd766a6636bb605ba401c45c1650eac"
+checksum = "41ae868b5a0f67631c14589f7e250c1ea2c574ee5ba21c6c8dd4b1485705a5a1"
 dependencies = [
  "indexmap",
  "serde",
@@ -4099,9 +4096,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-attributes"
-version = "0.1.28"
+version = "0.1.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "395ae124c09f9e6918a2310af6038fba074bcf474ac352496d5910dd59a2226d"
+checksum = "81383ab64e72a7a8b8e13130c49e3dab29def6d0c7d76a03087b3cf71c5c6903"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4131,9 +4128,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-indicatif"
-version = "0.3.11"
+version = "0.3.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c714cc8fc46db04fcfddbd274c6ef59bebb1b435155984e7c6e89c3ce66f200"
+checksum = "e1983afead46ff13a3c93581e0cec31d20b29efdd22cbdaa8b9f850eccf2c352"
 dependencies = [
  "indicatif",
  "tracing",
@@ -4206,7 +4203,7 @@ dependencies = [
  "ruff_python_trivia",
  "salsa",
  "tempfile",
- "toml 0.9.2",
+ "toml 0.9.4",
  "tracing",
  "tracing-flame",
  "tracing-subscriber",
@@ -4267,7 +4264,7 @@ dependencies = [
  "schemars",
  "serde",
  "thiserror 2.0.12",
- "toml 0.9.2",
+ "toml 0.9.4",
  "tracing",
  "ty_python_semantic",
  "ty_vendored",
@@ -4390,7 +4387,7 @@ dependencies = [
  "smallvec",
  "tempfile",
  "thiserror 2.0.12",
- "toml 0.9.2",
+ "toml 0.9.4",
  "tracing",
  "ty_python_semantic",
  "ty_static",
@@ -4714,9 +4711,9 @@ dependencies = [
 
 [[package]]
 name = "wasi"
-version = "0.11.0+wasi-snapshot-preview1"
+version = "0.11.1+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
 name = "wasi"
@@ -4895,9 +4892,9 @@ checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
 [[package]]
 name = "windows-core"
-version = "0.61.1"
+version = "0.61.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46ec44dc15085cea82cf9c78f85a9114c463a369786585ad2882d1ff0b0acf40"
+checksum = "c0fdd3ddb90610c7638aa2b3a3ab2904fb9e5cdbecc643ddb3647212781c4ae3"
 dependencies = [
  "windows-implement",
  "windows-interface",
@@ -4930,37 +4927,28 @@ dependencies = [
 
 [[package]]
 name = "windows-link"
-version = "0.1.1"
+version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76840935b766e1b0a05c0066835fb9ec80071d4c09a16f6bd5f7e655e3c14c38"
+checksum = "5e6ad25900d524eaabdbbb96d20b4311e1e7ae1699af4fb28c17ae66c80d798a"
 
 [[package]]
 name = "windows-result"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4b895b5356fc36103d0f64dd1e94dfa7ac5633f1c9dd6e80fe9ec4adef69e09d"
+checksum = "56f42bd332cc6c8eac5af113fc0c1fd6a8fd2aa08a0119358686e5160d0586c6"
 dependencies = [
  "windows-link",
 ]
 
 [[package]]
 name = "windows-strings"
-version = "0.4.1"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2a7ab927b2637c19b3dbe0965e75d8f2d30bdd697a1516191cad2ec4df8fb28a"
+checksum = "56e6c93f3a0c3b36176cb1327a4958a0353d5d166c2a35cb268ace15e91d3b57"
 dependencies = [
  "windows-link",
 ]
 
-[[package]]
-name = "windows-sys"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
-dependencies = [
- "windows-targets 0.52.6",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.59.0"
@@ -4976,7 +4964,7 @@ version = "0.60.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
 dependencies = [
- "windows-targets 0.53.2",
+ "windows-targets 0.53.3",
 ]
 
 [[package]]
@@ -4997,10 +4985,11 @@ dependencies = [
 
 [[package]]
 name = "windows-targets"
-version = "0.53.2"
+version = "0.53.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c66f69fcc9ce11da9966ddb31a40968cad001c5bedeb5c2b82ede4253ab48aef"
+checksum = "d5fe6031c4041849d7c496a8ded650796e7b6ecc19df1a431c1a363342e5dc91"
 dependencies = [
+ "windows-link",
  "windows_aarch64_gnullvm 0.53.0",
  "windows_aarch64_msvc 0.53.0",
  "windows_i686_gnu 0.53.0",
@@ -5109,9 +5098,9 @@ checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
 
 [[package]]
 name = "winnow"
-version = "0.7.10"
+version = "0.7.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c06928c8748d81b05c9be96aad92e1b6ff01833332f281e8cfca3be4b35fc9ec"
+checksum = "f3edebf492c8125044983378ecb5766203ad3b4c2f7a922bd7dd207f6d443e95"
 dependencies = [
  "memchr",
 ]
@@ -5178,18 +5167,18 @@ dependencies = [
 
 [[package]]
 name = "zerocopy"
-version = "0.8.25"
+version = "0.8.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1702d9583232ddb9174e01bb7c15a2ab8fb1bc6f227aa1233858c351a3ba0cb"
+checksum = "1039dd0d3c310cf05de012d8a39ff557cb0d23087fd44cad61df08fc31907a2f"
 dependencies = [
  "zerocopy-derive",
 ]
 
 [[package]]
 name = "zerocopy-derive"
-version = "0.8.25"
+version = "0.8.26"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "28a6e20d751156648aa063f3800b706ee209a32c0b4d9f24be3d980b01be55ef"
+checksum = "9ecf5b4cc5364572d7f4c329661bcc82724222973f2cab6f050a4e5c22f75181"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -141,7 +141,7 @@ regex-automata = { version = "0.4.9" }
 rustc-hash = { version = "2.0.0" }
 rustc-stable-hash = { version = "0.1.2" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa", rev = "dba66f1a37acca014c2402f231ed5b361bd7d8fe" }
+salsa = { git = "https://github.com/salsa-rs/salsa", rev = "f3dc2f30f9a250618161e35600a00de7fe744953" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }

README.md

@@ -148,8 +148,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"
 
 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.12.5/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.12.5/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.12.7/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.12.7/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -182,7 +182,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.12.5
+  rev: v0.12.7
   hooks:
     # Run the linter.
     - id: ruff-check

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.12.5"
+version = "0.12.7"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }

crates/ruff_benchmark/benches/ty.rs

@@ -351,6 +351,41 @@ fn benchmark_many_tuple_assignments(criterion: &mut Criterion) {
     });
 }
 
+fn benchmark_tuple_implicit_instance_attributes(criterion: &mut Criterion) {
+    setup_rayon();
+
+    criterion.bench_function("ty_micro[many_tuple_assignments]", |b| {
+        b.iter_batched_ref(
+            || {
+                // This is a regression benchmark for a case that used to hang:
+                // https://github.com/astral-sh/ty/issues/765
+                setup_micro_case(
+                    r#"
+                    from typing import Any
+
+                    class A:
+                        foo: tuple[Any, ...]
+
+                    class B(A):
+                        def __init__(self, parent: "C", x: tuple[Any]):
+                            self.foo = parent.foo + x
+
+                    class C(A):
+                        def __init__(self, parent: B, x: tuple[Any]):
+                            self.foo = parent.foo + x
+                    "#,
+                )
+            },
+            |case| {
+                let Case { db, .. } = case;
+                let result = db.check();
+                assert_eq!(result.len(), 0);
+            },
+            BatchSize::SmallInput,
+        );
+    });
+}
+
 fn benchmark_complex_constrained_attributes_1(criterion: &mut Criterion) {
     setup_rayon();
 
@@ -630,6 +665,7 @@ criterion_group!(
     micro,
     benchmark_many_string_assignments,
     benchmark_many_tuple_assignments,
+    benchmark_tuple_implicit_instance_attributes,
     benchmark_complex_constrained_attributes_1,
     benchmark_complex_constrained_attributes_2,
     benchmark_many_enum_members,

crates/ruff_db/Cargo.toml

@@ -42,7 +42,6 @@ serde_json = { workspace = true, optional = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true, optional = true }
-unicode-width = { workspace = true }
 zip = { workspace = true }
 
 [target.'cfg(target_arch="wasm32")'.dependencies]

crates/ruff_db/src/diagnostic/mod.rs

@@ -21,7 +21,7 @@ mod stylesheet;
 /// characteristics in the inputs given to the tool. Typically, but not always,
 /// a characteristic is a deficiency. An example of a characteristic that is
 /// _not_ a deficiency is the `reveal_type` diagnostic for our type checker.
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub struct Diagnostic {
     /// The actual diagnostic.
     ///
@@ -479,7 +479,7 @@ impl Diagnostic {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 struct DiagnosticInner {
     id: DiagnosticId,
     severity: Severity,
@@ -555,7 +555,7 @@ impl Eq for RenderingSortKey<'_> {}
 /// Currently, the order in which sub-diagnostics are rendered relative to one
 /// another (for a single parent diagnostic) is the order in which they were
 /// attached to the diagnostic.
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub struct SubDiagnostic {
     /// Like with `Diagnostic`, we box the `SubDiagnostic` to make it
     /// pointer-sized.
@@ -659,7 +659,7 @@ impl SubDiagnostic {
     }
 }
 
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 struct SubDiagnosticInner {
     severity: SubDiagnosticSeverity,
     message: DiagnosticMessage,
@@ -687,7 +687,7 @@ struct SubDiagnosticInner {
 ///
 /// Messages attached to annotations should also be as brief and specific as
 /// possible. Long messages could negative impact the quality of rendering.
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub struct Annotation {
     /// The span of this annotation, corresponding to some subsequence of the
     /// user's input that we want to highlight.
@@ -807,7 +807,7 @@ impl Annotation {
 ///
 /// These tags are used to provide additional information about the annotation.
 /// and are passed through to the language server protocol.
-#[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub enum DiagnosticTag {
     /// Unused or unnecessary code. Used for unused parameters, unreachable code, etc.
     Unnecessary,
@@ -1016,7 +1016,7 @@ impl std::fmt::Display for DiagnosticId {
 ///
 /// This enum presents a unified interface to these two types for the sake of creating [`Span`]s and
 /// emitting diagnostics from both ty and ruff.
-#[derive(Debug, Clone, PartialEq, Eq, get_size2::GetSize)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, get_size2::GetSize)]
 pub enum UnifiedFile {
     Ty(File),
     Ruff(SourceFile),
@@ -1080,7 +1080,7 @@ impl DiagnosticSource {
 /// It consists of a `File` and an optional range into that file. When the
 /// range isn't present, it semantically implies that the diagnostic refers to
 /// the entire file. For example, when the file should be executable but isn't.
-#[derive(Debug, Clone, PartialEq, Eq, get_size2::GetSize)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, get_size2::GetSize)]
 pub struct Span {
     file: UnifiedFile,
     range: Option<TextRange>,
@@ -1158,7 +1158,7 @@ impl From<crate::files::FileRange> for Span {
     }
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, get_size2::GetSize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash, get_size2::GetSize)]
 pub enum Severity {
     Info,
     Warning,
@@ -1193,7 +1193,7 @@ impl Severity {
 /// This type only exists to add an additional `Help` severity that isn't present in `Severity` or
 /// used for main diagnostics. If we want to add `Severity::Help` in the future, this type could be
 /// deleted and the two combined again.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, get_size2::GetSize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash, get_size2::GetSize)]
 pub enum SubDiagnosticSeverity {
     Help,
     Info,
@@ -1428,7 +1428,7 @@ impl std::fmt::Display for ConciseMessage<'_> {
 /// In most cases, callers shouldn't need to use this. Instead, there is
 /// a blanket trait implementation for `IntoDiagnosticMessage` for
 /// anything that implements `std::fmt::Display`.
-#[derive(Clone, Debug, Eq, PartialEq, get_size2::GetSize)]
+#[derive(Clone, Debug, Eq, PartialEq, Hash, get_size2::GetSize)]
 pub struct DiagnosticMessage(Box<str>);
 
 impl DiagnosticMessage {

crates/ruff_db/src/diagnostic/render.rs

@@ -585,8 +585,7 @@ impl<'r> RenderableSnippet<'r> {
         let EscapedSourceCode {
             text: snippet,
             annotations,
-        } = replace_whitespace_and_unprintable(snippet, annotations)
-            .fix_up_empty_spans_after_line_terminator();
+        } = replace_unprintable(snippet, annotations).fix_up_empty_spans_after_line_terminator();
 
         RenderableSnippet {
             snippet,
@@ -828,13 +827,18 @@ fn relativize_path<'p>(cwd: &SystemPath, path: &'p str) -> &'p str {
     path
 }
 
-/// Given some source code and annotation ranges, this routine replaces tabs
-/// with ASCII whitespace, and unprintable characters with printable
-/// representations of them.
+/// Given some source code and annotation ranges, this routine replaces
+/// unprintable characters with printable representations of them.
 ///
 /// The source code and annotations returned are updated to reflect changes made
 /// to the source code (if any).
-fn replace_whitespace_and_unprintable<'r>(
+///
+/// We don't need to normalize whitespace, such as converting tabs to spaces,
+/// because `annotate-snippets` handles that internally. Similarly, it's safe to
+/// modify the annotation ranges by inserting 3-byte Unicode replacements
+/// because `annotate-snippets` will account for their actual width when
+/// rendering and displaying the column to the user.
+fn replace_unprintable<'r>(
     source: &'r str,
     mut annotations: Vec<RenderableAnnotation<'r>>,
 ) -> EscapedSourceCode<'r> {
@@ -866,48 +870,17 @@ fn replace_whitespace_and_unprintable<'r>(
         }
     };
 
-    const TAB_SIZE: usize = 4;
-    let mut width = 0;
-    let mut column = 0;
     let mut last_end = 0;
     let mut result = String::new();
     for (index, c) in source.char_indices() {
-        let old_width = width;
-        match c {
-            '\n' | '\r' => {
-                width = 0;
-                column = 0;
-            }
-            '\t' => {
-                let tab_offset = TAB_SIZE - (column % TAB_SIZE);
-                width += tab_offset;
-                column += tab_offset;
+        if let Some(printable) = unprintable_replacement(c) {
+            result.push_str(&source[last_end..index]);
 
-                let tab_width =
-                    u32::try_from(width - old_width).expect("small width because of tab size");
-                result.push_str(&source[last_end..index]);
+            let len = printable.text_len().to_u32();
+            update_ranges(result.text_len().to_usize(), len);
 
-                update_ranges(result.text_len().to_usize(), tab_width);
-
-                for _ in 0..tab_width {
-                    result.push(' ');
-                }
-                last_end = index + 1;
-            }
-            _ => {
-                width += unicode_width::UnicodeWidthChar::width(c).unwrap_or(0);
-                column += 1;
-
-                if let Some(printable) = unprintable_replacement(c) {
-                    result.push_str(&source[last_end..index]);
-
-                    let len = printable.text_len().to_u32();
-                    update_ranges(result.text_len().to_usize(), len);
-
-                    result.push(printable);
-                    last_end = index + 1;
-                }
-            }
+            result.push(printable);
+            last_end = index + 1;
         }
     }
 

crates/ruff_db/src/diagnostic/render/full.rs

@@ -177,4 +177,25 @@ print()
 
         Ok(())
     }
+
+    /// Ensure that the header column matches the column in the user's input, even if we've replaced
+    /// tabs with spaces for rendering purposes.
+    #[test]
+    fn tab_replacement() {
+        let mut env = TestEnvironment::new();
+        env.add("example.py", "def foo():\n\treturn 1");
+        env.format(DiagnosticFormat::Full);
+
+        let diagnostic = env.err().primary("example.py", "2:1", "2:9", "").build();
+
+        insta::assert_snapshot!(env.render(&diagnostic), @r"
+        error[test-diagnostic]: main diagnostic message
+         --> example.py:2:2
+          |
+        1 | def foo():
+        2 |     return 1
+          |     ^^^^^^^^
+          |
+        ");
+    }
 }

crates/ruff_db/src/parsed.rs

@@ -21,7 +21,7 @@ use crate::source::source_text;
 /// reflected in the changed AST offsets.
 /// The other reason is that Ruff's AST doesn't implement `Eq` which Salsa requires
 /// for determining if a query result is unchanged.
-#[salsa::tracked(returns(ref), no_eq, heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(ref), no_eq, heap_size=get_size2::heap_size)]
 pub fn parsed_module(db: &dyn Db, file: File) -> ParsedModule {
     let _span = tracing::trace_span!("parsed_module", ?file).entered();
 

crates/ruff_db/src/source.rs

@@ -9,7 +9,7 @@ use crate::Db;
 use crate::files::{File, FilePath};
 
 /// Reads the source text of a python text file (must be valid UTF8) or notebook.
-#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(heap_size=get_size2::heap_size)]
 pub fn source_text(db: &dyn Db, file: File) -> SourceText {
     let path = file.path(db);
     let _span = tracing::trace_span!("source_text", file = %path).entered();
@@ -69,21 +69,21 @@ impl SourceText {
     pub fn as_str(&self) -> &str {
         match &self.inner.kind {
             SourceTextKind::Text(source) => source,
-            SourceTextKind::Notebook(notebook) => notebook.source_code(),
+            SourceTextKind::Notebook { notebook } => notebook.source_code(),
         }
     }
 
     /// Returns the underlying notebook if this is a notebook file.
     pub fn as_notebook(&self) -> Option<&Notebook> {
         match &self.inner.kind {
-            SourceTextKind::Notebook(notebook) => Some(notebook),
+            SourceTextKind::Notebook { notebook } => Some(notebook),
             SourceTextKind::Text(_) => None,
         }
     }
 
     /// Returns `true` if this is a notebook source file.
     pub fn is_notebook(&self) -> bool {
-        matches!(&self.inner.kind, SourceTextKind::Notebook(_))
+        matches!(&self.inner.kind, SourceTextKind::Notebook { .. })
     }
 
     /// Returns `true` if there was an error when reading the content of the file.
@@ -108,7 +108,7 @@ impl std::fmt::Debug for SourceText {
             SourceTextKind::Text(text) => {
                 dbg.field(text);
             }
-            SourceTextKind::Notebook(notebook) => {
+            SourceTextKind::Notebook { notebook } => {
                 dbg.field(notebook);
             }
         }
@@ -123,23 +123,15 @@ struct SourceTextInner {
     read_error: Option<SourceTextError>,
 }
 
-#[derive(Eq, PartialEq)]
+#[derive(Eq, PartialEq, get_size2::GetSize)]
 enum SourceTextKind {
     Text(String),
-    Notebook(Box<Notebook>),
-}
-
-impl get_size2::GetSize for SourceTextKind {
-    fn get_heap_size(&self) -> usize {
-        match self {
-            SourceTextKind::Text(text) => text.get_heap_size(),
-            // TODO: The `get-size` derive does not support ignoring enum variants.
-            //
-            // Jupyter notebooks are not very relevant for memory profiling, and contain
-            // arbitrary JSON values that do not implement the `GetSize` trait.
-            SourceTextKind::Notebook(_) => 0,
-        }
-    }
+    Notebook {
+        // Jupyter notebooks are not very relevant for memory profiling, and contain
+        // arbitrary JSON values that do not implement the `GetSize` trait.
+        #[get_size(ignore)]
+        notebook: Box<Notebook>,
+    },
 }
 
 impl From<String> for SourceTextKind {
@@ -150,7 +142,9 @@ impl From<String> for SourceTextKind {
 
 impl From<Notebook> for SourceTextKind {
     fn from(notebook: Notebook) -> Self {
-        SourceTextKind::Notebook(Box::new(notebook))
+        SourceTextKind::Notebook {
+            notebook: Box::new(notebook),
+        }
     }
 }
 
@@ -163,7 +157,7 @@ pub enum SourceTextError {
 }
 
 /// Computes the [`LineIndex`] for `file`.
-#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(heap_size=get_size2::heap_size)]
 pub fn line_index(db: &dyn Db, file: File) -> LineIndex {
     let _span = tracing::trace_span!("line_index", ?file).entered();
 

crates/ruff_diagnostics/src/fix.rs

@@ -43,7 +43,7 @@ pub enum IsolationLevel {
 }
 
 /// A collection of [`Edit`] elements to be applied to a source file.
-#[derive(Debug, PartialEq, Eq, Clone, get_size2::GetSize)]
+#[derive(Debug, PartialEq, Eq, Clone, Hash, get_size2::GetSize)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Fix {
     /// The [`Edit`] elements to be applied, sorted by [`Edit::start`] in ascending order.

crates/ruff_linter/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_linter"
-version = "0.12.5"
+version = "0.12.7"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }

crates/ruff_linter/resources/test/fixtures/flake8_pyi/PYI013.py

@@ -39,6 +39,11 @@ class NonEmptyWithInit:
         pass
 
 
+class NonEmptyChildWithInlineComment:
+    value: int
+    ... # preserve me
+
+
 class EmptyClass:
     ...
 

crates/ruff_linter/resources/test/fixtures/flake8_pyi/PYI013.pyi

@@ -38,6 +38,10 @@ class NonEmptyWithInit:
     def __init__():
         pass
 
+class NonEmptyChildWithInlineComment:
+    value: int
+    ... # preserve me
+
 # Not violations
 
 class EmptyClass: ...

crates/ruff_linter/resources/test/fixtures/isort/required_imports/docstring_followed_by_continuation.py

@@ -0,0 +1,3 @@
+"""Hello, world!"""\
+
+x = 1; y = 2

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP030_0.py

@@ -59,3 +59,7 @@ kwargs = {x: x for x in range(10)}
 "{1}_{0}".format(1, 2, *args)
 
 "{1}_{0}".format(1, 2)
+
+r"\d{{1,2}} {0}".format(42)
+
+"{{{0}}}".format(123)

crates/ruff_linter/resources/test/fixtures/ruff/RUF010.py

@@ -52,3 +52,7 @@ f"{repr(lambda: 1)}"
 f"{repr(x := 2)}"
 
 f"{str(object=3)}"
+
+f"{str(x for x in [])}"
+
+f"{str((x for x in []))}"

crates/ruff_linter/src/checkers/ast/mod.rs

@@ -590,6 +590,16 @@ impl<'a> Checker<'a> {
             member,
         })
     }
+
+    /// Return the [`LintContext`] for the current analysis.
+    ///
+    /// Note that you should always prefer calling methods like `settings`, `report_diagnostic`, or
+    /// `is_rule_enabled` directly on [`Checker`] when possible. This method exists only for the
+    /// rare cases where rules or helper functions need to be accessed by both a `Checker` and a
+    /// `LintContext` in different analysis phases.
+    pub(crate) const fn context(&self) -> &'a LintContext<'a> {
+        self.context
+    }
 }
 
 pub(crate) struct TypingImporter<'a, 'b> {

crates/ruff_linter/src/importer/insertion.rs

@@ -56,13 +56,19 @@ impl<'a> Insertion<'a> {
         stylist: &Stylist,
     ) -> Insertion<'static> {
         // Skip over any docstrings.
-        let mut location = if let Some(location) = match_docstring_end(body) {
+        let mut location = if let Some(mut location) = match_docstring_end(body) {
             // If the first token after the docstring is a semicolon, insert after the semicolon as
             // an inline statement.
             if let Some(offset) = match_semicolon(locator.after(location)) {
                 return Insertion::inline(" ", location.add(offset).add(TextSize::of(';')), ";");
             }
 
+            // If the first token after the docstring is a continuation character (i.e. "\"), advance
+            // an additional row to prevent inserting in the same logical line.
+            if match_continuation(locator.after(location)).is_some() {
+                location = locator.full_line_end(location);
+            }
+
             // Otherwise, advance to the next row.
             locator.full_line_end(location)
         } else {
@@ -363,6 +369,16 @@ mod tests {
             Insertion::own_line("", TextSize::from(20), "\n")
         );
 
+        let contents = r#"
+"""Hello, world!"""\
+
+"#
+        .trim_start();
+        assert_eq!(
+            insert(contents)?,
+            Insertion::own_line("", TextSize::from(22), "\n")
+        );
+
         let contents = r"
 x = 1
 "

crates/ruff_linter/src/message/text.rs

@@ -13,7 +13,6 @@ use ruff_notebook::NotebookIndex;
 use ruff_source_file::OneIndexed;
 use ruff_text_size::{TextLen, TextRange, TextSize};
 
-use crate::line_width::{IndentWidth, LineWidthBuilder};
 use crate::message::diff::Diff;
 use crate::message::{Emitter, EmitterContext};
 use crate::settings::types::UnsafeFixes;
@@ -229,7 +228,7 @@ impl Display for MessageCodeFrame<'_> {
         let start_offset = source_code.line_start(start_index);
         let end_offset = source_code.line_end(end_index);
 
-        let source = replace_whitespace_and_unprintable(
+        let source = replace_unprintable(
             source_code.slice(TextRange::new(start_offset, end_offset)),
             self.message.expect_range() - start_offset,
         )
@@ -272,16 +271,20 @@ impl Display for MessageCodeFrame<'_> {
 }
 
 /// Given some source code and an annotation range, this routine replaces
-/// tabs with ASCII whitespace, and unprintable characters with printable
-/// representations of them.
+///  unprintable characters with printable representations of them.
 ///
 /// The source code returned has an annotation that is updated to reflect
 /// changes made to the source code (if any).
-fn replace_whitespace_and_unprintable(source: &str, annotation_range: TextRange) -> SourceCode {
+///
+/// We don't need to normalize whitespace, such as converting tabs to spaces,
+/// because `annotate-snippets` handles that internally. Similarly, it's safe to
+/// modify the annotation ranges by inserting 3-byte Unicode replacements
+/// because `annotate-snippets` will account for their actual width when
+/// rendering and displaying the column to the user.
+fn replace_unprintable(source: &str, annotation_range: TextRange) -> SourceCode {
     let mut result = String::new();
     let mut last_end = 0;
     let mut range = annotation_range;
-    let mut line_width = LineWidthBuilder::new(IndentWidth::default());
 
     // Updates the range given by the caller whenever a single byte (at
     // `index` in `source`) is replaced with `len` bytes.
@@ -310,19 +313,7 @@ fn replace_whitespace_and_unprintable(source: &str, annotation_range: TextRange)
     };
 
     for (index, c) in source.char_indices() {
-        let old_width = line_width.get();
-        line_width = line_width.add_char(c);
-
-        if matches!(c, '\t') {
-            let tab_width = u32::try_from(line_width.get() - old_width)
-                .expect("small width because of tab size");
-            result.push_str(&source[last_end..index]);
-            for _ in 0..tab_width {
-                result.push(' ');
-            }
-            last_end = index + 1;
-            update_range(index, tab_width);
-        } else if let Some(printable) = unprintable_replacement(c) {
+        if let Some(printable) = unprintable_replacement(c) {
             result.push_str(&source[last_end..index]);
             result.push(printable);
             last_end = index + 1;

crates/ruff_linter/src/rules/flake8_pyi/rules/ellipsis_in_non_empty_class_body.rs

@@ -1,10 +1,11 @@
 use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::whitespace::trailing_comment_start_offset;
 use ruff_python_ast::{Stmt, StmtExpr};
 use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
 use crate::fix;
-use crate::{Fix, FixAvailability, Violation};
+use crate::{Edit, Fix, FixAvailability, Violation};
 
 /// ## What it does
 /// Removes ellipses (`...`) in otherwise non-empty class bodies.
@@ -50,15 +51,21 @@ pub(crate) fn ellipsis_in_non_empty_class_body(checker: &Checker, body: &[Stmt])
     }
 
     for stmt in body {
-        let Stmt::Expr(StmtExpr { value, .. }) = &stmt else {
+        let Stmt::Expr(StmtExpr { value, .. }) = stmt else {
             continue;
         };
 
         if value.is_ellipsis_literal_expr() {
             let mut diagnostic =
                 checker.report_diagnostic(EllipsisInNonEmptyClassBody, stmt.range());
-            let edit =
-                fix::edits::delete_stmt(stmt, Some(stmt), checker.locator(), checker.indexer());
+
+            // Try to preserve trailing comment if it exists
+            let edit = if let Some(index) = trailing_comment_start_offset(stmt, checker.source()) {
+                Edit::range_deletion(stmt.range().add_end(index))
+            } else {
+                fix::edits::delete_stmt(stmt, Some(stmt), checker.locator(), checker.indexer())
+            };
+
             diagnostic.set_fix(Fix::safe_edit(edit).isolate(Checker::isolation(
                 checker.semantic().current_statement_id(),
             )));

crates/ruff_linter/src/rules/flake8_pyi/snapshots/ruff_linter__rules__flake8_pyi__tests__PYI013_PYI013.py.snap

@@ -145,3 +145,22 @@ PYI013.py:36:5: PYI013 [*] Non-empty class body must not contain `...`
 37 36 | 
 38 37 |     def __init__():
 39 38 |         pass
+
+PYI013.py:44:5: PYI013 [*] Non-empty class body must not contain `...`
+   |
+42 | class NonEmptyChildWithInlineComment:
+43 |     value: int
+44 |     ... # preserve me
+   |     ^^^ PYI013
+   |
+   = help: Remove unnecessary `...`
+
+ℹ Safe fix
+41 41 | 
+42 42 | class NonEmptyChildWithInlineComment:
+43 43 |     value: int
+44    |-    ... # preserve me
+   44 |+    # preserve me
+45 45 | 
+46 46 | 
+47 47 | class EmptyClass:

crates/ruff_linter/src/rules/flake8_pyi/snapshots/ruff_linter__rules__flake8_pyi__tests__PYI013_PYI013.pyi.snap

@@ -17,9 +17,10 @@ PYI013.pyi:5:5: PYI013 [*] Non-empty class body must not contain `...`
 3 3 | class OneAttributeClass:
 4 4 |     value: int
 5   |-    ...  # Error
-6 5 | 
-7 6 | class OneAttributeClass2:
-8 7 |     ...  # Error
+  5 |+    # Error
+6 6 | 
+7 7 | class OneAttributeClass2:
+8 8 |     ...  # Error
 
 PYI013.pyi:8:5: PYI013 [*] Non-empty class body must not contain `...`
   |
@@ -35,9 +36,10 @@ PYI013.pyi:8:5: PYI013 [*] Non-empty class body must not contain `...`
 6 6 | 
 7 7 | class OneAttributeClass2:
 8   |-    ...  # Error
-9 8 |     value: int
-10 9 | 
-11 10 | class MyClass:
+  8 |+    # Error
+9 9 |     value: int
+10 10 | 
+11 11 | class MyClass:
 
 PYI013.pyi:12:5: PYI013 [*] Non-empty class body must not contain `...`
    |
@@ -91,9 +93,10 @@ PYI013.pyi:17:5: PYI013 [*] Non-empty class body must not contain `...`
 15 15 | class TwoEllipsesClass:
 16 16 |     ...
 17    |-    ...  # Error
-18 17 | 
-19 18 | class DocstringClass:
-20 19 |     """
+   17 |+    # Error
+18 18 | 
+19 19 | class DocstringClass:
+20 20 |     """
 
 PYI013.pyi:24:5: PYI013 [*] Non-empty class body must not contain `...`
    |
@@ -111,9 +114,10 @@ PYI013.pyi:24:5: PYI013 [*] Non-empty class body must not contain `...`
 22 22 |     """
 23 23 | 
 24    |-    ...  # Error
-25 24 | 
-26 25 | class NonEmptyChild(Exception):
-27 26 |     value: int
+   24 |+    # Error
+25 25 | 
+26 26 | class NonEmptyChild(Exception):
+27 27 |     value: int
 
 PYI013.pyi:28:5: PYI013 [*] Non-empty class body must not contain `...`
    |
@@ -131,9 +135,10 @@ PYI013.pyi:28:5: PYI013 [*] Non-empty class body must not contain `...`
 26 26 | class NonEmptyChild(Exception):
 27 27 |     value: int
 28    |-    ...  # Error
-29 28 | 
-30 29 | class NonEmptyChild2(Exception):
-31 30 |     ...  # Error
+   28 |+    # Error
+29 29 | 
+30 30 | class NonEmptyChild2(Exception):
+31 31 |     ...  # Error
 
 PYI013.pyi:31:5: PYI013 [*] Non-empty class body must not contain `...`
    |
@@ -149,9 +154,10 @@ PYI013.pyi:31:5: PYI013 [*] Non-empty class body must not contain `...`
 29 29 | 
 30 30 | class NonEmptyChild2(Exception):
 31    |-    ...  # Error
-32 31 |     value: int
-33 32 | 
-34 33 | class NonEmptyWithInit:
+   31 |+    # Error
+32 32 |     value: int
+33 33 | 
+34 34 | class NonEmptyWithInit:
 
 PYI013.pyi:36:5: PYI013 [*] Non-empty class body must not contain `...`
    |
@@ -169,6 +175,28 @@ PYI013.pyi:36:5: PYI013 [*] Non-empty class body must not contain `...`
 34 34 | class NonEmptyWithInit:
 35 35 |     value: int
 36    |-    ...  # Error
-37 36 | 
-38 37 |     def __init__():
-39 38 |         pass
+   36 |+    # Error
+37 37 | 
+38 38 |     def __init__():
+39 39 |         pass
+
+PYI013.pyi:43:5: PYI013 [*] Non-empty class body must not contain `...`
+   |
+41 | class NonEmptyChildWithInlineComment:
+42 |     value: int
+43 |     ... # preserve me
+   |     ^^^ PYI013
+44 |
+45 | # Not violations
+   |
+   = help: Remove unnecessary `...`
+
+ℹ Safe fix
+40 40 | 
+41 41 | class NonEmptyChildWithInlineComment:
+42 42 |     value: int
+43    |-    ... # preserve me
+   43 |+    # preserve me
+44 44 | 
+45 45 | # Not violations
+46 46 |

crates/ruff_linter/src/rules/isort/mod.rs

@@ -794,6 +794,7 @@ mod tests {
     #[test_case(Path::new("comments_and_newlines.py"))]
     #[test_case(Path::new("docstring.py"))]
     #[test_case(Path::new("docstring.pyi"))]
+    #[test_case(Path::new("docstring_followed_by_continuation.py"))]
     #[test_case(Path::new("docstring_only.py"))]
     #[test_case(Path::new("docstring_with_continuation.py"))]
     #[test_case(Path::new("docstring_with_semicolon.py"))]
@@ -828,6 +829,7 @@ mod tests {
     #[test_case(Path::new("comments_and_newlines.py"))]
     #[test_case(Path::new("docstring.py"))]
     #[test_case(Path::new("docstring.pyi"))]
+    #[test_case(Path::new("docstring_followed_by_continuation.py"))]
     #[test_case(Path::new("docstring_only.py"))]
     #[test_case(Path::new("docstring_with_continuation.py"))]
     #[test_case(Path::new("docstring_with_semicolon.py"))]

crates/ruff_linter/src/rules/isort/snapshots/ruff_linter__rules__isort__tests__required_import_docstring_followed_by_continuation.py.snap

@@ -0,0 +1,9 @@
+---
+source: crates/ruff_linter/src/rules/isort/mod.rs
+---
+docstring_followed_by_continuation.py:1:1: I002 [*] Missing required import: `from __future__ import annotations`
+ℹ Safe fix
+1 1 | """Hello, world!"""\
+2 2 | 
+  3 |+from __future__ import annotations
+3 4 | x = 1; y = 2

crates/ruff_linter/src/rules/isort/snapshots/ruff_linter__rules__isort__tests__required_import_with_alias_docstring_followed_by_continuation.py.snap

@@ -0,0 +1,9 @@
+---
+source: crates/ruff_linter/src/rules/isort/mod.rs
+---
+docstring_followed_by_continuation.py:1:1: I002 [*] Missing required import: `from __future__ import annotations as _annotations`
+ℹ Safe fix
+1 1 | """Hello, world!"""\
+2 2 | 
+  3 |+from __future__ import annotations as _annotations
+3 4 | x = 1; y = 2

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E101_E101.py.snap

@@ -15,8 +15,8 @@ E101.py:15:1: E101 Indentation contains mixed spaces and tabs
    |
 13 | def func_mixed_start_with_space():
 14 |     # E101
-15 |                print("mixed starts with space")
-   | ^^^^^^^^^^^^^^^ E101
+15 |                     print("mixed starts with space")
+   | ^^^^^^^^^^^^^^^^^^^^ E101
 16 |
 17 | def xyz():
    |
@@ -25,6 +25,6 @@ E101.py:19:1: E101 Indentation contains mixed spaces and tabs
    |
 17 | def xyz():
 18 |     # E101
-19 |     print("xyz");
-   | ^^^^ E101
+19 |        print("xyz");
+   | ^^^^^^^ E101
    |

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E201_E20.py.snap

@@ -47,7 +47,7 @@ E20.py:6:15: E201 [*] Whitespace after '{'
 6 | spam(ham[1], { eggs: 2})
   |               ^ E201
 7 | #: E201:1:6
-8 | spam(   ham[1], {eggs: 2})
+8 | spam(    ham[1], {eggs: 2})
   |
   = help: Remove whitespace before '{'
 
@@ -65,10 +65,10 @@ E20.py:8:6: E201 [*] Whitespace after '('
    |
  6 | spam(ham[1], { eggs: 2})
  7 | #: E201:1:6
- 8 | spam(   ham[1], {eggs: 2})
-   |      ^^^ E201
+ 8 | spam(    ham[1], {eggs: 2})
+   |      ^^^^ E201
  9 | #: E201:1:10
-10 | spam(ham[   1], {eggs: 2})
+10 | spam(ham[    1], {eggs: 2})
    |
    = help: Remove whitespace before '('
 
@@ -84,12 +84,12 @@ E20.py:8:6: E201 [*] Whitespace after '('
 
 E20.py:10:10: E201 [*] Whitespace after '['
    |
- 8 | spam(   ham[1], {eggs: 2})
+ 8 | spam(    ham[1], {eggs: 2})
  9 | #: E201:1:10
-10 | spam(ham[   1], {eggs: 2})
-   |          ^^^ E201
+10 | spam(ham[    1], {eggs: 2})
+   |          ^^^^ E201
 11 | #: E201:1:15
-12 | spam(ham[1], {  eggs: 2})
+12 | spam(ham[1], {    eggs: 2})
    |
    = help: Remove whitespace before '['
 
@@ -105,10 +105,10 @@ E20.py:10:10: E201 [*] Whitespace after '['
 
 E20.py:12:15: E201 [*] Whitespace after '{'
    |
-10 | spam(ham[   1], {eggs: 2})
+10 | spam(ham[    1], {eggs: 2})
 11 | #: E201:1:15
-12 | spam(ham[1], {  eggs: 2})
-   |               ^^ E201
+12 | spam(ham[1], {    eggs: 2})
+   |               ^^^^ E201
 13 | #: Okay
 14 | spam(ham[1], {eggs: 2})
    |

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E202_E20.py.snap

@@ -49,7 +49,7 @@ E20.py:23:11: E202 [*] Whitespace before ']'
 23 | spam(ham[1 ], {eggs: 2})
    |           ^ E202
 24 | #: E202:1:23
-25 | spam(ham[1], {eggs: 2}  )
+25 | spam(ham[1], {eggs: 2}    )
    |
    = help: Remove whitespace before ']'
 
@@ -67,10 +67,10 @@ E20.py:25:23: E202 [*] Whitespace before ')'
    |
 23 | spam(ham[1 ], {eggs: 2})
 24 | #: E202:1:23
-25 | spam(ham[1], {eggs: 2}  )
-   |                       ^^ E202
+25 | spam(ham[1], {eggs: 2}    )
+   |                       ^^^^ E202
 26 | #: E202:1:22
-27 | spam(ham[1], {eggs: 2   })
+27 | spam(ham[1], {eggs: 2    })
    |
    = help: Remove whitespace before ')'
 
@@ -86,12 +86,12 @@ E20.py:25:23: E202 [*] Whitespace before ')'
 
 E20.py:27:22: E202 [*] Whitespace before '}'
    |
-25 | spam(ham[1], {eggs: 2}  )
+25 | spam(ham[1], {eggs: 2}    )
 26 | #: E202:1:22
-27 | spam(ham[1], {eggs: 2   })
-   |                      ^^^ E202
+27 | spam(ham[1], {eggs: 2    })
+   |                      ^^^^ E202
 28 | #: E202:1:11
-29 | spam(ham[1  ], {eggs: 2})
+29 | spam(ham[1    ], {eggs: 2})
    |
    = help: Remove whitespace before '}'
 
@@ -107,10 +107,10 @@ E20.py:27:22: E202 [*] Whitespace before '}'
 
 E20.py:29:11: E202 [*] Whitespace before ']'
    |
-27 | spam(ham[1], {eggs: 2   })
+27 | spam(ham[1], {eggs: 2    })
 28 | #: E202:1:11
-29 | spam(ham[1  ], {eggs: 2})
-   |           ^^ E202
+29 | spam(ham[1    ], {eggs: 2})
+   |           ^^^^ E202
 30 | #: Okay
 31 | spam(ham[1], {eggs: 2})
    |

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E203_E20.py.snap

@@ -25,8 +25,8 @@ E20.py:55:10: E203 [*] Whitespace before ':'
    |
 53 |     x, y = y, x
 54 | #: E203:1:10
-55 | if x == 4   :
-   |          ^^^ E203
+55 | if x == 4    :
+   |          ^^^^ E203
 56 |     print(x, y)
 57 |     x, y = y, x
    |
@@ -67,8 +67,8 @@ E20.py:63:16: E203 [*] Whitespace before ';'
    |
 61 | #: E203:2:15 E702:2:16
 62 | if x == 4:
-63 |     print(x, y) ; x, y = y, x
-   |                ^ E203
+63 |     print(x, y)    ; x, y = y, x
+   |                ^^^^ E203
 64 | #: E203:3:13
 65 | if x == 4:
    |

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E223_E22.py.snap

@@ -1,13 +1,12 @@
 ---
 source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
-snapshot_kind: text
 ---
 E22.py:43:2: E223 [*] Tab before operator
    |
 41 | #: E223
 42 | foobart = 4
-43 | a   = 3  # aligned with tab
-   |  ^^^ E223
+43 | a    = 3  # aligned with tab
+   |  ^^^^ E223
 44 | #:
    |
    = help: Replace with single space

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E242_E24.py.snap

@@ -1,13 +1,12 @@
 ---
 source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
-snapshot_kind: text
 ---
 E24.py:6:8: E242 [*] Tab after comma
   |
 4 | b = (1, 20)
 5 | #: E242
-6 | a = (1, 2)  # tab before 2
-  |        ^ E242
+6 | a = (1,    2)  # tab before 2
+  |        ^^^^ E242
 7 | #: Okay
 8 | b = (1, 20)  # space before 20
   |

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E271_E27.py.snap

@@ -66,7 +66,7 @@ E27.py:8:3: E271 [*] Multiple spaces after keyword
 
 E27.py:15:6: E271 [*] Multiple spaces after keyword
    |
-13 | True        and False
+13 | True        and    False
 14 | #: E271
 15 | a and  b
    |      ^^ E271

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E272_E27.py.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
-snapshot_kind: text
 ---
 E27.py:21:2: E272 [*] Multiple spaces before keyword
    |
@@ -51,7 +50,7 @@ E27.py:25:5: E272 [*] Multiple spaces before keyword
 25 | this  and False
    |     ^^ E272
 26 | #: E273
-27 | a and   b
+27 | a and    b
    |
    = help: Replace with single space
 

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E273_E27.py.snap

@@ -8,7 +8,7 @@ E27.py:11:9: E273 [*] Tab after keyword
 11 | True and        False
    |         ^^^^^^^^ E273
 12 | #: E273 E274
-13 | True        and False
+13 | True        and    False
    |
    = help: Replace with single space
 
@@ -26,7 +26,7 @@ E27.py:13:5: E273 [*] Tab after keyword
    |
 11 | True and        False
 12 | #: E273 E274
-13 | True        and False
+13 | True        and    False
    |     ^^^^^^^^ E273
 14 | #: E271
 15 | a and  b
@@ -47,8 +47,8 @@ E27.py:13:10: E273 [*] Tab after keyword
    |
 11 | True and        False
 12 | #: E273 E274
-13 | True        and False
-   |                ^ E273
+13 | True        and    False
+   |                ^^^^ E273
 14 | #: E271
 15 | a and  b
    |
@@ -68,10 +68,10 @@ E27.py:27:6: E273 [*] Tab after keyword
    |
 25 | this  and False
 26 | #: E273
-27 | a and   b
-   |      ^^^ E273
+27 | a and    b
+   |      ^^^^ E273
 28 | #: E274
-29 | a       and b
+29 | a        and b
    |
    = help: Replace with single space
 
@@ -87,10 +87,10 @@ E27.py:27:6: E273 [*] Tab after keyword
 
 E27.py:31:10: E273 [*] Tab after keyword
    |
-29 | a       and b
+29 | a        and b
 30 | #: E273 E274
-31 | this        and False
-   |                ^ E273
+31 | this        and    False
+   |                ^^^^ E273
 32 | #: Okay
 33 | from u import (a, b)
    |

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__E274_E27.py.snap

@@ -1,15 +1,14 @@
 ---
 source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
-snapshot_kind: text
 ---
 E27.py:29:2: E274 [*] Tab before keyword
    |
-27 | a and   b
+27 | a and    b
 28 | #: E274
-29 | a       and b
-   |  ^^^^^^^ E274
+29 | a        and b
+   |  ^^^^^^^^ E274
 30 | #: E273 E274
-31 | this        and False
+31 | this        and    False
    |
    = help: Replace with single space
 
@@ -25,9 +24,9 @@ E27.py:29:2: E274 [*] Tab before keyword
 
 E27.py:31:5: E274 [*] Tab before keyword
    |
-29 | a       and b
+29 | a        and b
 30 | #: E273 E274
-31 | this        and False
+31 | this        and    False
    |     ^^^^^^^^ E274
 32 | #: Okay
 33 | from u import (a, b)

crates/ruff_linter/src/rules/pycodestyle/snapshots/ruff_linter__rules__pycodestyle__tests__W191_W19.py.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/ruff_linter/src/rules/pycodestyle/mod.rs
-snapshot_kind: text
 ---
 W19.py:1:1: W191 Indentation contains tabs
   |
@@ -371,7 +370,7 @@ W19.py:157:1: W191 Indentation contains tabs
 156 | f"test{
 157 |     tab_indented_should_be_flagged
     | ^^^^ W191
-158 | }   <- this tab is fine"
+158 | }    <- this tab is fine"
     |
 
 W19.py:161:1: W191 Indentation contains tabs
@@ -379,5 +378,5 @@ W19.py:161:1: W191 Indentation contains tabs
 160 | f"""test{
 161 |     tab_indented_should_be_flagged
     | ^^^^ W191
-162 | }   <- this tab is fine"""
+162 | }    <- this tab is fine"""
     |

crates/ruff_linter/src/rules/pyupgrade/rules/format_literals.rs

@@ -124,10 +124,20 @@ fn is_sequential(indices: &[usize]) -> bool {
     indices.iter().enumerate().all(|(idx, value)| idx == *value)
 }
 
-// An opening curly brace, followed by any integer, followed by any text,
-// followed by a closing brace.
-static FORMAT_SPECIFIER: LazyLock<Regex> =
-    LazyLock::new(|| Regex::new(r"\{(?P<int>\d+)(?P<fmt>.*?)}").unwrap());
+static FORMAT_SPECIFIER: LazyLock<Regex> = LazyLock::new(|| {
+    Regex::new(
+        r"(?x)
+            (?P<prefix>
+                ^|[^{]|(?:\{{2})+  # preceded by nothing, a non-brace, or an even number of braces
+            )
+            \{                     # opening curly brace
+                (?P<int>\d+)       # followed by any integer
+                (?P<fmt>.*?)       # followed by any text
+            }                      # followed by a closing brace
+        ",
+    )
+    .unwrap()
+});
 
 /// Remove the explicit positional indices from a format string.
 fn remove_specifiers<'a>(value: &mut Expression<'a>, arena: &'a typed_arena::Arena<String>) {
@@ -135,7 +145,7 @@ fn remove_specifiers<'a>(value: &mut Expression<'a>, arena: &'a typed_arena::Are
         Expression::SimpleString(expr) => {
             expr.value = arena.alloc(
                 FORMAT_SPECIFIER
-                    .replace_all(expr.value, "{$fmt}")
+                    .replace_all(expr.value, "$prefix{$fmt}")
                     .to_string(),
             );
         }
@@ -146,7 +156,7 @@ fn remove_specifiers<'a>(value: &mut Expression<'a>, arena: &'a typed_arena::Are
                     libcst_native::String::Simple(string) => {
                         string.value = arena.alloc(
                             FORMAT_SPECIFIER
-                                .replace_all(string.value, "{$fmt}")
+                                .replace_all(string.value, "$prefix{$fmt}")
                                 .to_string(),
                         );
                     }

crates/ruff_linter/src/rules/pyupgrade/snapshots/ruff_linter__rules__pyupgrade__tests__UP030_0.py.snap

@@ -481,6 +481,7 @@ UP030_0.py:59:1: UP030 [*] Use implicit references for positional format fields
    59 |+"{}_{}".format(2, 1, )
 60 60 | 
 61 61 | "{1}_{0}".format(1, 2)
+62 62 | 
 
 UP030_0.py:61:1: UP030 [*] Use implicit references for positional format fields
    |
@@ -488,6 +489,8 @@ UP030_0.py:61:1: UP030 [*] Use implicit references for positional format fields
 60 |
 61 | "{1}_{0}".format(1, 2)
    | ^^^^^^^^^^^^^^^^^^^^^^ UP030
+62 |
+63 | r"\d{{1,2}} {0}".format(42)
    |
    = help: Remove explicit positional indices
 
@@ -497,3 +500,42 @@ UP030_0.py:61:1: UP030 [*] Use implicit references for positional format fields
 60 60 | 
 61    |-"{1}_{0}".format(1, 2)
    61 |+"{}_{}".format(2, 1)
+62 62 | 
+63 63 | r"\d{{1,2}} {0}".format(42)
+64 64 | 
+
+UP030_0.py:63:1: UP030 [*] Use implicit references for positional format fields
+   |
+61 | "{1}_{0}".format(1, 2)
+62 |
+63 | r"\d{{1,2}} {0}".format(42)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ UP030
+64 |
+65 | "{{{0}}}".format(123)
+   |
+   = help: Remove explicit positional indices
+
+ℹ Unsafe fix
+60 60 | 
+61 61 | "{1}_{0}".format(1, 2)
+62 62 | 
+63    |-r"\d{{1,2}} {0}".format(42)
+   63 |+r"\d{{1,2}} {}".format(42)
+64 64 | 
+65 65 | "{{{0}}}".format(123)
+
+UP030_0.py:65:1: UP030 [*] Use implicit references for positional format fields
+   |
+63 | r"\d{{1,2}} {0}".format(42)
+64 |
+65 | "{{{0}}}".format(123)
+   | ^^^^^^^^^^^^^^^^^^^^^ UP030
+   |
+   = help: Remove explicit positional indices
+
+ℹ Unsafe fix
+62 62 | 
+63 63 | r"\d{{1,2}} {0}".format(42)
+64 64 | 
+65    |-"{{{0}}}".format(123)
+   65 |+"{{{}}}".format(123)

crates/ruff_linter/src/rules/ruff/rules/ambiguous_unicode_character.rs

@@ -12,7 +12,6 @@ use crate::checkers::ast::{Checker, LintContext};
 use crate::preview::is_unicode_to_unicode_confusables_enabled;
 use crate::rules::ruff::rules::Context;
 use crate::rules::ruff::rules::confusables::confusable;
-use crate::settings::LinterSettings;
 
 /// ## What it does
 /// Checks for ambiguous Unicode characters in strings.
@@ -180,9 +179,7 @@ pub(crate) fn ambiguous_unicode_character_comment(
     range: TextRange,
 ) {
     let text = locator.slice(range);
-    for candidate in ambiguous_unicode_character(text, range, context.settings()) {
-        candidate.into_diagnostic(Context::Comment, context);
-    }
+    ambiguous_unicode_character(text, range, Context::Comment, context);
 }
 
 /// RUF001, RUF002
@@ -203,22 +200,19 @@ pub(crate) fn ambiguous_unicode_character_string(checker: &Checker, string_like:
         match part {
             ast::StringLikePart::String(string_literal) => {
                 let text = checker.locator().slice(string_literal);
-                for candidate in
-                    ambiguous_unicode_character(text, string_literal.range(), checker.settings())
-                {
-                    candidate.report_diagnostic(checker, context);
-                }
+                ambiguous_unicode_character(
+                    text,
+                    string_literal.range(),
+                    context,
+                    checker.context(),
+                );
             }
             ast::StringLikePart::Bytes(_) => {}
             ast::StringLikePart::FString(FString { elements, .. })
             | ast::StringLikePart::TString(TString { elements, .. }) => {
                 for literal in elements.literals() {
                     let text = checker.locator().slice(literal);
-                    for candidate in
-                        ambiguous_unicode_character(text, literal.range(), checker.settings())
-                    {
-                        candidate.report_diagnostic(checker, context);
-                    }
+                    ambiguous_unicode_character(text, literal.range(), context, checker.context());
                 }
             }
         }
@@ -228,13 +222,12 @@ pub(crate) fn ambiguous_unicode_character_string(checker: &Checker, string_like:
 fn ambiguous_unicode_character(
     text: &str,
     range: TextRange,
-    settings: &LinterSettings,
-) -> Vec<Candidate> {
-    let mut candidates = Vec::new();
-
+    context: Context,
+    lint_context: &LintContext,
+) {
     // Most of the time, we don't need to check for ambiguous unicode characters at all.
     if text.is_ascii() {
-        return candidates;
+        return;
     }
 
     // Iterate over the "words" in the text.
@@ -246,7 +239,7 @@ fn ambiguous_unicode_character(
             if !word_candidates.is_empty() {
                 if word_flags.is_candidate_word() {
                     for candidate in word_candidates.drain(..) {
-                        candidates.push(candidate);
+                        candidate.into_diagnostic(context, lint_context);
                     }
                 }
                 word_candidates.clear();
@@ -257,21 +250,23 @@ fn ambiguous_unicode_character(
             // case, it's always included as a diagnostic.
             if !current_char.is_ascii() {
                 if let Some(representant) = confusable(current_char as u32).filter(|representant| {
-                    is_unicode_to_unicode_confusables_enabled(settings) || representant.is_ascii()
+                    is_unicode_to_unicode_confusables_enabled(lint_context.settings())
+                        || representant.is_ascii()
                 }) {
                     let candidate = Candidate::new(
                         TextSize::try_from(relative_offset).unwrap() + range.start(),
                         current_char,
                         representant,
                     );
-                    candidates.push(candidate);
+                    candidate.into_diagnostic(context, lint_context);
                 }
             }
         } else if current_char.is_ascii() {
             // The current word contains at least one ASCII character.
             word_flags |= WordFlags::ASCII;
         } else if let Some(representant) = confusable(current_char as u32).filter(|representant| {
-            is_unicode_to_unicode_confusables_enabled(settings) || representant.is_ascii()
+            is_unicode_to_unicode_confusables_enabled(lint_context.settings())
+                || representant.is_ascii()
         }) {
             // The current word contains an ambiguous unicode character.
             word_candidates.push(Candidate::new(
@@ -289,13 +284,11 @@ fn ambiguous_unicode_character(
     if !word_candidates.is_empty() {
         if word_flags.is_candidate_word() {
             for candidate in word_candidates.drain(..) {
-                candidates.push(candidate);
+                candidate.into_diagnostic(context, lint_context);
             }
         }
         word_candidates.clear();
     }
-
-    candidates
 }
 
 bitflags! {
@@ -373,39 +366,6 @@ impl Candidate {
             };
         }
     }
-
-    fn report_diagnostic(self, checker: &Checker, context: Context) {
-        if !checker
-            .settings()
-            .allowed_confusables
-            .contains(&self.confusable)
-        {
-            let char_range = TextRange::at(self.offset, self.confusable.text_len());
-            match context {
-                Context::String => checker.report_diagnostic_if_enabled(
-                    AmbiguousUnicodeCharacterString {
-                        confusable: self.confusable,
-                        representant: self.representant,
-                    },
-                    char_range,
-                ),
-                Context::Docstring => checker.report_diagnostic_if_enabled(
-                    AmbiguousUnicodeCharacterDocstring {
-                        confusable: self.confusable,
-                        representant: self.representant,
-                    },
-                    char_range,
-                ),
-                Context::Comment => checker.report_diagnostic_if_enabled(
-                    AmbiguousUnicodeCharacterComment {
-                        confusable: self.confusable,
-                        representant: self.representant,
-                    },
-                    char_range,
-                ),
-            };
-        }
-    }
 }
 
 struct NamedUnicode(char);

crates/ruff_linter/src/rules/ruff/rules/explicit_f_string_type_conversion.rs

@@ -149,8 +149,7 @@ fn convert_call_to_conversion_flag(
             formatted_string_expression.whitespace_before_expression = space();
         }
 
-        formatted_string_expression.expression = if needs_paren(OperatorPrecedence::from_expr(arg))
-        {
+        formatted_string_expression.expression = if needs_paren_expr(arg) {
             call.args[0]
                 .value
                 .clone()
@@ -178,6 +177,16 @@ fn needs_paren(precedence: OperatorPrecedence) -> bool {
     precedence <= OperatorPrecedence::Lambda
 }
 
+fn needs_paren_expr(arg: &Expr) -> bool {
+    // Generator expressions need to be parenthesized in f-string expressions
+    if let Some(generator) = arg.as_generator_expr() {
+        return !generator.parenthesized;
+    }
+
+    // Check precedence for other expressions
+    needs_paren(OperatorPrecedence::from_expr(arg))
+}
+
 /// Represents the three built-in Python conversion functions that can be replaced
 /// with f-string conversion flags.
 #[derive(Copy, Clone)]

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF010_RUF010.py.snap

@@ -359,6 +359,7 @@ RUF010.py:52:4: RUF010 [*] Use explicit conversion flag
    52 |+f"{(x := 2)!r}"
 53 53 | 
 54 54 | f"{str(object=3)}"
+55 55 | 
 
 RUF010.py:54:4: RUF010 [*] Use explicit conversion flag
    |
@@ -366,6 +367,8 @@ RUF010.py:54:4: RUF010 [*] Use explicit conversion flag
 53 |
 54 | f"{str(object=3)}"
    |    ^^^^^^^^^^^^^ RUF010
+55 |
+56 | f"{str(x for x in [])}"
    |
    = help: Replace with conversion flag
 
@@ -375,3 +378,42 @@ RUF010.py:54:4: RUF010 [*] Use explicit conversion flag
 53 53 | 
 54    |-f"{str(object=3)}"
    54 |+f"{3!s}"
+55 55 | 
+56 56 | f"{str(x for x in [])}"
+57 57 | 
+
+RUF010.py:56:4: RUF010 [*] Use explicit conversion flag
+   |
+54 | f"{str(object=3)}"
+55 |
+56 | f"{str(x for x in [])}"
+   |    ^^^^^^^^^^^^^^^^^^ RUF010
+57 |
+58 | f"{str((x for x in []))}"
+   |
+   = help: Replace with conversion flag
+
+ℹ Safe fix
+53 53 | 
+54 54 | f"{str(object=3)}"
+55 55 | 
+56    |-f"{str(x for x in [])}"
+   56 |+f"{(x for x in [])!s}"
+57 57 | 
+58 58 | f"{str((x for x in []))}"
+
+RUF010.py:58:4: RUF010 [*] Use explicit conversion flag
+   |
+56 | f"{str(x for x in [])}"
+57 |
+58 | f"{str((x for x in []))}"
+   |    ^^^^^^^^^^^^^^^^^^^^ RUF010
+   |
+   = help: Replace with conversion flag
+
+ℹ Safe fix
+55 55 | 
+56 56 | f"{str(x for x in [])}"
+57 57 | 
+58    |-f"{str((x for x in []))}"
+   58 |+f"{(x for x in [])!s}"

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__preview__RUF054_RUF054.py.snap

@@ -22,7 +22,7 @@ RUF054.py:10:3: RUF054 Indented form feed
 RUF054.py:13:2: RUF054 Indented form feed
    |
 12 | def _():
-13 |        pass
+13 |         pass
    |     ^ RUF054
 14 |
 15 | if False:

crates/ruff_source_file/src/lib.rs

@@ -1,5 +1,6 @@
 use std::cmp::Ordering;
 use std::fmt::{Debug, Display, Formatter};
+use std::hash::Hash;
 use std::sync::{Arc, OnceLock};
 
 #[cfg(feature = "serde")]
@@ -162,7 +163,7 @@ impl SourceFileBuilder {
 /// A source file that is identified by its name. Optionally stores the source code and [`LineIndex`].
 ///
 /// Cloning a [`SourceFile`] is cheap, because it only requires bumping a reference count.
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq, Hash)]
 #[cfg_attr(feature = "get-size", derive(get_size2::GetSize))]
 pub struct SourceFile {
     inner: Arc<SourceFileInner>,
@@ -241,6 +242,13 @@ impl PartialEq for SourceFileInner {
 
 impl Eq for SourceFileInner {}
 
+impl Hash for SourceFileInner {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.name.hash(state);
+        self.code.hash(state);
+    }
+}
+
 /// The line and column of an offset in a source file.
 ///
 /// See [`LineIndex::line_column`] for more information.

crates/ruff_wasm/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_wasm"
-version = "0.12.5"
+version = "0.12.7"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }

crates/ty_ide/src/completion.rs

@@ -66,9 +66,9 @@ enum CompletionTargetTokens<'t> {
     /// A token was found under the cursor, but it didn't
     /// match any of our anticipated token patterns.
     Generic { token: &'t Token },
-    /// No token was found, but we have the offset of the
-    /// cursor.
-    Unknown { offset: TextSize },
+    /// No token was found. We generally treat this like
+    /// `Generic` (i.e., offer scope based completions).
+    Unknown,
 }
 
 impl<'t> CompletionTargetTokens<'t> {
@@ -78,7 +78,7 @@ impl<'t> CompletionTargetTokens<'t> {
         static OBJECT_DOT_NON_EMPTY: [TokenKind; 2] = [TokenKind::Dot, TokenKind::Name];
 
         let offset = match parsed.tokens().at_offset(offset) {
-            TokenAt::None => return Some(CompletionTargetTokens::Unknown { offset }),
+            TokenAt::None => return Some(CompletionTargetTokens::Unknown),
             TokenAt::Single(tok) => tok.end(),
             TokenAt::Between(_, tok) => tok.start(),
         };
@@ -122,7 +122,7 @@ impl<'t> CompletionTargetTokens<'t> {
                 return None;
             } else {
                 let Some(last) = before.last() else {
-                    return Some(CompletionTargetTokens::Unknown { offset });
+                    return Some(CompletionTargetTokens::Unknown);
                 };
                 CompletionTargetTokens::Generic { token: last }
             },
@@ -171,7 +171,7 @@ impl<'t> CompletionTargetTokens<'t> {
                     node: covering_node.node(),
                 })
             }
-            CompletionTargetTokens::Unknown { offset } => {
+            CompletionTargetTokens::Unknown => {
                 let range = TextRange::empty(offset);
                 let covering_node = covering_node(parsed.syntax().into(), range);
                 Some(CompletionTargetAst::Scoped {

crates/ty_ide/src/goto_references.rs

@@ -38,7 +38,7 @@ mod tests {
 
     impl CursorTest {
         fn references(&self) -> String {
-            let Some(reference_results) =
+            let Some(mut reference_results) =
                 goto_references(&self.db, self.cursor.file, self.cursor.offset, true)
             else {
                 return "No references found".to_string();
@@ -48,6 +48,8 @@ mod tests {
                 return "No references found".to_string();
             }
 
+            reference_results.sort_by_key(ReferenceTarget::file);
+
             self.render_diagnostics(reference_results.into_iter().enumerate().map(
                 |(i, ref_item)| -> ReferenceResult {
                     ReferenceResult {

crates/ty_project/src/db.rs

@@ -1,5 +1,5 @@
 use std::fmt::Formatter;
-use std::panic::{AssertUnwindSafe, RefUnwindSafe};
+use std::panic::RefUnwindSafe;
 use std::sync::Arc;
 use std::{cmp, fmt};
 
@@ -87,9 +87,7 @@ impl ProjectDatabase {
     ///
     /// [`set_check_mode`]: ProjectDatabase::set_check_mode
     pub fn check(&self) -> Vec<Diagnostic> {
-        let mut reporter = DummyReporter;
-        let reporter = AssertUnwindSafe(&mut reporter as &mut dyn ProgressReporter);
-        self.project().check(self, reporter)
+        self.project().check(self, &mut DummyReporter)
     }
 
     /// Checks the files in the project and its dependencies, using the given reporter.
@@ -98,7 +96,6 @@ impl ProjectDatabase {
     ///
     /// [`set_check_mode`]: ProjectDatabase::set_check_mode
     pub fn check_with_reporter(&self, reporter: &mut dyn ProgressReporter) -> Vec<Diagnostic> {
-        let reporter = AssertUnwindSafe(reporter);
         self.project().check(self, reporter)
     }
 

crates/ty_project/src/lib.rs

@@ -174,7 +174,7 @@ impl Project {
     /// This is a salsa query to prevent re-computing queries if other, unrelated
     /// settings change. For example, we don't want that changing the terminal settings
     /// invalidates any type checking queries.
-    #[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(returns(deref), heap_size=get_size2::heap_size)]
     pub fn rules(self, db: &dyn Db) -> Arc<RuleSelection> {
         self.settings(db).to_rules()
     }
@@ -228,7 +228,7 @@ impl Project {
     pub(crate) fn check(
         self,
         db: &ProjectDatabase,
-        mut reporter: AssertUnwindSafe<&mut dyn ProgressReporter>,
+        reporter: &mut dyn ProgressReporter,
     ) -> Vec<Diagnostic> {
         let project_span = tracing::debug_span!("Project::check");
         let _span = project_span.enter();
@@ -511,7 +511,7 @@ impl Project {
     }
 }
 
-#[salsa::tracked(returns(ref), heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(ref), heap_size=get_size2::heap_size)]
 pub(crate) fn check_file_impl(db: &dyn Db, file: File) -> Result<Box<[Diagnostic]>, Diagnostic> {
     let mut diagnostics: Vec<Diagnostic> = Vec::new();
 

crates/ty_project/src/metadata/settings.rs

@@ -96,7 +96,7 @@ impl Override {
 }
 
 /// Resolves the settings for a given file.
-#[salsa::tracked(returns(ref), heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(ref), heap_size=get_size2::heap_size)]
 pub(crate) fn file_settings(db: &dyn Db, file: File) -> FileSettings {
     let settings = db.project().settings(db);
 
@@ -155,7 +155,7 @@ pub(crate) fn file_settings(db: &dyn Db, file: File) -> FileSettings {
 /// This is to make Salsa happy because it requires that queries with only a single argument
 /// take a salsa-struct as argument, which isn't the case here. The `()` enables salsa's
 /// automatic interning for the arguments.
-#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(heap_size=get_size2::heap_size)]
 fn merge_overrides(db: &dyn Db, overrides: Vec<Arc<InnerOverrideOptions>>, _: ()) -> FileSettings {
     let mut overrides = overrides.into_iter().rev();
     let mut merged = (*overrides.next().unwrap()).clone();

crates/ty_python_semantic/resources/mdtest/assignment/augmented.md

@@ -13,7 +13,7 @@ reveal_type(x)  # revealed: int | float
 
 x = (1, 2)
 x += (3, 4)
-reveal_type(x)  # revealed: tuple[Literal[1], Literal[2], Literal[3], Literal[4]]
+reveal_type(x)  # revealed: tuple[Literal[1, 2, 3, 4], ...]
 ```
 
 ## Dunder methods

crates/ty_python_semantic/resources/mdtest/async.md

@@ -0,0 +1,123 @@
+# `async` / `await`
+
+## Basic
+
+```py
+async def retrieve() -> int:
+    return 42
+
+async def main():
+    result = await retrieve()
+
+    reveal_type(result)  # revealed: int
+```
+
+## Generic `async` functions
+
+```py
+from typing import TypeVar
+
+T = TypeVar("T")
+
+async def persist(x: T) -> T:
+    return x
+
+async def f(x: int):
+    result = await persist(x)
+
+    reveal_type(result)  # revealed: int
+```
+
+## Use cases
+
+### `Future`
+
+```py
+import asyncio
+import concurrent.futures
+
+def blocking_function() -> int:
+    return 42
+
+async def main():
+    loop = asyncio.get_event_loop()
+    with concurrent.futures.ThreadPoolExecutor() as pool:
+        result = await loop.run_in_executor(pool, blocking_function)
+
+        # TODO: should be `int`
+        reveal_type(result)  # revealed: Unknown
+```
+
+### `asyncio.Task`
+
+```py
+import asyncio
+
+async def f() -> int:
+    return 1
+
+async def main():
+    task = asyncio.create_task(f())
+
+    result = await task
+
+    # TODO: this should be `int`
+    reveal_type(result)  # revealed: Unknown
+```
+
+### `asyncio.gather`
+
+```py
+import asyncio
+
+async def task(name: str) -> int:
+    return len(name)
+
+async def main():
+    (a, b) = await asyncio.gather(
+        task("A"),
+        task("B"),
+    )
+
+    # TODO: these should be `int`
+    reveal_type(a)  # revealed: Unknown
+    reveal_type(b)  # revealed: Unknown
+```
+
+## Under the hood
+
+```toml
+[environment]
+python-version = "3.12"  # Use 3.12 to be able to use PEP 695 generics
+```
+
+Let's look at the example from the beginning again:
+
+```py
+async def retrieve() -> int:
+    return 42
+```
+
+When we look at the signature of this function, we see that it actually returns a `CoroutineType`:
+
+```py
+reveal_type(retrieve)  # revealed: def retrieve() -> CoroutineType[Any, Any, int]
+```
+
+The expression `await retrieve()` desugars into a call to the `__await__` dunder method on the
+`CoroutineType` object, followed by a `yield from`. Let's first see the return type of `__await__`:
+
+```py
+reveal_type(retrieve().__await__())  # revealed: Generator[Any, None, int]
+```
+
+We can see that this returns a `Generator` that yields `Any`, and eventually returns `int`. For the
+final type of the `await` expression, we retrieve that third argument of the `Generator` type:
+
+```py
+from typing import Generator
+
+def _():
+    result = yield from retrieve().__await__()
+    reveal_type(result)  # revealed: int
+```

crates/ty_python_semantic/resources/mdtest/binary/in.md

@@ -1,49 +0,0 @@
-# Static binary operations using `in`
-
-## Basic functionality
-
-This demonstrates type inference support for `<str-literal> in <tuple>`:
-
-```py
-from ty_extensions import static_assert
-
-static_assert("foo" in ("quux", "foo", "baz"))
-static_assert("foo" not in ("quux", "bar", "baz"))
-```
-
-## With variables
-
-```py
-from ty_extensions import static_assert
-
-x = ("quux", "foo", "baz")
-static_assert("foo" in x)
-
-x = ("quux", "bar", "baz")
-static_assert("foo" not in x)
-```
-
-## Statically unknown results in a `bool`
-
-```py
-def _(a: str, b: str):
-    reveal_type("foo" in (a, b))  # revealed: bool
-```
-
-## Values being unknown doesn't mean the result is unknown
-
-For example, when the types are completely disjoint:
-
-```py
-from ty_extensions import static_assert
-
-def _(a: int, b: int):
-    static_assert("foo" not in (a, b))
-```
-
-## Failure cases
-
-```py
-# We don't support byte strings.
-reveal_type(b"foo" not in (b"quux", b"foo", b"baz"))  # revealed: bool
-```

crates/ty_python_semantic/resources/mdtest/binary/tuples.md

@@ -3,14 +3,14 @@
 ## Concatenation for heterogeneous tuples
 
 ```py
-reveal_type((1, 2) + (3, 4))  # revealed: tuple[Literal[1], Literal[2], Literal[3], Literal[4]]
-reveal_type(() + (1, 2))  # revealed: tuple[Literal[1], Literal[2]]
-reveal_type((1, 2) + ())  # revealed: tuple[Literal[1], Literal[2]]
+reveal_type((1, 2) + (3, 4))  # revealed: tuple[Literal[1, 2, 3, 4], ...]
+reveal_type(() + (1, 2))  # revealed: tuple[Literal[1, 2], ...]
+reveal_type((1, 2) + ())  # revealed: tuple[Literal[1, 2], ...]
 reveal_type(() + ())  # revealed: tuple[()]
 
 def _(x: tuple[int, str], y: tuple[None, tuple[int]]):
-    reveal_type(x + y)  # revealed: tuple[int, str, None, tuple[int]]
-    reveal_type(y + x)  # revealed: tuple[None, tuple[int], int, str]
+    reveal_type(x + y)  # revealed: tuple[int | str | None | tuple[int], ...]
+    reveal_type(y + x)  # revealed: tuple[None | tuple[int] | int | str, ...]
 ```
 
 ## Concatenation for homogeneous tuples
@@ -19,10 +19,10 @@ def _(x: tuple[int, str], y: tuple[None, tuple[int]]):
 def _(x: tuple[int, ...], y: tuple[str, ...]):
     reveal_type(x + x)  # revealed: tuple[int, ...]
     reveal_type(x + y)  # revealed: tuple[int | str, ...]
-    reveal_type((1, 2) + x)  # revealed: tuple[Literal[1], Literal[2], *tuple[int, ...]]
-    reveal_type(x + (3, 4))  # revealed: tuple[*tuple[int, ...], Literal[3], Literal[4]]
-    reveal_type((1, 2) + x + (3, 4))  # revealed: tuple[Literal[1], Literal[2], *tuple[int, ...], Literal[3], Literal[4]]
-    reveal_type((1, 2) + y + (3, 4) + x)  # revealed: tuple[Literal[1], Literal[2], *tuple[int | str, ...]]
+    reveal_type((1, 2) + x)  # revealed: tuple[int, ...]
+    reveal_type(x + (3, 4))  # revealed: tuple[int, ...]
+    reveal_type((1, 2) + x + (3, 4))  # revealed: tuple[int, ...]
+    reveal_type((1, 2) + y + (3, 4) + x)  # revealed: tuple[int | str, ...]
 ```
 
 We get the same results even when we use a legacy type alias, even though this involves first
@@ -41,8 +41,8 @@ StrTuple = tuple[str, ...]
 def _(one_two: OneTwo, x: IntTuple, y: StrTuple, three_four: ThreeFour):
     reveal_type(x + x)  # revealed: tuple[int, ...]
     reveal_type(x + y)  # revealed: tuple[int | str, ...]
-    reveal_type(one_two + x)  # revealed: tuple[Literal[1], Literal[2], *tuple[int, ...]]
-    reveal_type(x + three_four)  # revealed: tuple[*tuple[int, ...], Literal[3], Literal[4]]
-    reveal_type(one_two + x + three_four)  # revealed: tuple[Literal[1], Literal[2], *tuple[int, ...], Literal[3], Literal[4]]
-    reveal_type(one_two + y + three_four + x)  # revealed: tuple[Literal[1], Literal[2], *tuple[int | str, ...]]
+    reveal_type(one_two + x)  # revealed: tuple[int, ...]
+    reveal_type(x + three_four)  # revealed: tuple[int, ...]
+    reveal_type(one_two + x + three_four)  # revealed: tuple[int, ...]
+    reveal_type(one_two + y + three_four + x)  # revealed: tuple[int | str, ...]
 ```

crates/ty_python_semantic/resources/mdtest/call/function.md

@@ -15,8 +15,7 @@ reveal_type(get_int())  # revealed: int
 async def get_int_async() -> int:
     return 42
 
-# TODO: we don't yet support `types.CoroutineType`, should be generic `Coroutine[Any, Any, int]`
-reveal_type(get_int_async())  # revealed: @Todo(generic types.CoroutineType)
+reveal_type(get_int_async())  # revealed: CoroutineType[Any, Any, int]
 ```
 
 ## Generic

crates/ty_python_semantic/resources/mdtest/call/replace.md

@@ -0,0 +1,70 @@
+# `replace`
+
+The `replace` function and the `replace` protocol were added in Python 3.13:
+<https://docs.python.org/3/whatsnew/3.13.html#copy>
+
+```toml
+[environment]
+python-version = "3.13"
+```
+
+## Basic
+
+```py
+from copy import replace
+from datetime import time
+
+t = time(12, 0, 0)
+t = replace(t, minute=30)
+
+reveal_type(t)  # revealed: time
+```
+
+## The `__replace__` protocol
+
+### Dataclasses
+
+Dataclasses support the `__replace__` protocol:
+
+```py
+from dataclasses import dataclass
+from copy import replace
+
+@dataclass
+class Point:
+    x: int
+    y: int
+
+reveal_type(Point.__replace__)  # revealed: (self: Point, *, x: int = int, y: int = int) -> Point
+```
+
+The `__replace__` method can either be called directly or through the `replace` function:
+
+```py
+a = Point(1, 2)
+
+b = a.__replace__(x=3, y=4)
+reveal_type(b)  # revealed: Point
+
+b = replace(a, x=3, y=4)
+reveal_type(b)  # revealed: Point
+```
+
+A call to `replace` does not require all keyword arguments:
+
+```py
+c = a.__replace__(y=4)
+reveal_type(c)  # revealed: Point
+
+d = replace(a, y=4)
+reveal_type(d)  # revealed: Point
+```
+
+Invalid calls to `__replace__` or `replace` will raise an error:
+
+```py
+e = a.__replace__(x="wrong")  # error: [invalid-argument-type]
+
+# TODO: this should ideally also be emit an error
+e = replace(a, x="wrong")
+```

crates/ty_python_semantic/resources/mdtest/comprehensions/basic.md

@@ -128,7 +128,7 @@ class AsyncIterable:
         return AsyncIterator()
 
 async def _():
-    # revealed: @Todo(async iterables/iterators)
+    # revealed: int
     [reveal_type(x) async for x in AsyncIterable()]
 ```
 
@@ -147,6 +147,7 @@ class Iterable:
         return Iterator()
 
 async def _():
-    # revealed: @Todo(async iterables/iterators)
+    # error: [not-iterable] "Object of type `Iterable` is not async-iterable"
+    # revealed: Unknown
     [reveal_type(x) async for x in Iterable()]
 ```

crates/ty_python_semantic/resources/mdtest/diagnostics/semantic_syntax_errors.md

@@ -27,6 +27,7 @@ If all of the comprehensions are `async`, on the other hand, the code was still
 
 ```py
 async def test():
+    # error: [not-iterable] "Object of type `range` is not async-iterable"
     return [[x async for x in elements(n)] async for n in range(3)]
 ```
 

crates/ty_python_semantic/resources/mdtest/enums.md

@@ -559,22 +559,6 @@ class Answer(Enum):
 reveal_type(enum_members(Answer))
 ```
 
-## Subclasses of `enum.Flag`
-
-```py
-from enum import Flag, auto
-
-class KeyModifier(Flag):
-    SHIFT = auto()
-    CTRL = auto()
-    ALT = auto()
-
-reveal_type(KeyModifier.SHIFT)  # revealed: Literal[KeyModifier.SHIFT]
-
-# TODO: this should be `KeyModifier`
-reveal_type(KeyModifier.SHIFT | KeyModifier.CTRL)  # revealed: Literal[KeyModifier.CTRL]
-```
-
 ## Custom enum types
 
 Enum classes can also be defined using a subclass of `enum.Enum` or any class that uses

crates/ty_python_semantic/resources/mdtest/expression/yield_and_yield_from.md

@@ -0,0 +1,130 @@
+# `yield` and `yield from`
+
+## Basic `yield` and `yield from`
+
+The type of a `yield` expression is the "send" type of the generator function. The type of a
+`yield from` expression is the return type of the inner generator:
+
+```py
+from typing import Generator
+
+def inner_generator() -> Generator[int, bytes, str]:
+    yield 1
+    yield 2
+    x = yield 3
+
+    # TODO: this should be `bytes`
+    reveal_type(x)  # revealed: @Todo(yield expressions)
+
+    return "done"
+
+def outer_generator():
+    result = yield from inner_generator()
+    reveal_type(result)  # revealed: str
+```
+
+## `yield from` with a custom iterable
+
+`yield from` can also be used with custom iterable types. In that case, the type of the `yield from`
+expression can not be determined
+
+```py
+from typing import Generator, TypeVar, Generic
+
+T = TypeVar("T")
+
+class OnceIterator(Generic[T]):
+    def __init__(self, value: T):
+        self.value = value
+        self.returned = False
+
+    def __next__(self) -> T:
+        if self.returned:
+            raise StopIteration(42)
+
+        self.returned = True
+        return self.value
+
+class Once(Generic[T]):
+    def __init__(self, value: T):
+        self.value = value
+
+    def __iter__(self) -> OnceIterator[T]:
+        return OnceIterator(self.value)
+
+for x in Once("a"):
+    reveal_type(x)  # revealed: str
+
+def generator() -> Generator:
+    result = yield from Once("a")
+
+    # At runtime, the value of `result` will be the `.value` attribute of the `StopIteration`
+    # error raised by `OnceIterator` to signal to the interpreter that the iterator has been
+    # exhausted. Here that will always be 42, but this information cannot be captured in the
+    # signature of `OnceIterator.__next__`, since exceptions lie outside the type signature.
+    # We therefore just infer `Unknown` here.
+    #
+    # If the `StopIteration` error in `OnceIterator.__next__` had been simply `raise StopIteration`
+    # (the more common case), then the `.value` attribute of the `StopIteration` instance
+    # would default to `None`.
+    reveal_type(result)  # revealed: Unknown
+```
+
+## `yield from` with a generator that return `types.GeneratorType`
+
+`types.GeneratorType` is a nominal type that implements the `typing.Generator` protocol:
+
+```py
+from types import GeneratorType
+
+def inner_generator() -> GeneratorType[int, bytes, str]:
+    yield 1
+    yield 2
+    x = yield 3
+
+    # TODO: this should be `bytes`
+    reveal_type(x)  # revealed: @Todo(yield expressions)
+
+    return "done"
+
+def outer_generator():
+    result = yield from inner_generator()
+    reveal_type(result)  # revealed: str
+```
+
+## Error cases
+
+### Non-iterable type
+
+```py
+from typing import Generator
+
+def generator() -> Generator:
+    yield from 42  # error: [not-iterable] "Object of type `Literal[42]` is not iterable"
+```
+
+### Invalid `yield` type
+
+```py
+from typing import Generator
+
+# TODO: This should be an error. Claims to yield `int`, but yields `str`.
+def invalid_generator() -> Generator[int, None, None]:
+    yield "not an int"  # This should be an `int`
+```
+
+### Invalid return type
+
+```py
+from typing import Generator
+
+# TODO: should emit an error (does not return `str`)
+def invalid_generator1() -> Generator[int, None, str]:
+    yield 1
+
+# TODO: should emit an error (does not return `int`)
+def invalid_generator2() -> Generator[int, None, None]:
+    yield 1
+
+    return "done"
+```

crates/ty_python_semantic/resources/mdtest/generics/legacy/functions.md

@@ -145,27 +145,34 @@ T = TypeVar("T")
 def takes_mixed_tuple_suffix(x: tuple[int, bytes, *tuple[str, ...], T, int]) -> T:
     return x[-2]
 
-# TODO: revealed: Literal[True]
-reveal_type(takes_mixed_tuple_suffix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Unknown
-
 def takes_mixed_tuple_prefix(x: tuple[int, T, *tuple[str, ...], bool, int]) -> T:
     return x[1]
 
-# TODO: revealed: Literal[b"foo"]
-reveal_type(takes_mixed_tuple_prefix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Unknown
+def _(x: tuple[int, bytes, *tuple[str, ...], bool, int]):
+    reveal_type(takes_mixed_tuple_suffix(x))  # revealed: bool
+    reveal_type(takes_mixed_tuple_prefix(x))  # revealed: bytes
+
+reveal_type(takes_mixed_tuple_suffix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Literal[True]
+reveal_type(takes_mixed_tuple_prefix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Literal[b"foo"]
 
 def takes_fixed_tuple(x: tuple[T, int]) -> T:
     return x[0]
 
+def _(x: tuple[str, int]):
+    reveal_type(takes_fixed_tuple(x))  # revealed: str
+
 reveal_type(takes_fixed_tuple((True, 42)))  # revealed: Literal[True]
 
 def takes_homogeneous_tuple(x: tuple[T, ...]) -> T:
     return x[0]
 
-# TODO: revealed: Literal[42]
-reveal_type(takes_homogeneous_tuple((42,)))  # revealed: Unknown
-# TODO: revealed: Literal[42, 43]
-reveal_type(takes_homogeneous_tuple((42, 43)))  # revealed: Unknown
+def _(x: tuple[str, int], y: tuple[bool, ...], z: tuple[int, str, *tuple[range, ...], bytes]):
+    reveal_type(takes_homogeneous_tuple(x))  # revealed: str | int
+    reveal_type(takes_homogeneous_tuple(y))  # revealed: bool
+    reveal_type(takes_homogeneous_tuple(z))  # revealed: int | str | range | bytes
+
+reveal_type(takes_homogeneous_tuple((42,)))  # revealed: Literal[42]
+reveal_type(takes_homogeneous_tuple((42, 43)))  # revealed: Literal[42, 43]
 ```
 
 ## Inferring a bound typevar

crates/ty_python_semantic/resources/mdtest/generics/pep695/functions.md

@@ -131,27 +131,34 @@ reveal_type(takes_in_protocol(ExplicitGenericSub[str]()))  # revealed: str
 def takes_mixed_tuple_suffix[T](x: tuple[int, bytes, *tuple[str, ...], T, int]) -> T:
     return x[-2]
 
-# TODO: revealed: Literal[True]
-reveal_type(takes_mixed_tuple_suffix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Unknown
-
 def takes_mixed_tuple_prefix[T](x: tuple[int, T, *tuple[str, ...], bool, int]) -> T:
     return x[1]
 
-# TODO: revealed: Literal[b"foo"]
-reveal_type(takes_mixed_tuple_prefix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Unknown
+def _(x: tuple[int, bytes, *tuple[str, ...], bool, int]):
+    reveal_type(takes_mixed_tuple_suffix(x))  # revealed: bool
+    reveal_type(takes_mixed_tuple_prefix(x))  # revealed: bytes
+
+reveal_type(takes_mixed_tuple_suffix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Literal[True]
+reveal_type(takes_mixed_tuple_prefix((1, b"foo", "bar", "baz", True, 42)))  # revealed: Literal[b"foo"]
 
 def takes_fixed_tuple[T](x: tuple[T, int]) -> T:
     return x[0]
 
+def _(x: tuple[str, int]):
+    reveal_type(takes_fixed_tuple(x))  # revealed: str
+
 reveal_type(takes_fixed_tuple((True, 42)))  # revealed: Literal[True]
 
 def takes_homogeneous_tuple[T](x: tuple[T, ...]) -> T:
     return x[0]
 
-# TODO: revealed: Literal[42]
-reveal_type(takes_homogeneous_tuple((42,)))  # revealed: Unknown
-# TODO: revealed: Literal[42, 43]
-reveal_type(takes_homogeneous_tuple((42, 43)))  # revealed: Unknown
+def _(x: tuple[str, int], y: tuple[bool, ...], z: tuple[int, str, *tuple[range, ...], bytes]):
+    reveal_type(takes_homogeneous_tuple(x))  # revealed: str | int
+    reveal_type(takes_homogeneous_tuple(y))  # revealed: bool
+    reveal_type(takes_homogeneous_tuple(z))  # revealed: int | str | range | bytes
+
+reveal_type(takes_homogeneous_tuple((42,)))  # revealed: Literal[42]
+reveal_type(takes_homogeneous_tuple((42, 43)))  # revealed: Literal[42, 43]
 ```
 
 ## Inferring a bound typevar

crates/ty_python_semantic/resources/mdtest/ide_support/all_members.md

@@ -1,60 +1,65 @@
 # List all members
 
+This test suite acts as a set of unit tests for our `ide_support::all_members` routine, which lists
+all members available on a given type. This routine is used for autocomplete suggestions.
+
 ## Basic functionality
 
 <!-- snapshot-diagnostics -->
 
-The `ty_extensions.all_members` function allows access to a tuple of accessible members/attributes
-on a given object. For example, all member functions of `str` are available on `"a"`:
+The `ty_extensions.all_members` and `ty_extensions.has_member` functions expose a Python-level API
+that can be used to query which attributes `ide_support::all_members` understands as being available
+on a given object. For example, all member functions of `str` are available on `"a"`. The Python API
+`all_members` returns a tuple of all available members; `has_member` returns `Literal[True]` if a
+given member is present in that tuple, and `Literal[False]` if not:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import static_assert, has_member
 
-members_of_str = all_members("a")
-
-static_assert("replace" in members_of_str)
-static_assert("startswith" in members_of_str)
-static_assert("isupper" in members_of_str)
+static_assert(has_member("a", "replace"))
+static_assert(has_member("a", "startswith"))
+static_assert(has_member("a", "isupper"))
 ```
 
 Similarly, special members such as `__add__` are also available:
 
 ```py
-static_assert("__add__" in members_of_str)
-static_assert("__gt__" in members_of_str)
+static_assert(has_member("a", "__add__"))
+static_assert(has_member("a", "__gt__"))
 ```
 
 Members of base classes are also included (these dunder methods are defined on `object`):
 
 ```py
-static_assert("__doc__" in members_of_str)
-static_assert("__repr__" in members_of_str)
+static_assert(has_member("a", "__doc__"))
+static_assert(has_member("a", "__repr__"))
 ```
 
 Non-existent members are not included:
 
 ```py
-static_assert("non_existent" not in members_of_str)
+static_assert(not has_member("a", "non_existent"))
 ```
 
-Note: The full list of all members is relatively long, but `reveal_type` can theoretically be used
-to see them all:
+The full list of all members is relatively long, but `reveal_type` can be used in combination with
+`all_members` to see them all:
 
 ```py
 from typing_extensions import reveal_type
+from ty_extensions import all_members
 
-reveal_type(members_of_str)  # error: [revealed-type]
+reveal_type(all_members("a"))  # error: [revealed-type]
 ```
 
 ## Kinds of types
 
 ### Class instances
 
-For instances of classes, `all_members` returns class members and implicit instance members of all
-classes in the MRO:
+For instances of classes, class members and implicit instance members of all superclasses are
+understood as being available:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 class Base:
     base_class_attr: int = 1
@@ -86,25 +91,23 @@ class C(Intermediate):
     def static_method() -> int:
         return 1
 
-members_of_instance = all_members(C())
+static_assert(has_member(C(), "base_class_attr"))
+static_assert(has_member(C(), "intermediate_attr"))
+static_assert(has_member(C(), "class_attr"))
 
-static_assert("base_class_attr" in members_of_instance)
-static_assert("intermediate_attr" in members_of_instance)
-static_assert("class_attr" in members_of_instance)
+static_assert(has_member(C(), "base_instance_attr"))
+static_assert(has_member(C(), "intermediate_instance_attr"))
+static_assert(has_member(C(), "instance_attr"))
 
-static_assert("base_instance_attr" in members_of_instance)
-static_assert("intermediate_instance_attr" in members_of_instance)
-static_assert("instance_attr" in members_of_instance)
+static_assert(has_member(C(), "f_base"))
+static_assert(has_member(C(), "f_intermediate"))
+static_assert(has_member(C(), "f_c"))
 
-static_assert("f_base" in members_of_instance)
-static_assert("f_intermediate" in members_of_instance)
-static_assert("f_c" in members_of_instance)
+static_assert(has_member(C(), "property_attr"))
+static_assert(has_member(C(), "class_method"))
+static_assert(has_member(C(), "static_method"))
 
-static_assert("property_attr" in members_of_instance)
-static_assert("class_method" in members_of_instance)
-static_assert("static_method" in members_of_instance)
-
-static_assert("non_existent" not in members_of_instance)
+static_assert(not has_member(C(), "non_existent"))
 ```
 
 ### Class objects
@@ -112,7 +115,7 @@ static_assert("non_existent" not in members_of_instance)
 Class-level attributes can also be accessed through the class itself:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 class Base:
     base_attr: int = 1
@@ -123,18 +126,16 @@ class C(Base):
     def f(self):
         self.instance_attr = True
 
-members_of_class = all_members(C)
+static_assert(has_member(C, "class_attr"))
+static_assert(has_member(C, "base_attr"))
 
-static_assert("class_attr" in members_of_class)
-static_assert("base_attr" in members_of_class)
-
-static_assert("non_existent" not in members_of_class)
+static_assert(not has_member(C, "non_existent"))
 ```
 
 But instance attributes can not be accessed this way:
 
 ```py
-static_assert("instance_attr" not in members_of_class)
+static_assert(not has_member(C, "instance_attr"))
 ```
 
 When a class has a metaclass, members of that metaclass (and bases of that metaclass) are also
@@ -150,16 +151,16 @@ class Meta(MetaBase):
 class D(Base, metaclass=Meta):
     class_attr = 3
 
-static_assert("meta_base_attr" in all_members(D))
-static_assert("meta_attr" in all_members(D))
-static_assert("base_attr" in all_members(D))
-static_assert("class_attr" in all_members(D))
+static_assert(has_member(D, "meta_base_attr"))
+static_assert(has_member(D, "meta_attr"))
+static_assert(has_member(D, "base_attr"))
+static_assert(has_member(D, "class_attr"))
 ```
 
 ### Generic classes
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 from typing import Generic, TypeVar
 
 T = TypeVar("T")
@@ -167,52 +168,53 @@ T = TypeVar("T")
 class C(Generic[T]):
     base_attr: T
 
-static_assert("base_attr" in all_members(C[int]))
-static_assert("base_attr" in all_members(C[int]()))
+static_assert(has_member(C[int], "base_attr"))
+static_assert(has_member(C[int](), "base_attr"))
 ```
 
 ### Other instance-like types
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 from typing_extensions import LiteralString
 
-static_assert("__xor__" in all_members(True))
-static_assert("bit_length" in all_members(1))
-static_assert("startswith" in all_members("a"))
-static_assert("__buffer__" in all_members(b"a"))
-static_assert("is_integer" in all_members(3.14))
+static_assert(has_member(True, "__xor__"))
+static_assert(has_member(1, "bit_length"))
+static_assert(has_member("a", "startswith"))
+static_assert(has_member(b"a", "__buffer__"))
+static_assert(has_member(3.14, "is_integer"))
 
 def _(literal_string: LiteralString):
-    static_assert("startswith" in all_members(literal_string))
+    static_assert(has_member(literal_string, "startswith"))
 
-static_assert("count" in all_members(("some", "tuple", 1, 2)))
+static_assert(has_member(("some", "tuple", 1, 2), "count"))
 
-static_assert("__doc__" in all_members(len))
-static_assert("__doc__" in all_members("a".startswith))
+static_assert(has_member(len, "__doc__"))
+static_assert(has_member("a".startswith, "__doc__"))
 ```
 
 ### Enums
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 from enum import Enum
 
 class Answer(Enum):
     NO = 0
     YES = 1
 
-static_assert("NO" in all_members(Answer))
-static_assert("YES" in all_members(Answer))
-static_assert("__members__" in all_members(Answer))
+static_assert(has_member(Answer, "NO"))
+static_assert(has_member(Answer, "YES"))
+static_assert(has_member(Answer, "__members__"))
 ```
 
 ### Unions
 
-For unions, `all_members` will only return members that are available on all elements of the union.
+For unions, `ide_support::all_members` only returns members that are available on all elements of
+the union.
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 class A:
     on_both: int = 1
@@ -223,20 +225,20 @@ class B:
     only_on_b: str = "b"
 
 def f(union: A | B):
-    static_assert("on_both" in all_members(union))
-    static_assert("only_on_a" not in all_members(union))
-    static_assert("only_on_b" not in all_members(union))
+    static_assert(has_member(union, "on_both"))
+    static_assert(not has_member(union, "only_on_a"))
+    static_assert(not has_member(union, "only_on_b"))
 ```
 
 ### Intersections
 
 #### Only positive types
 
-Conversely, for intersections, `all_members` will list members that are available on any of the
-elements:
+Conversely, for intersections, `ide_support::all_members` lists members that are available on any of
+the elements:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 class A:
     on_both: int = 1
@@ -249,9 +251,9 @@ class B:
 def f(intersection: object):
     if isinstance(intersection, A):
         if isinstance(intersection, B):
-            static_assert("on_both" in all_members(intersection))
-            static_assert("only_on_a" in all_members(intersection))
-            static_assert("only_on_b" in all_members(intersection))
+            static_assert(has_member(intersection, "on_both"))
+            static_assert(has_member(intersection, "only_on_a"))
+            static_assert(has_member(intersection, "only_on_b"))
 ```
 
 #### With negative types
@@ -259,7 +261,7 @@ def f(intersection: object):
 It also works when negative types are introduced:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 class A:
     on_all: int = 1
@@ -284,27 +286,27 @@ def f(intersection: object):
         if isinstance(intersection, B):
             if not isinstance(intersection, C):
                 reveal_type(intersection)  # revealed: A & B & ~C
-                static_assert("on_all" in all_members(intersection))
-                static_assert("only_on_a" in all_members(intersection))
-                static_assert("only_on_b" in all_members(intersection))
-                static_assert("only_on_c" not in all_members(intersection))
-                static_assert("only_on_ab" in all_members(intersection))
-                static_assert("only_on_ac" in all_members(intersection))
-                static_assert("only_on_bc" in all_members(intersection))
+                static_assert(has_member(intersection, "on_all"))
+                static_assert(has_member(intersection, "only_on_a"))
+                static_assert(has_member(intersection, "only_on_b"))
+                static_assert(not has_member(intersection, "only_on_c"))
+                static_assert(has_member(intersection, "only_on_ab"))
+                static_assert(has_member(intersection, "only_on_ac"))
+                static_assert(has_member(intersection, "only_on_bc"))
 ```
 
 ## Modules
 
 ### Basic support with sub-modules
 
-`all_members` can also list attributes on modules:
+`ide_support::all_members` can also list attributes on modules:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 import math
 
-static_assert("pi" in all_members(math))
-static_assert("cos" in all_members(math))
+static_assert(has_member(math, "pi"))
+static_assert(has_member(math, "cos"))
 ```
 
 This also works for submodules:
@@ -312,18 +314,18 @@ This also works for submodules:
 ```py
 import os
 
-static_assert("path" in all_members(os))
+static_assert(has_member(os, "path"))
 
 import os.path
 
-static_assert("join" in all_members(os.path))
+static_assert(has_member(os.path, "join"))
 ```
 
 Special members available on all modules are also included:
 
 ```py
-static_assert("__name__" in all_members(math))
-static_assert("__doc__" in all_members(math))
+static_assert(has_member(math, "__name__"))
+static_assert(has_member(math, "__doc__"))
 ```
 
 ### `__all__` is not respected for direct module access
@@ -331,12 +333,12 @@ static_assert("__doc__" in all_members(math))
 `foo.py`:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 import bar
 
-static_assert("lion" in all_members(bar))
-static_assert("tiger" in all_members(bar))
+static_assert(has_member(bar, "lion"))
+static_assert(has_member(bar, "tiger"))
 ```
 
 `bar.py`:
@@ -348,17 +350,17 @@ lion = 1
 tiger = 1
 ```
 
-### `__all__` is respected for glob imports
+### `__all__` is respected for `*` imports
 
 `foo.py`:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 import bar
 
-static_assert("lion" in all_members(bar))
-static_assert("tiger" not in all_members(bar))
+static_assert(has_member(bar, "lion"))
+static_assert(not has_member(bar, "tiger"))
 ```
 
 `bar.py`:
@@ -400,12 +402,12 @@ def evaluate(x: Optional[int] = None) -> int: ...
 `play.py`:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 import module
 
-static_assert("evaluate" in all_members(module))
-static_assert("Optional" not in all_members(module))
+static_assert(has_member(module, "evaluate"))
+static_assert(not has_member(module, "Optional"))
 ```
 
 ## Conditionally available members
@@ -421,9 +423,9 @@ python-version = "3.9"
 ```
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
-static_assert("bit_count" not in all_members(42))
+static_assert(not has_member(42, "bit_count"))
 ```
 
 ### 3.10
@@ -434,19 +436,19 @@ python-version = "3.10"
 ```
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
-static_assert("bit_count" in all_members(42))
+static_assert(has_member(42, "bit_count"))
 ```
 
-## Failures cases
+## Failure cases
 
 ### Dynamically added members
 
-Dynamically added members can not be accessed:
+Dynamically added members cannot be accessed:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 class C:
     static_attr = 1
@@ -460,8 +462,8 @@ class C:
 c = C()
 c.dynamic_attr = "a"
 
-static_assert("static_attr" in all_members(c))
-static_assert("dynamic_attr" not in all_members(c))
+static_assert(has_member(c, "static_attr"))
+static_assert(not has_member(c, "dynamic_attr"))
 ```
 
 ### Dataclasses
@@ -469,24 +471,24 @@ static_assert("dynamic_attr" not in all_members(c))
 So far, we do not include synthetic members of dataclasses.
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 from dataclasses import dataclass
 
 @dataclass(order=True)
 class Person:
-    name: str
     age: int
+    name: str
 
-static_assert("name" in all_members(Person))
-static_assert("age" in all_members(Person))
+static_assert(has_member(Person, "name"))
+static_assert(has_member(Person, "age"))
 
 # These are always available, since they are also defined on `object`:
-static_assert("__init__" in all_members(Person))
-static_assert("__repr__" in all_members(Person))
-static_assert("__eq__" in all_members(Person))
+static_assert(has_member(Person, "__init__"))
+static_assert(has_member(Person, "__repr__"))
+static_assert(has_member(Person, "__eq__"))
 
 # TODO: this should ideally be available:
-static_assert("__lt__" in all_members(Person))  # error: [static-assert-error]
+static_assert(has_member(Person, "__lt__"))  # error: [static-assert-error]
 ```
 
 ### Attributes not available at runtime
@@ -496,8 +498,8 @@ example, `__annotations__` does not exist on `int` at runtime, but it is availab
 on `object` in typeshed:
 
 ```py
-from ty_extensions import all_members, static_assert
+from ty_extensions import has_member, static_assert
 
 # TODO: this should ideally not be available:
-static_assert("__annotations__" not in all_members(3))  # error: [static-assert-error]
+static_assert(not has_member(3, "__annotations__"))  # error: [static-assert-error]
 ```

crates/ty_python_semantic/resources/mdtest/instance_layout_conflict.md

@@ -122,15 +122,14 @@ class A:
     __slots__ = ()
     __slots__ += ("a", "b")
 
-reveal_type(A.__slots__)  # revealed: tuple[Literal["a"], Literal["b"]]
+reveal_type(A.__slots__)  # revealed: tuple[Literal["a", "b"], ...]
 
 class B:
     __slots__ = ("c", "d")
 
-class C(  # error: [instance-layout-conflict]
-    A,
-    B,
-): ...
+# TODO: ideally this would trigger `[instance-layout-conflict]`
+# (but it's also not high-priority)
+class C(A, B): ...
 ```
 
 ## Explicitly annotated `__slots__`

crates/ty_python_semantic/resources/mdtest/loops/async_for.md

@@ -2,27 +2,6 @@
 
 Async `for` loops do not work according to the synchronous iteration protocol.
 
-## Invalid async for loop
-
-```py
-async def foo():
-    class Iterator:
-        def __next__(self) -> int:
-            return 42
-
-    class Iterable:
-        def __iter__(self) -> Iterator:
-            return Iterator()
-
-    async for x in Iterator():
-        pass
-
-    # TODO: should reveal `Unknown` because `__aiter__` is not defined
-    # revealed: @Todo(async iterables/iterators)
-    # error: [possibly-unresolved-reference]
-    reveal_type(x)
-```
-
 ## Basic async for loop
 
 ```py
@@ -35,11 +14,154 @@ async def foo():
         def __aiter__(self) -> IntAsyncIterator:
             return IntAsyncIterator()
 
-    # TODO(Alex): async iterables/iterators!
     async for x in IntAsyncIterable():
-        pass
-
-    # error: [possibly-unresolved-reference]
-    # revealed: @Todo(async iterables/iterators)
-    reveal_type(x)
+        reveal_type(x)  # revealed: int
+```
+
+## Async for loop with unpacking
+
+```py
+async def foo():
+    class AsyncIterator:
+        async def __anext__(self) -> tuple[int, str]:
+            return 42, "hello"
+
+    class AsyncIterable:
+        def __aiter__(self) -> AsyncIterator:
+            return AsyncIterator()
+
+    async for x, y in AsyncIterable():
+        reveal_type(x)  # revealed: int
+        reveal_type(y)  # revealed: str
+```
+
+## Error cases
+
+<!-- snapshot-diagnostics -->
+
+### No `__aiter__` method
+
+```py
+from typing_extensions import reveal_type
+
+class NotAsyncIterable: ...
+
+async def foo():
+    # error: [not-iterable] "Object of type `NotAsyncIterable` is not async-iterable"
+    async for x in NotAsyncIterable():
+        reveal_type(x)  # revealed: Unknown
+```
+
+### Synchronously iterable, but not asynchronously iterable
+
+```py
+from typing_extensions import reveal_type
+
+async def foo():
+    class Iterator:
+        def __next__(self) -> int:
+            return 42
+
+    class Iterable:
+        def __iter__(self) -> Iterator:
+            return Iterator()
+
+    # error: [not-iterable] "Object of type `Iterator` is not async-iterable"
+    async for x in Iterator():
+        reveal_type(x)  # revealed: Unknown
+```
+
+### No `__anext__` method
+
+```py
+from typing_extensions import reveal_type
+
+class NoAnext: ...
+
+class AsyncIterable:
+    def __aiter__(self) -> NoAnext:
+        return NoAnext()
+
+async def foo():
+    # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+    async for x in AsyncIterable():
+        reveal_type(x)  # revealed: Unknown
+```
+
+### Possibly unbound `__anext__` method
+
+```py
+from typing_extensions import reveal_type
+
+async def foo(flag: bool):
+    class PossiblyUnboundAnext:
+        if flag:
+            async def __anext__(self) -> int:
+                return 42
+
+    class AsyncIterable:
+        def __aiter__(self) -> PossiblyUnboundAnext:
+            return PossiblyUnboundAnext()
+
+    # error: [not-iterable] "Object of type `AsyncIterable` may not be async-iterable"
+    async for x in AsyncIterable():
+        reveal_type(x)  # revealed: int
+```
+
+### Possibly unbound `__aiter__` method
+
+```py
+from typing_extensions import reveal_type
+
+async def foo(flag: bool):
+    class AsyncIterable:
+        async def __anext__(self) -> int:
+            return 42
+
+    class PossiblyUnboundAiter:
+        if flag:
+            def __aiter__(self) -> AsyncIterable:
+                return AsyncIterable()
+
+    # error: "Object of type `PossiblyUnboundAiter` may not be async-iterable"
+    async for x in PossiblyUnboundAiter():
+        reveal_type(x)  # revealed: int
+```
+
+### Wrong signature for `__aiter__`
+
+```py
+from typing_extensions import reveal_type
+
+class AsyncIterator:
+    async def __anext__(self) -> int:
+        return 42
+
+class AsyncIterable:
+    def __aiter__(self, arg: int) -> AsyncIterator:  # wrong
+        return AsyncIterator()
+
+async def foo():
+    # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+    async for x in AsyncIterable():
+        reveal_type(x)  # revealed: int
+```
+
+### Wrong signature for `__anext__`
+
+```py
+from typing_extensions import reveal_type
+
+class AsyncIterator:
+    async def __anext__(self, arg: int) -> int:  # wrong
+        return 42
+
+class AsyncIterable:
+    def __aiter__(self) -> AsyncIterator:
+        return AsyncIterator()
+
+async def foo():
+    # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+    async for x in AsyncIterable():
+        reveal_type(x)  # revealed: int
 ```

crates/ty_python_semantic/resources/mdtest/narrow/assignment.md

@@ -253,7 +253,6 @@ does["not"]["exist"] = 0
 reveal_type(does["not"]["exist"])  # revealed: Unknown
 
 non_subscriptable = 1
-# error: [non-subscriptable]
 non_subscriptable[0] = 0
 # error: [non-subscriptable]
 reveal_type(non_subscriptable[0])  # revealed: Unknown

crates/ty_python_semantic/resources/mdtest/snapshots/all_members.md_-_List_all_members_-_Basic_functionality_(6b9531a70334bfad).snap

@@ -12,33 +12,32 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/ide_support/all_members.
 ## mdtest_snippet.py
 
 ```
- 1 | from ty_extensions import all_members, static_assert
+ 1 | from ty_extensions import static_assert, has_member
  2 | 
- 3 | members_of_str = all_members("a")
- 4 | 
- 5 | static_assert("replace" in members_of_str)
- 6 | static_assert("startswith" in members_of_str)
- 7 | static_assert("isupper" in members_of_str)
- 8 | static_assert("__add__" in members_of_str)
- 9 | static_assert("__gt__" in members_of_str)
-10 | static_assert("__doc__" in members_of_str)
-11 | static_assert("__repr__" in members_of_str)
-12 | static_assert("non_existent" not in members_of_str)
-13 | from typing_extensions import reveal_type
-14 | 
-15 | reveal_type(members_of_str)  # error: [revealed-type]
+ 3 | static_assert(has_member("a", "replace"))
+ 4 | static_assert(has_member("a", "startswith"))
+ 5 | static_assert(has_member("a", "isupper"))
+ 6 | static_assert(has_member("a", "__add__"))
+ 7 | static_assert(has_member("a", "__gt__"))
+ 8 | static_assert(has_member("a", "__doc__"))
+ 9 | static_assert(has_member("a", "__repr__"))
+10 | static_assert(not has_member("a", "non_existent"))
+11 | from typing_extensions import reveal_type
+12 | from ty_extensions import all_members
+13 | 
+14 | reveal_type(all_members("a"))  # error: [revealed-type]
 ```
 
 # Diagnostics
 
 ```
 info[revealed-type]: Revealed type
-  --> src/mdtest_snippet.py:15:13
+  --> src/mdtest_snippet.py:14:13
    |
-13 | from typing_extensions import reveal_type
-14 |
-15 | reveal_type(members_of_str)  # error: [revealed-type]
-   |             ^^^^^^^^^^^^^^ `tuple[Literal["__add__"], Literal["__annotations__"], Literal["__class__"], Literal["__contains__"], Literal["__delattr__"], Literal["__dict__"], Literal["__dir__"], Literal["__doc__"], Literal["__eq__"], Literal["__format__"], Literal["__ge__"], Literal["__getattribute__"], Literal["__getitem__"], Literal["__getnewargs__"], Literal["__gt__"], Literal["__hash__"], Literal["__init__"], Literal["__init_subclass__"], Literal["__iter__"], Literal["__le__"], Literal["__len__"], Literal["__lt__"], Literal["__mod__"], Literal["__module__"], Literal["__mul__"], Literal["__ne__"], Literal["__new__"], Literal["__reduce__"], Literal["__reduce_ex__"], Literal["__repr__"], Literal["__reversed__"], Literal["__rmul__"], Literal["__setattr__"], Literal["__sizeof__"], Literal["__str__"], Literal["__subclasshook__"], Literal["capitalize"], Literal["casefold"], Literal["center"], Literal["count"], Literal["encode"], Literal["endswith"], Literal["expandtabs"], Literal["find"], Literal["format"], Literal["format_map"], Literal["index"], Literal["isalnum"], Literal["isalpha"], Literal["isascii"], Literal["isdecimal"], Literal["isdigit"], Literal["isidentifier"], Literal["islower"], Literal["isnumeric"], Literal["isprintable"], Literal["isspace"], Literal["istitle"], Literal["isupper"], Literal["join"], Literal["ljust"], Literal["lower"], Literal["lstrip"], Literal["maketrans"], Literal["partition"], Literal["removeprefix"], Literal["removesuffix"], Literal["replace"], Literal["rfind"], Literal["rindex"], Literal["rjust"], Literal["rpartition"], Literal["rsplit"], Literal["rstrip"], Literal["split"], Literal["splitlines"], Literal["startswith"], Literal["strip"], Literal["swapcase"], Literal["title"], Literal["translate"], Literal["upper"], Literal["zfill"]]`
+12 | from ty_extensions import all_members
+13 |
+14 | reveal_type(all_members("a"))  # error: [revealed-type]
+   |             ^^^^^^^^^^^^^^^^ `tuple[Literal["__add__"], Literal["__annotations__"], Literal["__class__"], Literal["__contains__"], Literal["__delattr__"], Literal["__dict__"], Literal["__dir__"], Literal["__doc__"], Literal["__eq__"], Literal["__format__"], Literal["__ge__"], Literal["__getattribute__"], Literal["__getitem__"], Literal["__getnewargs__"], Literal["__gt__"], Literal["__hash__"], Literal["__init__"], Literal["__init_subclass__"], Literal["__iter__"], Literal["__le__"], Literal["__len__"], Literal["__lt__"], Literal["__mod__"], Literal["__module__"], Literal["__mul__"], Literal["__ne__"], Literal["__new__"], Literal["__reduce__"], Literal["__reduce_ex__"], Literal["__repr__"], Literal["__reversed__"], Literal["__rmul__"], Literal["__setattr__"], Literal["__sizeof__"], Literal["__str__"], Literal["__subclasshook__"], Literal["capitalize"], Literal["casefold"], Literal["center"], Literal["count"], Literal["encode"], Literal["endswith"], Literal["expandtabs"], Literal["find"], Literal["format"], Literal["format_map"], Literal["index"], Literal["isalnum"], Literal["isalpha"], Literal["isascii"], Literal["isdecimal"], Literal["isdigit"], Literal["isidentifier"], Literal["islower"], Literal["isnumeric"], Literal["isprintable"], Literal["isspace"], Literal["istitle"], Literal["isupper"], Literal["join"], Literal["ljust"], Literal["lower"], Literal["lstrip"], Literal["maketrans"], Literal["partition"], Literal["removeprefix"], Literal["removesuffix"], Literal["replace"], Literal["rfind"], Literal["rindex"], Literal["rjust"], Literal["rpartition"], Literal["rsplit"], Literal["rstrip"], Literal["split"], Literal["splitlines"], Literal["startswith"], Literal["strip"], Literal["swapcase"], Literal["title"], Literal["translate"], Literal["upper"], Literal["zfill"]]`
    |
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/async_for.md_-_Async_-_Error_cases_-_No_`__aiter__`_metho…_(4fbd80e21774cc23).snap

@@ -0,0 +1,52 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: async_for.md - Async - Error cases - No `__aiter__` method
+mdtest path: crates/ty_python_semantic/resources/mdtest/loops/async_for.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+1 | from typing_extensions import reveal_type
+2 | 
+3 | class NotAsyncIterable: ...
+4 | 
+5 | async def foo():
+6 |     # error: [not-iterable] "Object of type `NotAsyncIterable` is not async-iterable"
+7 |     async for x in NotAsyncIterable():
+8 |         reveal_type(x)  # revealed: Unknown
+```
+
+# Diagnostics
+
+```
+error[not-iterable]: Object of type `NotAsyncIterable` is not async-iterable
+ --> src/mdtest_snippet.py:7:20
+  |
+5 | async def foo():
+6 |     # error: [not-iterable] "Object of type `NotAsyncIterable` is not async-iterable"
+7 |     async for x in NotAsyncIterable():
+  |                    ^^^^^^^^^^^^^^^^^^
+8 |         reveal_type(x)  # revealed: Unknown
+  |
+info: It has no `__aiter__` method
+info: rule `not-iterable` is enabled by default
+
+```
+
+```
+info[revealed-type]: Revealed type
+ --> src/mdtest_snippet.py:8:21
+  |
+6 |     # error: [not-iterable] "Object of type `NotAsyncIterable` is not async-iterable"
+7 |     async for x in NotAsyncIterable():
+8 |         reveal_type(x)  # revealed: Unknown
+  |                     ^ `Unknown`
+  |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/async_for.md_-_Async_-_Error_cases_-_No_`__anext__`_metho…_(a0b186714127abee).snap

@@ -0,0 +1,56 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: async_for.md - Async - Error cases - No `__anext__` method
+mdtest path: crates/ty_python_semantic/resources/mdtest/loops/async_for.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | from typing_extensions import reveal_type
+ 2 | 
+ 3 | class NoAnext: ...
+ 4 | 
+ 5 | class AsyncIterable:
+ 6 |     def __aiter__(self) -> NoAnext:
+ 7 |         return NoAnext()
+ 8 | 
+ 9 | async def foo():
+10 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+11 |     async for x in AsyncIterable():
+12 |         reveal_type(x)  # revealed: Unknown
+```
+
+# Diagnostics
+
+```
+error[not-iterable]: Object of type `AsyncIterable` is not async-iterable
+  --> src/mdtest_snippet.py:11:20
+   |
+ 9 | async def foo():
+10 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+11 |     async for x in AsyncIterable():
+   |                    ^^^^^^^^^^^^^^^
+12 |         reveal_type(x)  # revealed: Unknown
+   |
+info: Its `__aiter__` method returns an object of type `NoAnext`, which has no `__anext__` method
+info: rule `not-iterable` is enabled by default
+
+```
+
+```
+info[revealed-type]: Revealed type
+  --> src/mdtest_snippet.py:12:21
+   |
+10 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+11 |     async for x in AsyncIterable():
+12 |         reveal_type(x)  # revealed: Unknown
+   |                     ^ `Unknown`
+   |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/async_for.md_-_Async_-_Error_cases_-_Possibly_unbound_`__…_(42b1d61a2b7be1b5).snap

@@ -0,0 +1,58 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: async_for.md - Async - Error cases - Possibly unbound `__aiter__` method
+mdtest path: crates/ty_python_semantic/resources/mdtest/loops/async_for.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | from typing_extensions import reveal_type
+ 2 | 
+ 3 | async def foo(flag: bool):
+ 4 |     class AsyncIterable:
+ 5 |         async def __anext__(self) -> int:
+ 6 |             return 42
+ 7 | 
+ 8 |     class PossiblyUnboundAiter:
+ 9 |         if flag:
+10 |             def __aiter__(self) -> AsyncIterable:
+11 |                 return AsyncIterable()
+12 | 
+13 |     # error: "Object of type `PossiblyUnboundAiter` may not be async-iterable"
+14 |     async for x in PossiblyUnboundAiter():
+15 |         reveal_type(x)  # revealed: int
+```
+
+# Diagnostics
+
+```
+error[not-iterable]: Object of type `PossiblyUnboundAiter` may not be async-iterable
+  --> src/mdtest_snippet.py:14:20
+   |
+13 |     # error: "Object of type `PossiblyUnboundAiter` may not be async-iterable"
+14 |     async for x in PossiblyUnboundAiter():
+   |                    ^^^^^^^^^^^^^^^^^^^^^^
+15 |         reveal_type(x)  # revealed: int
+   |
+info: Its `__aiter__` attribute (with type `bound method PossiblyUnboundAiter.__aiter__() -> AsyncIterable`) may not be callable
+info: rule `not-iterable` is enabled by default
+
+```
+
+```
+info[revealed-type]: Revealed type
+  --> src/mdtest_snippet.py:15:21
+   |
+13 |     # error: "Object of type `PossiblyUnboundAiter` may not be async-iterable"
+14 |     async for x in PossiblyUnboundAiter():
+15 |         reveal_type(x)  # revealed: int
+   |                     ^ `int`
+   |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/async_for.md_-_Async_-_Error_cases_-_Possibly_unbound_`__…_(74ad2f945cad6ed8).snap

@@ -0,0 +1,58 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: async_for.md - Async - Error cases - Possibly unbound `__anext__` method
+mdtest path: crates/ty_python_semantic/resources/mdtest/loops/async_for.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | from typing_extensions import reveal_type
+ 2 | 
+ 3 | async def foo(flag: bool):
+ 4 |     class PossiblyUnboundAnext:
+ 5 |         if flag:
+ 6 |             async def __anext__(self) -> int:
+ 7 |                 return 42
+ 8 | 
+ 9 |     class AsyncIterable:
+10 |         def __aiter__(self) -> PossiblyUnboundAnext:
+11 |             return PossiblyUnboundAnext()
+12 | 
+13 |     # error: [not-iterable] "Object of type `AsyncIterable` may not be async-iterable"
+14 |     async for x in AsyncIterable():
+15 |         reveal_type(x)  # revealed: int
+```
+
+# Diagnostics
+
+```
+error[not-iterable]: Object of type `AsyncIterable` may not be async-iterable
+  --> src/mdtest_snippet.py:14:20
+   |
+13 |     # error: [not-iterable] "Object of type `AsyncIterable` may not be async-iterable"
+14 |     async for x in AsyncIterable():
+   |                    ^^^^^^^^^^^^^^^
+15 |         reveal_type(x)  # revealed: int
+   |
+info: Its `__aiter__` method returns an object of type `PossiblyUnboundAnext`, which may not have a `__anext__` method
+info: rule `not-iterable` is enabled by default
+
+```
+
+```
+info[revealed-type]: Revealed type
+  --> src/mdtest_snippet.py:15:21
+   |
+13 |     # error: [not-iterable] "Object of type `AsyncIterable` may not be async-iterable"
+14 |     async for x in AsyncIterable():
+15 |         reveal_type(x)  # revealed: int
+   |                     ^ `int`
+   |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/async_for.md_-_Async_-_Error_cases_-_Synchronously_iterab…_(80fa705b1c61d982).snap

@@ -0,0 +1,57 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: async_for.md - Async - Error cases - Synchronously iterable, but not asynchronously iterable
+mdtest path: crates/ty_python_semantic/resources/mdtest/loops/async_for.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | from typing_extensions import reveal_type
+ 2 | 
+ 3 | async def foo():
+ 4 |     class Iterator:
+ 5 |         def __next__(self) -> int:
+ 6 |             return 42
+ 7 | 
+ 8 |     class Iterable:
+ 9 |         def __iter__(self) -> Iterator:
+10 |             return Iterator()
+11 | 
+12 |     # error: [not-iterable] "Object of type `Iterator` is not async-iterable"
+13 |     async for x in Iterator():
+14 |         reveal_type(x)  # revealed: Unknown
+```
+
+# Diagnostics
+
+```
+error[not-iterable]: Object of type `Iterator` is not async-iterable
+  --> src/mdtest_snippet.py:13:20
+   |
+12 |     # error: [not-iterable] "Object of type `Iterator` is not async-iterable"
+13 |     async for x in Iterator():
+   |                    ^^^^^^^^^^
+14 |         reveal_type(x)  # revealed: Unknown
+   |
+info: It has no `__aiter__` method
+info: rule `not-iterable` is enabled by default
+
+```
+
+```
+info[revealed-type]: Revealed type
+  --> src/mdtest_snippet.py:14:21
+   |
+12 |     # error: [not-iterable] "Object of type `Iterator` is not async-iterable"
+13 |     async for x in Iterator():
+14 |         reveal_type(x)  # revealed: Unknown
+   |                     ^ `Unknown`
+   |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/async_for.md_-_Async_-_Error_cases_-_Wrong_signature_for_…_(b614724363eec343).snap

@@ -0,0 +1,59 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: async_for.md - Async - Error cases - Wrong signature for `__anext__`
+mdtest path: crates/ty_python_semantic/resources/mdtest/loops/async_for.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | from typing_extensions import reveal_type
+ 2 | 
+ 3 | class AsyncIterator:
+ 4 |     async def __anext__(self, arg: int) -> int:  # wrong
+ 5 |         return 42
+ 6 | 
+ 7 | class AsyncIterable:
+ 8 |     def __aiter__(self) -> AsyncIterator:
+ 9 |         return AsyncIterator()
+10 | 
+11 | async def foo():
+12 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+13 |     async for x in AsyncIterable():
+14 |         reveal_type(x)  # revealed: int
+```
+
+# Diagnostics
+
+```
+error[not-iterable]: Object of type `AsyncIterable` is not async-iterable
+  --> src/mdtest_snippet.py:13:20
+   |
+11 | async def foo():
+12 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+13 |     async for x in AsyncIterable():
+   |                    ^^^^^^^^^^^^^^^
+14 |         reveal_type(x)  # revealed: int
+   |
+info: Its `__aiter__` method returns an object of type `AsyncIterator`, which has an invalid `__anext__` method
+info: Expected signature for `__anext__` is `def __anext__(self): ...`
+info: rule `not-iterable` is enabled by default
+
+```
+
+```
+info[revealed-type]: Revealed type
+  --> src/mdtest_snippet.py:14:21
+   |
+12 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+13 |     async for x in AsyncIterable():
+14 |         reveal_type(x)  # revealed: int
+   |                     ^ `int`
+   |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/async_for.md_-_Async_-_Error_cases_-_Wrong_signature_for_…_(e1f3e9275d0a367).snap

@@ -0,0 +1,59 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: async_for.md - Async - Error cases - Wrong signature for `__aiter__`
+mdtest path: crates/ty_python_semantic/resources/mdtest/loops/async_for.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+ 1 | from typing_extensions import reveal_type
+ 2 | 
+ 3 | class AsyncIterator:
+ 4 |     async def __anext__(self) -> int:
+ 5 |         return 42
+ 6 | 
+ 7 | class AsyncIterable:
+ 8 |     def __aiter__(self, arg: int) -> AsyncIterator:  # wrong
+ 9 |         return AsyncIterator()
+10 | 
+11 | async def foo():
+12 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+13 |     async for x in AsyncIterable():
+14 |         reveal_type(x)  # revealed: int
+```
+
+# Diagnostics
+
+```
+error[not-iterable]: Object of type `AsyncIterable` is not async-iterable
+  --> src/mdtest_snippet.py:13:20
+   |
+11 | async def foo():
+12 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+13 |     async for x in AsyncIterable():
+   |                    ^^^^^^^^^^^^^^^
+14 |         reveal_type(x)  # revealed: int
+   |
+info: Its `__aiter__` method has an invalid signature
+info: Expected signature `def __aiter__(self): ...`
+info: rule `not-iterable` is enabled by default
+
+```
+
+```
+info[revealed-type]: Revealed type
+  --> src/mdtest_snippet.py:14:21
+   |
+12 |     # error: [not-iterable] "Object of type `AsyncIterable` is not async-iterable"
+13 |     async for x in AsyncIterable():
+14 |         reveal_type(x)  # revealed: int
+   |                     ^ `int`
+   |
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_Possibly_invalid_`__…_(c626bde8651b643a).snap

@@ -60,7 +60,7 @@ error[not-iterable]: Object of type `Iterable1` may not be iterable
 29 |         reveal_type(x)  # revealed: int | str
    |
 info: Its `__iter__` method returns an object of type `Iterator1`, which may have an invalid `__next__` method
-info: Expected signature for `__next__` is `def __next__(self): ...`)
+info: Expected signature for `__next__` is `def __next__(self): ...`
 info: rule `not-iterable` is enabled by default
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/semantic_syntax_erro…_-_Semantic_syntax_erro…_-_`async`_comprehensio…_-_Python_3.10_(96aa8ec77d46553d).snap

@@ -19,14 +19,15 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/semantic_syn
  5 |     # error: 19 [invalid-syntax] "cannot use an asynchronous comprehension inside of a synchronous comprehension on Python 3.10 (syntax was added in 3.11)"
  6 |     return {n: [x async for x in elements(n)] for n in range(3)}
  7 | async def test():
- 8 |     return [[x async for x in elements(n)] async for n in range(3)]
- 9 | async def f():
-10 |     [x for x in [1]] and [x async for x in elements(1)]
-11 | 
-12 | async def f():
-13 |     def g():
-14 |         pass
-15 |     [x async for x in elements(1)]
+ 8 |     # error: [not-iterable] "Object of type `range` is not async-iterable"
+ 9 |     return [[x async for x in elements(n)] async for n in range(3)]
+10 | async def f():
+11 |     [x for x in [1]] and [x async for x in elements(1)]
+12 | 
+13 | async def f():
+14 |     def g():
+15 |         pass
+16 |     [x async for x in elements(1)]
 ```
 
 # Diagnostics
@@ -40,7 +41,23 @@ error[invalid-syntax]
 6 |     return {n: [x async for x in elements(n)] for n in range(3)}
   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot use an asynchronous comprehension inside of a synchronous comprehension on Python 3.10 (syntax was added in 3.11)
 7 | async def test():
-8 |     return [[x async for x in elements(n)] async for n in range(3)]
+8 |     # error: [not-iterable] "Object of type `range` is not async-iterable"
   |
 
 ```
+
+```
+error[not-iterable]: Object of type `range` is not async-iterable
+  --> src/mdtest_snippet.py:9:59
+   |
+ 7 | async def test():
+ 8 |     # error: [not-iterable] "Object of type `range` is not async-iterable"
+ 9 |     return [[x async for x in elements(n)] async for n in range(3)]
+   |                                                           ^^^^^^^^
+10 | async def f():
+11 |     [x for x in [1]] and [x async for x in elements(1)]
+   |
+info: It has no `__aiter__` method
+info: rule `not-iterable` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/subscript/instance.md

@@ -1,6 +1,6 @@
 # Instance subscript
 
-## Getitem unbound
+## `__getitem__` unbound
 
 ```py
 class NotSubscriptable: ...
@@ -8,7 +8,7 @@ class NotSubscriptable: ...
 a = NotSubscriptable()[0]  # error: "Cannot subscript object of type `NotSubscriptable` with no `__getitem__` method"
 ```
 
-## Getitem not callable
+## `__getitem__` not callable
 
 ```py
 class NotSubscriptable:
@@ -18,7 +18,7 @@ class NotSubscriptable:
 a = NotSubscriptable()[0]
 ```
 
-## Valid getitem
+## Valid `__getitem__`
 
 ```py
 class Identity:
@@ -28,7 +28,7 @@ class Identity:
 reveal_type(Identity()[0])  # revealed: int
 ```
 
-## Getitem union
+## `__getitem__` union
 
 ```py
 def _(flag: bool):
@@ -42,3 +42,14 @@ def _(flag: bool):
 
     reveal_type(Identity()[0])  # revealed: int | str
 ```
+
+## `__setitem__` with no `__getitem__`
+
+```py
+class NoGetitem:
+    def __setitem__(self, index: int, value: int) -> None:
+        pass
+
+a = NoGetitem()
+a[0] = 0
+```

crates/ty_python_semantic/resources/mdtest/subscript/tuple.md

@@ -2,6 +2,11 @@
 
 ## Indexing
 
+```toml
+[environment]
+python-version = "3.11"
+```
+
 ```py
 t = (1, "a", "b")
 
@@ -20,6 +25,148 @@ b = t[-4]  # error: [index-out-of-bounds]
 reveal_type(b)  # revealed: Unknown
 ```
 
+Precise types for index operations are also inferred for tuple subclasses:
+
+```py
+class I0: ...
+class I1: ...
+class I2: ...
+class I3: ...
+class I5: ...
+class HeterogeneousSubclass0(tuple[()]): ...
+
+# revealed: Overload[(self, index: SupportsIndex, /) -> Never, (self, index: slice[Any, Any, Any], /) -> tuple[()]]
+reveal_type(HeterogeneousSubclass0.__getitem__)
+
+def f0(h0: HeterogeneousSubclass0, i: int):
+    reveal_type(h0[0])  # revealed: Never
+    reveal_type(h0[1])  # revealed: Never
+    reveal_type(h0[-1])  # revealed: Never
+    reveal_type(h0[i])  # revealed: Never
+
+class HeterogeneousSubclass1(tuple[I0]): ...
+
+# revealed: Overload[(self, index: SupportsIndex, /) -> I0, (self, index: slice[Any, Any, Any], /) -> tuple[I0, ...]]
+reveal_type(HeterogeneousSubclass1.__getitem__)
+
+def f0(h1: HeterogeneousSubclass1, i: int):
+    reveal_type(h1[0])  # revealed: I0
+    reveal_type(h1[1])  # revealed: I0
+    reveal_type(h1[-1])  # revealed: I0
+    reveal_type(h1[i])  # revealed: I0
+
+# Element at index 2 is deliberately the same as the element at index 1,
+# to illustrate that the `__getitem__` overloads for these two indices are combined
+class HeterogeneousSubclass4(tuple[I0, I1, I0, I3]): ...
+
+# revealed: Overload[(self, index: Literal[-4, -2, 0, 2], /) -> I0, (self, index: Literal[-3, 1], /) -> I1, (self, index: Literal[-1, 3], /) -> I3, (self, index: SupportsIndex, /) -> I0 | I1 | I3, (self, index: slice[Any, Any, Any], /) -> tuple[I0 | I1 | I3, ...]]
+reveal_type(HeterogeneousSubclass4.__getitem__)
+
+def f(h4: HeterogeneousSubclass4, i: int):
+    reveal_type(h4[0])  # revealed: I0
+    reveal_type(h4[1])  # revealed: I1
+    reveal_type(h4[2])  # revealed: I0
+    reveal_type(h4[3])  # revealed: I3
+    reveal_type(h4[-1])  # revealed: I3
+    reveal_type(h4[-2])  # revealed: I0
+    reveal_type(h4[-3])  # revealed: I1
+    reveal_type(h4[-4])  # revealed: I0
+    reveal_type(h4[i])  # revealed: I0 | I1 | I3
+
+class MixedSubclass(tuple[I0, *tuple[I1, ...], I2, I3, I2, I5]): ...
+
+# revealed: Overload[(self, index: Literal[0], /) -> I0, (self, index: Literal[-5], /) -> I1 | I0, (self, index: Literal[-1], /) -> I5, (self, index: Literal[1], /) -> I1 | I2, (self, index: Literal[-4, -2], /) -> I2, (self, index: Literal[2, 3], /) -> I1 | I2 | I3, (self, index: Literal[-3], /) -> I3, (self, index: Literal[4], /) -> I1 | I2 | I3 | I5, (self, index: SupportsIndex, /) -> I0 | I1 | I2 | I3 | I5, (self, index: slice[Any, Any, Any], /) -> tuple[I0 | I1 | I2 | I3 | I5, ...]]
+reveal_type(MixedSubclass.__getitem__)
+
+def g(m: MixedSubclass, i: int):
+    reveal_type(m[0])  # revealed: I0
+    reveal_type(m[1])  # revealed: I1 | I2
+    reveal_type(m[2])  # revealed: I1 | I2 | I3
+    reveal_type(m[3])  # revealed: I1 | I2 | I3
+    reveal_type(m[4])  # revealed: I1 | I2 | I3 | I5
+
+    reveal_type(m[-1])  # revealed: I5
+    reveal_type(m[-2])  # revealed: I2
+    reveal_type(m[-3])  # revealed: I3
+    reveal_type(m[-4])  # revealed: I2
+    reveal_type(m[-5])  # revealed: I1 | I0
+
+    reveal_type(m[i])  # revealed: I0 | I1 | I2 | I3 | I5
+
+    # Ideally we would not include `I0` in the unions for these,
+    # but it's not possible to do this using only synthesized overloads.
+    reveal_type(m[5])  # revealed: I0 | I1 | I2 | I3 | I5
+    reveal_type(m[10])  # revealed: I0 | I1 | I2 | I3 | I5
+
+    # Similarly, ideally these would just be `I0` | I1`,
+    # but achieving that with only synthesized overloads wouldn't be possible
+    reveal_type(m[-6])  # revealed: I0 | I1 | I2 | I3 | I5
+    reveal_type(m[-10])  # revealed: I0 | I1 | I2 | I3 | I5
+
+class MixedSubclass2(tuple[I0, I1, *tuple[I2, ...], I3]): ...
+
+# revealed: Overload[(self, index: Literal[0], /) -> I0, (self, index: Literal[-2], /) -> I2 | I1, (self, index: Literal[1], /) -> I1, (self, index: Literal[-3], /) -> I2 | I1 | I0, (self, index: Literal[-1], /) -> I3, (self, index: Literal[2], /) -> I2 | I3, (self, index: SupportsIndex, /) -> I0 | I1 | I2 | I3, (self, index: slice[Any, Any, Any], /) -> tuple[I0 | I1 | I2 | I3, ...]]
+reveal_type(MixedSubclass2.__getitem__)
+
+def g(m: MixedSubclass2, i: int):
+    reveal_type(m[0])  # revealed: I0
+    reveal_type(m[1])  # revealed: I1
+    reveal_type(m[2])  # revealed: I2 | I3
+
+    # Ideally this would just be `I2 | I3`,
+    # but that's not possible to achieve with synthesized overloads
+    reveal_type(m[3])  # revealed: I0 | I1 | I2 | I3
+
+    reveal_type(m[-1])  # revealed: I3
+    reveal_type(m[-2])  # revealed: I2 | I1
+    reveal_type(m[-3])  # revealed: I2 | I1 | I0
+
+    # Ideally this would just be `I2 | I1 | I0`,
+    # but that's not possible to achieve with synthesized overloads
+    reveal_type(m[-4])  # revealed: I0 | I1 | I2 | I3
+```
+
+The stdlib API `os.stat` is a commonly used API that returns an instance of a tuple subclass
+(`os.stat_result`), and therefore provides a good integration test for tuple subclasses.
+
+```py
+import os
+import stat
+
+reveal_type(os.stat("my_file.txt"))  # revealed: stat_result
+reveal_type(os.stat("my_file.txt")[stat.ST_MODE])  # revealed: int
+reveal_type(os.stat("my_file.txt")[stat.ST_ATIME])  # revealed: int | float
+
+# revealed: tuple[<class 'stat_result'>, <class 'structseq[int | float]'>, <class 'tuple[int, int, int, int, int, int, int, int | float, int | float, int | float]'>, <class 'Sequence[int | float]'>, <class 'Reversible[int | float]'>, <class 'Collection[int | float]'>, <class 'Iterable[int | float]'>, <class 'Container[int | float]'>, typing.Protocol, typing.Generic, <class 'object'>]
+reveal_type(os.stat_result.__mro__)
+
+# There are no specific overloads for the `float` elements in `os.stat_result`,
+# because the fallback `(self, index: SupportsIndex, /) -> int | float` overload
+# gives the right result for those elements in the tuple, and we aim to synthesize
+# the minimum number of overloads for any given tuple
+#
+# revealed: Overload[(self, index: Literal[-10, -9, -8, -7, -6, -5, -4, 0, 1, 2, 3, 4, 5, 6], /) -> int, (self, index: SupportsIndex, /) -> int | float, (self, index: slice[Any, Any, Any], /) -> tuple[int | float, ...]]
+reveal_type(os.stat_result.__getitem__)
+```
+
+Because of the synthesized `__getitem__` overloads we synthesize for tuples and tuple subclasses,
+tuples are naturally understood as being subtypes of protocols that have precise return types from
+`__getitem__` method members:
+
+```py
+from typing import Protocol, Literal
+from ty_extensions import static_assert, is_subtype_of
+
+class IntFromZeroSubscript(Protocol):
+    def __getitem__(self, index: Literal[0], /) -> int: ...
+
+static_assert(is_subtype_of(tuple[int, str], IntFromZeroSubscript))
+
+class TupleSubclass(tuple[int, str]): ...
+
+static_assert(is_subtype_of(TupleSubclass, IntFromZeroSubscript))
+```
+
 ## Slices
 
 ```py
@@ -93,9 +240,7 @@ def homogeneous(t: tuple[str, ...]) -> None:
     reveal_type(t[-3])  # revealed: str
     reveal_type(t[-4])  # revealed: str
 
-def mixed(s: tuple[str, ...]) -> None:
-    t = (1, 2, 3) + s + (8, 9, 10)
-
+def mixed(t: tuple[Literal[1], Literal[2], Literal[3], *tuple[str, ...], Literal[8], Literal[9], Literal[10]]) -> None:
     reveal_type(t[0])  # revealed: Literal[1]
     reveal_type(t[1])  # revealed: Literal[2]
     reveal_type(t[2])  # revealed: Literal[3]

crates/ty_python_semantic/resources/mdtest/with/async.md

@@ -17,5 +17,80 @@ class Manager:
 
 async def test():
     async with Manager() as f:
-        reveal_type(f)  # revealed: @Todo(async `with` statement)
+        reveal_type(f)  # revealed: Target
+```
+
+## Multiple targets
+
+```py
+class Manager:
+    async def __aenter__(self) -> tuple[int, str]:
+        return 42, "hello"
+
+    async def __aexit__(self, exc_type, exc_value, traceback): ...
+
+async def test():
+    async with Manager() as (x, y):
+        reveal_type(x)  # revealed: int
+        reveal_type(y)  # revealed: str
+```
+
+## `@asynccontextmanager`
+
+```py
+from contextlib import asynccontextmanager
+from typing import AsyncGenerator
+
+class Session: ...
+
+@asynccontextmanager
+async def connect() -> AsyncGenerator[Session]:
+    yield Session()
+
+# TODO: this should be `() -> _AsyncGeneratorContextManager[Session, None]`
+reveal_type(connect)  # revealed: (...) -> _AsyncGeneratorContextManager[Unknown, None]
+
+async def main():
+    async with connect() as session:
+        # TODO: should be `Session`
+        reveal_type(session)  # revealed: Unknown
+```
+
+## `asyncio.timeout`
+
+```toml
+[environment]
+python-version = "3.11"
+```
+
+```py
+import asyncio
+
+async def long_running_task():
+    await asyncio.sleep(5)
+
+async def main():
+    async with asyncio.timeout(1):
+        await long_running_task()
+```
+
+## `asyncio.TaskGroup`
+
+```toml
+[environment]
+python-version = "3.11"
+```
+
+```py
+import asyncio
+
+async def long_running_task():
+    await asyncio.sleep(5)
+
+async def main():
+    async with asyncio.TaskGroup() as tg:
+        # TODO: should be `TaskGroup`
+        reveal_type(tg)  # revealed: Unknown
+
+        tg.create_task(long_running_task())
 ```

crates/ty_python_semantic/resources/primer/bad.txt

@@ -10,6 +10,8 @@ jax  # too many iterations
 mypy # too many iterations (self-recursive type alias)
 packaging  # too many iterations
 pandas  # slow (9s)
+pandas-stubs  # panics on versions of pandas-stubs newer than https://github.com/pandas-dev/pandas-stubs/commit/bf1221eb7ea0e582c30fe233d1f4f5713fce376b
+              # Panicked at crates/ty_python_semantic/src/types/type_ordering.rs:207:13 when checking `/tmp/mypy_primer/projects/pandas-stubs/tests/test_indexes.py`: `internal error: entered unreachable code: our type representation does not permit nested unions`
 pandera  # too many iterations
 pip  # vendors packaging, see above
 pylint  # cycle panics (self-recursive type alias)

crates/ty_python_semantic/resources/primer/good.txt

@@ -69,7 +69,6 @@ openlibrary
 operator
 optuna
 paasta
-pandas-stubs
 paroxython
 parso
 pegen

crates/ty_python_semantic/src/dunder_all.rs

@@ -26,7 +26,7 @@ fn dunder_all_names_cycle_initial(_db: &dyn Db, _file: File) -> Option<FxHashSet
 
 /// Returns a set of names in the `__all__` variable for `file`, [`None`] if it is not defined or
 /// if it contains invalid elements.
-#[salsa::tracked(returns(as_ref), cycle_fn=dunder_all_names_cycle_recover, cycle_initial=dunder_all_names_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(as_ref), cycle_fn=dunder_all_names_cycle_recover, cycle_initial=dunder_all_names_cycle_initial, heap_size=get_size2::heap_size)]
 pub(crate) fn dunder_all_names(db: &dyn Db, file: File) -> Option<FxHashSet<Name>> {
     let _span = tracing::trace_span!("dunder_all_names", file=?file.path(db)).entered();
 

crates/ty_python_semantic/src/module_resolver/import-resolution-diagram.dot

@@ -0,0 +1,209 @@
+// This is a Dot representation of a flow diagram meant to describe Python's
+// import resolution rules. This particular diagram starts with one particular
+// search path and one particular module name. (Typical import resolution
+// implementation will try multiple search paths.)
+//
+// This diagram also assumes that stubs are allowed. The ty implementation
+// of import resolution makes this a configurable parameter, but it should
+// be straight-forward to adapt this flow diagram to one where no stubs
+// are allowed. (i.e., Remove `.pyi` checks and remove the `package-stubs`
+// handling.)
+//
+// This flow diagram exists to act as a sort of specification. At the time
+// of writing (2025-07-29), it was written to capture the implementation of
+// resolving a *particular* module name. We wanted to add another code path for
+// *listing* available module names. Since code reuse is somewhat difficult
+// between these two access patterns, I wrote this flow diagram as a way of 1)
+// learning how module resolution works and 2) to provide a "source of truth"
+// that we can compare implementations to.
+//
+// To convert this file into an actual image, you'll need the `dot` program
+// (which is typically part of a `graphviz` package in a Linux distro):
+//
+//     dot -Tsvg import-resolution-diagram.dot > import-resolution-diagram.svg
+//
+// And then view it in a web browser (or some other svg viewer):
+//
+//     firefox ./import-resolution-diagram.svg
+//
+// [Dot]: https://graphviz.org/doc/info/lang.html
+
+digraph python_import_resolution {
+    labelloc="t";
+    label=<
+        <b>Python import resolution flow diagram for a single module name in a single "search path"</b>
+        <br/>(assumes that the module name is valid and that stubs are allowed)
+    >;
+
+    // These are the final affirmative states we can end up in. A
+    // module is a regular `foo.py` file module. A package is a
+    // directory containing an `__init__.py`. A namespace package is a
+    // directory that does *not* contain an `__init__.py`.
+    module [label="Single-file Module",peripheries=2];
+    package [label="Package",peripheries=2];
+    namespace_package [label="Namespace Package",peripheries=2];
+    not_found [label="Module Not Found",peripheries=2];
+
+    // The final states are wrapped in a subgraph with invisible edges
+    // to convince GraphViz to give a more human digestible rendering.
+    // Without this, the nodes are scattered every which way and the
+    // flow diagram is pretty hard to follow. This encourages (but does
+    // not guarantee) GraphViz to put these nodes "close" together, and
+    // this generally gets us something grokable.
+    subgraph final {
+        rank = same;
+        module -> package -> namespace_package -> not_found [style=invis];
+    }
+
+    START [label=<<b>START</b>>];
+    START -> non_shadowable;
+
+    non_shadowable [label=<
+        Is the search path not the standard library and<br/>
+        the module name is `types` or some other built-in?
+    >];
+    non_shadowable -> not_found [label="Yes"];
+    non_shadowable -> stub_package_check [label="No"];
+
+    stub_package_check [label=<
+        Is the search path in the standard library?
+    >];
+    stub_package_check -> stub_package_set [label="No"];
+    stub_package_check -> determine_parent_kind [label="Yes"];
+
+    stub_package_set [label=<
+        Set `module_name` to `{top-package}-stubs.{rest}`
+    >];
+    stub_package_set -> determine_parent_kind;
+
+    determine_parent_kind [label=<
+        Does every parent package of `module_name`<br/>
+        correspond to a directory that contains an<br/>
+        `__init__.py` or an `__init__.pyi`?
+    >];
+    determine_parent_kind -> regular_parent_std [label="Yes"];
+    determine_parent_kind -> namespace_parent_regular_check [label="No"];
+
+    regular_parent_std [label=<
+        Does the search path correspond to the standard library?
+    >];
+    regular_parent_std -> resolved_parent_package [label="No"];
+    regular_parent_std -> regular_parent_typeshed_check [label="Yes"];
+
+    regular_parent_typeshed_check [label=<
+        Does every parent package of<br/>
+        `module_name` exist on the configured<br/>
+        Python version according to <br/>
+        typeshed's VERSIONS file?
+    >];
+    regular_parent_typeshed_check -> resolved_parent_package [label="Yes"];
+    regular_parent_typeshed_check -> bail [label="No"];
+
+    namespace_parent_regular_check [label=<
+        Is the direct parent package<br/>
+        a directory that contains<br/>
+        an `__init__.py` or `__init__.pyi`?
+    >];
+    namespace_parent_regular_check -> bail [label="Yes"];
+    namespace_parent_regular_check -> namespace_parent_std [label="No"];
+
+    namespace_parent_std [label=<
+        Does the search path correspond to the standard library?
+    >];
+    namespace_parent_std -> namespace_parent_module_check [label="No"];
+    namespace_parent_std -> namespace_parent_typeshed_check [label="Yes"];
+
+    namespace_parent_typeshed_check [label=<
+        Does the direct parent package of<br/>
+        `module_name` exist on the configured<br/>
+        Python version according to <br/>
+        typeshed's VERSIONS file?
+    >];
+    namespace_parent_typeshed_check -> namespace_parent_module_check [label="Yes"];
+    namespace_parent_typeshed_check -> bail [label="No"];
+
+    namespace_parent_module_check [label=<
+        Does the direct parent package<br/>
+        have a sibling file with the same<br/>
+        basename and a `py` or `pyi` extension?<br/>
+    >];
+    namespace_parent_module_check -> bail [label="Yes"];
+    namespace_parent_module_check -> namespace_parent_above [label="No"];
+
+    namespace_parent_above [label=<
+        Is every parent above the direct<br/>
+        parent package a normal package or<br/>
+        otherwise satisfy the previous two<br/>
+        namespace package requirements?
+    >];
+    namespace_parent_above -> bail [label="No"];
+    namespace_parent_above -> resolved_parent_package [label="Yes"];
+
+    resolved_parent_package [label=<
+        After replacing `.` with `/` in module name,<br/>
+        does `{path}/__init__.py` or `{path}/__init__.pyi` exist?
+    >];
+    resolved_parent_package -> package [label="Yes"];
+    resolved_parent_package -> maybe_module [label="No"];
+
+    maybe_module [label=<
+        Does `{path}.py` or `{path}.pyi` exist?
+    >];
+    maybe_module -> maybe_module_std [label="Yes"];
+    maybe_module -> maybe_namespace [label="No"];
+
+    maybe_module_std [label=<
+        Does the search path correspond to the standard library?
+    >];
+    maybe_module_std -> module [label="No"];
+    maybe_module_std -> maybe_module_typeshed_check [label="Yes"];
+
+    maybe_module_typeshed_check [label=<
+        Does the module corresponding to `{path}`<br/>
+        exist on the configured<br/>
+        Python version according to <br/>
+        typeshed's VERSIONS file?
+    >];
+    maybe_module_typeshed_check -> module [label="Yes"];
+    maybe_module_typeshed_check -> maybe_namespace [label="No"];
+
+    // N.B. In the actual implementation, this check is
+    // only done when the search path *isn't* the standard
+    // library. That's because typeshed doesn't use namespace
+    // packages, so this (and the typeshed VERSIONS check)
+    // can all be skipped as an optimization. But the flow
+    // diagram still represents this because this could in
+    // theory change and optimizations really should be the
+    // domain of the implementation, not the spec.
+    maybe_namespace [label=<
+        Is `{path}` a directory?
+    >];
+    maybe_namespace -> maybe_namespace_std [label="Yes"];
+    maybe_namespace -> bail [label="No"];
+
+    maybe_namespace_std [label=<
+        Does the search path correspond to the standard library?
+    >];
+    maybe_namespace_std -> namespace_package [label="No"];
+    maybe_namespace_std -> maybe_namespace_typeshed_check [label="Yes"];
+
+    maybe_namespace_typeshed_check [label=<
+        Does the module corresponding to `{path}`<br/>
+        exist on the configured<br/>
+        Python version according to <br/>
+        typeshed's VERSIONS file?
+    >];
+    maybe_namespace_typeshed_check -> namespace_package [label="Yes"];
+    maybe_namespace_typeshed_check -> bail [label="No"];
+
+    bail [label=<
+        Is `module_name` set to a stub package candidate?
+    >];
+    bail -> not_found [label="No"];
+    bail -> retry [label="Yes"];
+
+    retry [label=<
+        Reset `module_name` to original
+    >];
+    retry -> determine_parent_kind;
+}

crates/ty_python_semantic/src/module_resolver/import-resolution-diagram.svg

@@ -0,0 +1,468 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
+ "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<!-- Generated by graphviz version 13.0.1 (0)
+ -->
+<!-- Title: python_import_resolution Pages: 1 -->
+<svg width="1837pt" height="2172pt"
+ viewBox="0.00 0.00 1837.00 2172.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
+<g id="graph0" class="graph" transform="scale(1 1) rotate(0) translate(4 2167.68)">
+<title>python_import_resolution</title>
+<polygon fill="white" stroke="none" points="-4,4 -4,-2167.68 1832.95,-2167.68 1832.95,4 -4,4"/>
+<text xml:space="preserve" text-anchor="start" x="524.85" y="-2147.38" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;</text>
+<text xml:space="preserve" text-anchor="start" x="560.85" y="-2147.38" font-family="Times,serif" font-weight="bold" font-size="14.00">Python import resolution flow diagram for a single module name in a single &quot;search path&quot;</text>
+<text xml:space="preserve" text-anchor="start" x="1268.1" y="-2147.38" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;</text>
+<text xml:space="preserve" text-anchor="start" x="663.23" y="-2133.38" font-family="Times,serif" font-size="14.00">(assumes that the module name is valid and that stubs are allowed) &#160;&#160;&#160;</text>
+<!-- module -->
+<g id="node1" class="node">
+<title>module</title>
+<ellipse fill="none" stroke="black" cx="105.71" cy="-22" rx="101.71" ry="18"/>
+<ellipse fill="none" stroke="black" cx="105.71" cy="-22" rx="105.71" ry="22"/>
+<text xml:space="preserve" text-anchor="middle" x="105.71" y="-17.32" font-family="Times,serif" font-size="14.00">Single&#45;file Module</text>
+</g>
+<!-- package -->
+<g id="node2" class="node">
+<title>package</title>
+<ellipse fill="none" stroke="black" cx="302.71" cy="-22" rx="52.26" ry="18"/>
+<ellipse fill="none" stroke="black" cx="302.71" cy="-22" rx="56.26" ry="22"/>
+<text xml:space="preserve" text-anchor="middle" x="302.71" y="-17.32" font-family="Times,serif" font-size="14.00">Package</text>
+</g>
+<!-- module&#45;&gt;package -->
+<!-- namespace_package -->
+<g id="node3" class="node">
+<title>namespace_package</title>
+<ellipse fill="none" stroke="black" cx="529.71" cy="-22" rx="113.29" ry="18"/>
+<ellipse fill="none" stroke="black" cx="529.71" cy="-22" rx="117.29" ry="22"/>
+<text xml:space="preserve" text-anchor="middle" x="529.71" y="-17.32" font-family="Times,serif" font-size="14.00">Namespace Package</text>
+</g>
+<!-- package&#45;&gt;namespace_package -->
+<!-- not_found -->
+<g id="node4" class="node">
+<title>not_found</title>
+<ellipse fill="none" stroke="black" cx="1227.71" cy="-22" rx="104.35" ry="18"/>
+<ellipse fill="none" stroke="black" cx="1227.71" cy="-22" rx="108.35" ry="22"/>
+<text xml:space="preserve" text-anchor="middle" x="1227.71" y="-17.32" font-family="Times,serif" font-size="14.00">Module Not Found</text>
+</g>
+<!-- namespace_package&#45;&gt;not_found -->
+<!-- START -->
+<g id="node5" class="node">
+<title>START</title>
+<ellipse fill="none" stroke="black" cx="1521.71" cy="-2109.68" rx="47.53" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="1495.84" y="-2106" font-family="Times,serif" font-weight="bold" font-size="14.00">START</text>
+</g>
+<!-- non_shadowable -->
+<g id="node6" class="node">
+<title>non_shadowable</title>
+<ellipse fill="none" stroke="black" cx="1521.71" cy="-2024.63" rx="307.24" ry="30.05"/>
+<text xml:space="preserve" text-anchor="start" x="1335.71" y="-2028.58" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Is the search path not the standard library and</text>
+<text xml:space="preserve" text-anchor="start" x="1312.46" y="-2011.33" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;the module name is `types` or some other built&#45;in? &#160;&#160;&#160;</text>
+</g>
+<!-- START&#45;&gt;non_shadowable -->
+<g id="edge4" class="edge">
+<title>START&#45;&gt;non_shadowable</title>
+<path fill="none" stroke="black" d="M1521.71,-2091.47C1521.71,-2084.14 1521.71,-2075.24 1521.71,-2066.39"/>
+<polygon fill="black" stroke="black" points="1525.21,-2066.43 1521.71,-2056.43 1518.21,-2066.43 1525.21,-2066.43"/>
+</g>
+<!-- non_shadowable&#45;&gt;not_found -->
+<g id="edge5" class="edge">
+<title>non_shadowable&#45;&gt;not_found</title>
+<path fill="none" stroke="black" d="M1654.8,-1997.15C1687.69,-1982.48 1713.71,-1959.69 1713.71,-1924.32 1713.71,-1924.32 1713.71,-1924.32 1713.71,-114.25 1713.71,-76.19 1480.54,-47.08 1337.21,-32.77"/>
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+</g>
+<!-- stub_package_check -->
+<g id="node7" class="node">
+<title>stub_package_check</title>
+<ellipse fill="none" stroke="black" cx="1329.71" cy="-1923.32" rx="261.65" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="1151.21" y="-1918.65" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Is the search path in the standard library? &#160;&#160;&#160;</text>
+</g>
+<!-- non_shadowable&#45;&gt;stub_package_check -->
+<g id="edge6" class="edge">
+<title>non_shadowable&#45;&gt;stub_package_check</title>
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+<text xml:space="preserve" text-anchor="middle" x="1435.84" y="-1963.27" font-family="Times,serif" font-size="14.00">No</text>
+</g>
+<!-- stub_package_set -->
+<g id="node8" class="node">
+<title>stub_package_set</title>
+<ellipse fill="none" stroke="black" cx="1329.71" cy="-1834.07" rx="312.68" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="1114.84" y="-1829.4" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Set `module_name` to `{top&#45;package}&#45;stubs.{rest}` &#160;&#160;&#160;</text>
+</g>
+<!-- stub_package_check&#45;&gt;stub_package_set -->
+<g id="edge7" class="edge">
+<title>stub_package_check&#45;&gt;stub_package_set</title>
+<path fill="none" stroke="black" d="M1329.71,-1905.09C1329.71,-1893.26 1329.71,-1877.28 1329.71,-1863.57"/>
+<polygon fill="black" stroke="black" points="1333.21,-1863.79 1329.71,-1853.79 1326.21,-1863.79 1333.21,-1863.79"/>
+<text xml:space="preserve" text-anchor="middle" x="1339.84" y="-1874.02" font-family="Times,serif" font-size="14.00">No</text>
+</g>
+<!-- determine_parent_kind -->
+<g id="node9" class="node">
+<title>determine_parent_kind</title>
+<ellipse fill="none" stroke="black" cx="974.71" cy="-1736.83" rx="269.05" ry="42.25"/>
+<text xml:space="preserve" text-anchor="start" x="792.46" y="-1749.4" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does every parent package of `module_name`</text>
+<text xml:space="preserve" text-anchor="start" x="805.96" y="-1732.15" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;correspond to a directory that contains an</text>
+<text xml:space="preserve" text-anchor="start" x="832.59" y="-1714.9" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;`__init__.py` or an `__init__.pyi`? &#160;&#160;&#160;</text>
+</g>
+<!-- stub_package_check&#45;&gt;determine_parent_kind -->
+<g id="edge8" class="edge">
+<title>stub_package_check&#45;&gt;determine_parent_kind</title>
+<path fill="none" stroke="black" d="M1171.52,-1908.62C1092.86,-1898.32 1009.21,-1880.88 983.71,-1852.07 969.18,-1835.66 965.49,-1812.2 966.01,-1790.82"/>
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+</g>
+<!-- stub_package_set&#45;&gt;determine_parent_kind -->
+<g id="edge9" class="edge">
+<title>stub_package_set&#45;&gt;determine_parent_kind</title>
+<path fill="none" stroke="black" d="M1266.25,-1816.05C1225.47,-1805.11 1170.77,-1790.43 1119.77,-1776.75"/>
+<polygon fill="black" stroke="black" points="1120.98,-1773.45 1110.41,-1774.23 1119.17,-1780.21 1120.98,-1773.45"/>
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+<!-- regular_parent_std -->
+<g id="node10" class="node">
+<title>regular_parent_std</title>
+<ellipse fill="none" stroke="black" cx="617.71" cy="-1197.73" rx="337.41" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="385.21" y="-1193.06" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the search path correspond to the standard library? &#160;&#160;&#160;</text>
+</g>
+<!-- determine_parent_kind&#45;&gt;regular_parent_std -->
+<g id="edge10" class="edge">
+<title>determine_parent_kind&#45;&gt;regular_parent_std</title>
+<path fill="none" stroke="black" d="M832.87,-1700.59C787.46,-1680.2 748.71,-1648.59 748.71,-1600.08 748.71,-1600.08 748.71,-1600.08 748.71,-1358.88 748.71,-1299.61 694.28,-1250.21 655.59,-1222.58"/>
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+</g>
+<!-- namespace_parent_regular_check -->
+<g id="node11" class="node">
+<title>namespace_parent_regular_check</title>
+<ellipse fill="none" stroke="black" cx="1296.71" cy="-1599.08" rx="212.31" ry="42.25"/>
+<text xml:space="preserve" text-anchor="start" x="1177.84" y="-1611.65" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Is the direct parent package</text>
+<text xml:space="preserve" text-anchor="start" x="1190.59" y="-1594.4" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;a directory that contains</text>
+<text xml:space="preserve" text-anchor="start" x="1154.59" y="-1577.15" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;an `__init__.py` or `__init__.pyi`? &#160;&#160;&#160;</text>
+</g>
+<!-- determine_parent_kind&#45;&gt;namespace_parent_regular_check -->
+<g id="edge11" class="edge">
+<title>determine_parent_kind&#45;&gt;namespace_parent_regular_check</title>
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+<!-- resolved_parent_package -->
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+<title>resolved_parent_package</title>
+<ellipse fill="none" stroke="black" cx="512.71" cy="-897.84" rx="328.45" ry="30.05"/>
+<text xml:space="preserve" text-anchor="start" x="339.09" y="-901.79" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;After replacing `.` with `/` in module name,</text>
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+</g>
+<!-- regular_parent_std&#45;&gt;resolved_parent_package -->
+<g id="edge12" class="edge">
+<title>regular_parent_std&#45;&gt;resolved_parent_package</title>
+<path fill="none" stroke="black" d="M568.87,-1179.57C530.36,-1163.14 479.31,-1134.25 455.46,-1090.04 432.49,-1047.44 440.98,-1027.32 455.46,-981.14 460.37,-965.51 469.41,-950.24 478.88,-937.19"/>
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+</g>
+<!-- regular_parent_typeshed_check -->
+<g id="node13" class="node">
+<title>regular_parent_typeshed_check</title>
+<ellipse fill="none" stroke="black" cx="719.71" cy="-1035.59" rx="235.11" ry="54.45"/>
+<text xml:space="preserve" text-anchor="start" x="595.59" y="-1056.79" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does every parent package of</text>
+<text xml:space="preserve" text-anchor="start" x="561.46" y="-1039.54" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;`module_name` exist on the configured</text>
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+</g>
+<!-- regular_parent_std&#45;&gt;regular_parent_typeshed_check -->
+<g id="edge13" class="edge">
+<title>regular_parent_std&#45;&gt;regular_parent_typeshed_check</title>
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+</g>
+<!-- bail -->
+<g id="node14" class="node">
+<title>bail</title>
+<ellipse fill="none" stroke="black" cx="1222.71" cy="-115.25" rx="306.9" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="1011.96" y="-110.58" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Is `module_name` set to a stub package candidate? &#160;&#160;&#160;</text>
+</g>
+<!-- namespace_parent_regular_check&#45;&gt;bail -->
+<g id="edge16" class="edge">
+<title>namespace_parent_regular_check&#45;&gt;bail</title>
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+<!-- namespace_parent_std -->
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+<title>namespace_parent_std</title>
+<ellipse fill="none" stroke="black" cx="1296.71" cy="-1485.58" rx="337.41" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="1064.21" y="-1480.9" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the search path correspond to the standard library? &#160;&#160;&#160;</text>
+</g>
+<!-- namespace_parent_regular_check&#45;&gt;namespace_parent_std -->
+<g id="edge17" class="edge">
+<title>namespace_parent_regular_check&#45;&gt;namespace_parent_std</title>
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+<!-- resolved_parent_package&#45;&gt;package -->
+<g id="edge26" class="edge">
+<title>resolved_parent_package&#45;&gt;package</title>
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+</g>
+<!-- maybe_module -->
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+<title>maybe_module</title>
+<ellipse fill="none" stroke="black" cx="512.71" cy="-796.54" rx="249.55" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="342.84" y="-791.86" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does `{path}.py` or `{path}.pyi` exist? &#160;&#160;&#160;</text>
+</g>
+<!-- resolved_parent_package&#45;&gt;maybe_module -->
+<g id="edge27" class="edge">
+<title>resolved_parent_package&#45;&gt;maybe_module</title>
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+<!-- regular_parent_typeshed_check&#45;&gt;resolved_parent_package -->
+<g id="edge14" class="edge">
+<title>regular_parent_typeshed_check&#45;&gt;resolved_parent_package</title>
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+<!-- regular_parent_typeshed_check&#45;&gt;bail -->
+<g id="edge15" class="edge">
+<title>regular_parent_typeshed_check&#45;&gt;bail</title>
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+</g>
+<!-- bail&#45;&gt;not_found -->
+<g id="edge40" class="edge">
+<title>bail&#45;&gt;not_found</title>
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+<text xml:space="preserve" text-anchor="middle" x="1235.64" y="-65.95" font-family="Times,serif" font-size="14.00">No</text>
+</g>
+<!-- retry -->
+<g id="node25" class="node">
+<title>retry</title>
+<ellipse fill="none" stroke="black" cx="887.71" cy="-22" rx="213.78" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="743.34" y="-17.32" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Reset `module_name` to original &#160;&#160;&#160;</text>
+</g>
+<!-- bail&#45;&gt;retry -->
+<g id="edge41" class="edge">
+<title>bail&#45;&gt;retry</title>
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+<polygon fill="black" stroke="black" points="960.92,-39.31 950.35,-40.06 959.08,-46.07 960.92,-39.31"/>
+<text xml:space="preserve" text-anchor="middle" x="1097.22" y="-65.95" font-family="Times,serif" font-size="14.00">Yes</text>
+</g>
+<!-- namespace_parent_module_check -->
+<g id="node16" class="node">
+<title>namespace_parent_module_check</title>
+<ellipse fill="none" stroke="black" cx="1358.71" cy="-1197.73" rx="242.54" ry="54.45"/>
+<text xml:space="preserve" text-anchor="start" x="1228.59" y="-1218.93" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the direct parent package</text>
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+<text xml:space="preserve" text-anchor="start" x="1195.21" y="-1184.43" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;basename and a `py` or `pyi` extension?</text>
+<text xml:space="preserve" text-anchor="start" x="1349.71" y="-1167.18" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;</text>
+</g>
+<!-- namespace_parent_std&#45;&gt;namespace_parent_module_check -->
+<g id="edge18" class="edge">
+<title>namespace_parent_std&#45;&gt;namespace_parent_module_check</title>
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+</g>
+<!-- namespace_parent_typeshed_check -->
+<g id="node17" class="node">
+<title>namespace_parent_typeshed_check</title>
+<ellipse fill="none" stroke="black" cx="1194.71" cy="-1359.88" rx="235.11" ry="54.45"/>
+<text xml:space="preserve" text-anchor="start" x="1055.59" y="-1381.08" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the direct parent package of</text>
+<text xml:space="preserve" text-anchor="start" x="1036.46" y="-1363.83" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;`module_name` exist on the configured</text>
+<text xml:space="preserve" text-anchor="start" x="1074.34" y="-1346.58" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Python version according to </text>
+<text xml:space="preserve" text-anchor="start" x="1070.96" y="-1329.33" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;typeshed&#39;s VERSIONS file? &#160;&#160;&#160;</text>
+</g>
+<!-- namespace_parent_std&#45;&gt;namespace_parent_typeshed_check -->
+<g id="edge19" class="edge">
+<title>namespace_parent_std&#45;&gt;namespace_parent_typeshed_check</title>
+<path fill="none" stroke="black" d="M1282.32,-1467.12C1272.54,-1455.26 1258.98,-1438.81 1245.44,-1422.4"/>
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+</g>
+<!-- namespace_parent_module_check&#45;&gt;bail -->
+<g id="edge22" class="edge">
+<title>namespace_parent_module_check&#45;&gt;bail</title>
+<path fill="none" stroke="black" d="M1480.33,-1150.23C1524.93,-1124.65 1564.71,-1087.55 1564.71,-1036.59 1564.71,-1036.59 1564.71,-1036.59 1564.71,-239.95 1564.71,-190.04 1434.32,-154.61 1334.56,-134.8"/>
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+</g>
+<!-- namespace_parent_above -->
+<g id="node18" class="node">
+<title>namespace_parent_above</title>
+<ellipse fill="none" stroke="black" cx="1309.71" cy="-1035.59" rx="227.16" ry="54.45"/>
+<text xml:space="preserve" text-anchor="start" x="1176.96" y="-1056.79" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Is every parent above the direct</text>
+<text xml:space="preserve" text-anchor="start" x="1161.59" y="-1039.54" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;parent package a normal package or</text>
+<text xml:space="preserve" text-anchor="start" x="1168.34" y="-1022.29" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;otherwise satisfy the previous two</text>
+<text xml:space="preserve" text-anchor="start" x="1157.09" y="-1005.04" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;namespace package requirements? &#160;&#160;&#160;</text>
+</g>
+<!-- namespace_parent_module_check&#45;&gt;namespace_parent_above -->
+<g id="edge23" class="edge">
+<title>namespace_parent_module_check&#45;&gt;namespace_parent_above</title>
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+<text xml:space="preserve" text-anchor="middle" x="1345.81" y="-1111.99" font-family="Times,serif" font-size="14.00">No</text>
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+<!-- namespace_parent_typeshed_check&#45;&gt;bail -->
+<g id="edge21" class="edge">
+<title>namespace_parent_typeshed_check&#45;&gt;bail</title>
+<path fill="none" stroke="black" d="M1117.34,-1308.13C1084.97,-1280.37 1054.71,-1242.68 1054.71,-1198.73 1054.71,-1198.73 1054.71,-1198.73 1054.71,-239.95 1054.71,-188.54 1106.36,-156.11 1152.39,-137.42"/>
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+<!-- namespace_parent_typeshed_check&#45;&gt;namespace_parent_module_check -->
+<g id="edge20" class="edge">
+<title>namespace_parent_typeshed_check&#45;&gt;namespace_parent_module_check</title>
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+</g>
+<!-- namespace_parent_above&#45;&gt;resolved_parent_package -->
+<g id="edge25" class="edge">
+<title>namespace_parent_above&#45;&gt;resolved_parent_package</title>
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+</g>
+<!-- namespace_parent_above&#45;&gt;bail -->
+<g id="edge24" class="edge">
+<title>namespace_parent_above&#45;&gt;bail</title>
+<path fill="none" stroke="black" d="M1283.87,-981.05C1274.29,-956.57 1265.71,-926.84 1265.71,-898.84 1265.71,-898.84 1265.71,-898.84 1265.71,-239.95 1265.71,-205.29 1250.47,-168.04 1238.13,-143.58"/>
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+<text xml:space="preserve" text-anchor="middle" x="1275.84" y="-576.92" font-family="Times,serif" font-size="14.00">No</text>
+</g>
+<!-- maybe_module_std -->
+<g id="node20" class="node">
+<title>maybe_module_std</title>
+<ellipse fill="none" stroke="black" cx="455.71" cy="-707.29" rx="337.41" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="223.21" y="-702.61" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the search path correspond to the standard library? &#160;&#160;&#160;</text>
+</g>
+<!-- maybe_module&#45;&gt;maybe_module_std -->
+<g id="edge28" class="edge">
+<title>maybe_module&#45;&gt;maybe_module_std</title>
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+<polygon fill="black" stroke="black" points="476.18,-733.22 467.78,-726.76 470.32,-737.04 476.18,-733.22"/>
+<text xml:space="preserve" text-anchor="middle" x="501.32" y="-747.24" font-family="Times,serif" font-size="14.00">Yes</text>
+</g>
+<!-- maybe_namespace -->
+<g id="node21" class="node">
+<title>maybe_namespace</title>
+<ellipse fill="none" stroke="black" cx="641.71" cy="-455.89" rx="169.06" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="529.21" y="-451.22" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Is `{path}` a directory? &#160;&#160;&#160;</text>
+</g>
+<!-- maybe_module&#45;&gt;maybe_namespace -->
+<g id="edge29" class="edge">
+<title>maybe_module&#45;&gt;maybe_namespace</title>
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+</g>
+<!-- maybe_module_std&#45;&gt;module -->
+<g id="edge30" class="edge">
+<title>maybe_module_std&#45;&gt;module</title>
+<path fill="none" stroke="black" d="M303.75,-690.81C262.51,-680.5 220.31,-663.61 187.71,-636.04 104.95,-566.04 90.71,-520.66 90.71,-412.27 90.71,-412.27 90.71,-412.27 90.71,-114.25 90.71,-94.55 94.16,-72.78 97.75,-55.44"/>
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+</g>
+<!-- maybe_module_typeshed_check -->
+<g id="node22" class="node">
+<title>maybe_module_typeshed_check</title>
+<ellipse fill="none" stroke="black" cx="455.71" cy="-581.59" rx="258.98" ry="54.45"/>
+<text xml:space="preserve" text-anchor="start" x="280.59" y="-602.79" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the module corresponding to `{path}`</text>
+<text xml:space="preserve" text-anchor="start" x="355.59" y="-585.54" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;exist on the configured</text>
+<text xml:space="preserve" text-anchor="start" x="335.34" y="-568.29" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Python version according to </text>
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+</g>
+<!-- maybe_module_std&#45;&gt;maybe_module_typeshed_check -->
+<g id="edge31" class="edge">
+<title>maybe_module_std&#45;&gt;maybe_module_typeshed_check</title>
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+<text xml:space="preserve" text-anchor="middle" x="467.71" y="-657.99" font-family="Times,serif" font-size="14.00">Yes</text>
+</g>
+<!-- maybe_namespace&#45;&gt;bail -->
+<g id="edge35" class="edge">
+<title>maybe_namespace&#45;&gt;bail</title>
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+</g>
+<!-- maybe_namespace_std -->
+<g id="node23" class="node">
+<title>maybe_namespace_std</title>
+<ellipse fill="none" stroke="black" cx="541.71" cy="-366.64" rx="337.41" ry="18"/>
+<text xml:space="preserve" text-anchor="start" x="309.21" y="-361.97" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the search path correspond to the standard library? &#160;&#160;&#160;</text>
+</g>
+<!-- maybe_namespace&#45;&gt;maybe_namespace_std -->
+<g id="edge34" class="edge">
+<title>maybe_namespace&#45;&gt;maybe_namespace_std</title>
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+<title>maybe_module_typeshed_check&#45;&gt;module</title>
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+</g>
+<!-- maybe_module_typeshed_check&#45;&gt;maybe_namespace -->
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+<title>maybe_module_typeshed_check&#45;&gt;maybe_namespace</title>
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+</g>
+<!-- maybe_namespace_std&#45;&gt;namespace_package -->
+<g id="edge36" class="edge">
+<title>maybe_namespace_std&#45;&gt;namespace_package</title>
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+<!-- maybe_namespace_typeshed_check -->
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+<title>maybe_namespace_typeshed_check</title>
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+<text xml:space="preserve" text-anchor="start" x="444.59" y="-262.15" font-family="Times,serif" font-size="14.00"> &#160;&#160;&#160;&#160;&#160;&#160;&#160;Does the module corresponding to `{path}`</text>
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+</g>
+<!-- maybe_namespace_std&#45;&gt;maybe_namespace_typeshed_check -->
+<g id="edge37" class="edge">
+<title>maybe_namespace_std&#45;&gt;maybe_namespace_typeshed_check</title>
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+</g>
+<!-- maybe_namespace_typeshed_check&#45;&gt;namespace_package -->
+<g id="edge38" class="edge">
+<title>maybe_namespace_typeshed_check&#45;&gt;namespace_package</title>
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+<g id="edge39" class="edge">
+<title>maybe_namespace_typeshed_check&#45;&gt;bail</title>
+<path fill="none" stroke="black" d="M739.84,-192.37C782.94,-177.02 832.31,-161.37 878.46,-151.25 920.17,-142.11 965.24,-135.35 1008.61,-130.35"/>
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+</g>
+<!-- retry&#45;&gt;determine_parent_kind -->
+<g id="edge42" class="edge">
+<title>retry&#45;&gt;determine_parent_kind</title>
+<path fill="none" stroke="black" d="M889.55,-40.44C892.13,-62.4 897.56,-101.12 906.71,-133.25 931.39,-219.83 982.71,-230.99 982.71,-321.02 982.71,-1117.66 982.71,-1117.66 982.71,-1117.66 982.71,-1262.68 931.71,-1294.93 931.71,-1439.95 931.71,-1600.08 931.71,-1600.08 931.71,-1600.08 931.71,-1628.61 940.46,-1659.01 950.06,-1683.79"/>
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+</g>
+</g>
+</svg>

crates/ty_python_semantic/src/module_resolver/resolver.rs

@@ -1,3 +1,13 @@
+/*!
+This module principally provides two routines for resolving a particular module
+name to a `Module`: [`resolve_module`] and [`resolve_real_module`]. You'll
+usually want the former, unless you're certain you want to forbid stubs, in
+which case, use the latter.
+
+For implementors, see `import-resolution-diagram.svg` for a flow diagram that
+specifies ty's implementation of Python's import resolution algorithm.
+*/
+
 use std::borrow::Cow;
 use std::fmt;
 use std::iter::FusedIterator;
@@ -51,8 +61,8 @@ impl ModuleResolveMode {
 ///
 /// This query should not be called directly. Instead, use [`resolve_module`]. It only exists
 /// because Salsa requires the module name to be an ingredient.
-#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
-pub(crate) fn resolve_module_query<'db>(
+#[salsa::tracked(heap_size=get_size2::heap_size)]
+fn resolve_module_query<'db>(
     db: &'db dyn Db,
     module_name: ModuleNameIngredient<'db>,
 ) -> Option<Module<'db>> {
@@ -108,7 +118,7 @@ pub(crate) fn path_to_module<'db>(db: &'db dyn Db, path: &FilePath) -> Option<Mo
 /// Resolves the module for the file with the given id.
 ///
 /// Returns `None` if the file is not a module locatable via any of the known search paths.
-#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(heap_size=get_size2::heap_size)]
 pub(crate) fn file_to_module(db: &dyn Db, file: File) -> Option<Module<'_>> {
     let _span = tracing::trace_span!("file_to_module", ?file).entered();
 
@@ -149,8 +159,9 @@ pub(crate) fn search_paths(db: &dyn Db) -> SearchPathIterator {
 
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct SearchPaths {
-    /// Search paths that have been statically determined purely from reading ty's configuration settings.
-    /// These shouldn't ever change unless the config settings themselves change.
+    /// Search paths that have been statically determined purely from reading
+    /// ty's configuration settings. These shouldn't ever change unless the
+    /// config settings themselves change.
     static_paths: Vec<SearchPath>,
 
     /// site-packages paths are not included in the above field:
@@ -193,19 +204,19 @@ impl SearchPaths {
 
         for path in extra_paths {
             let path = canonicalize(path, system);
-            tracing::debug!("Adding extra search-path '{path}'");
+            tracing::debug!("Adding extra search-path `{path}`");
 
             static_paths.push(SearchPath::extra(system, path)?);
         }
 
         for src_root in src_roots {
-            tracing::debug!("Adding first-party search path '{src_root}'");
+            tracing::debug!("Adding first-party search path `{src_root}`");
             static_paths.push(SearchPath::first_party(system, src_root.to_path_buf())?);
         }
 
         let (typeshed_versions, stdlib_path) = if let Some(typeshed) = typeshed {
             let typeshed = canonicalize(typeshed, system);
-            tracing::debug!("Adding custom-stdlib search path '{typeshed}'");
+            tracing::debug!("Adding custom-stdlib search path `{typeshed}`");
 
             let versions_path = typeshed.join("stdlib/VERSIONS");
 
@@ -234,17 +245,22 @@ impl SearchPaths {
         let mut site_packages: Vec<_> = Vec::with_capacity(site_packages_paths.len());
 
         for path in site_packages_paths {
-            tracing::debug!("Adding site-packages search path '{path}'");
+            tracing::debug!("Adding site-packages search path `{path}`");
             site_packages.push(SearchPath::site_packages(system, path.clone())?);
         }
 
-        // TODO vendor typeshed's third-party stubs as well as the stdlib and fallback to them as a final step
-
-        // Filter out module resolution paths that point to the same directory on disk (the same invariant maintained by [`sys.path` at runtime]).
-        // (Paths may, however, *overlap* -- e.g. you could have both `src/` and `src/foo`
-        // as module resolution paths simultaneously.)
+        // TODO vendor typeshed's third-party stubs as well as the stdlib and
+        // fallback to them as a final step?
         //
-        // This code doesn't use an `IndexSet` because the key is the system path and not the search root.
+        // See: <https://github.com/astral-sh/ruff/pull/19620#discussion_r2240609135>
+
+        // Filter out module resolution paths that point to the same directory
+        // on disk (the same invariant maintained by [`sys.path` at runtime]).
+        // (Paths may, however, *overlap* -- e.g. you could have both `src/`
+        // and `src/foo` as module resolution paths simultaneously.)
+        //
+        // This code doesn't use an `IndexSet` because the key is the system
+        // path and not the search root.
         //
         // [`sys.path` at runtime]: https://docs.python.org/3/library/site.html#module-site
         let mut seen_paths = FxHashSet::with_capacity_and_hasher(static_paths.len(), FxBuildHasher);
@@ -306,7 +322,7 @@ impl SearchPaths {
 /// The editable-install search paths for the first `site-packages` directory
 /// should come between the two `site-packages` directories when it comes to
 /// module-resolution priority.
-#[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(deref), heap_size=get_size2::heap_size)]
 pub(crate) fn dynamic_resolution_paths(db: &dyn Db) -> Vec<SearchPath> {
     tracing::debug!("Resolving dynamic module resolution paths");
 
@@ -521,7 +537,7 @@ impl<'db> Iterator for PthFileIterator<'db> {
             let contents = match system.read_to_string(&path) {
                 Ok(contents) => contents,
                 Err(error) => {
-                    tracing::warn!("Failed to read .pth file '{path}': {error}");
+                    tracing::warn!("Failed to read .pth file `{path}`: {error}");
                     continue;
                 }
             };
@@ -582,7 +598,8 @@ fn resolve_name(db: &dyn Db, name: &ModuleName, mode: ModuleResolveMode) -> Opti
                 Ok((package_kind, ResolvedName::FileModule(module))) => {
                     if package_kind.is_root() && module.kind.is_module() {
                         tracing::trace!(
-                            "Search path '{search_path} contains a module named `{stub_name}` but a standalone module isn't a valid stub."
+                            "Search path `{search_path}` contains a module \
+                             named `{stub_name}` but a standalone module isn't a valid stub."
                         );
                     } else {
                         return Some(ResolvedName::FileModule(module));
@@ -593,12 +610,12 @@ fn resolve_name(db: &dyn Db, name: &ModuleName, mode: ModuleResolveMode) -> Opti
                 }
                 Err(PackageKind::Root) => {
                     tracing::trace!(
-                        "Search path '{search_path}' contains no stub package named `{stub_name}`."
+                        "Search path `{search_path}` contains no stub package named `{stub_name}`."
                     );
                 }
                 Err(PackageKind::Regular) => {
                     tracing::trace!(
-                        "Stub-package in `{search_path} doesn't contain module: `{name}`"
+                        "Stub-package in `{search_path}` doesn't contain module: `{name}`"
                     );
                     // stub exists, but the module doesn't.
                     // TODO: Support partial packages.
@@ -606,7 +623,8 @@ fn resolve_name(db: &dyn Db, name: &ModuleName, mode: ModuleResolveMode) -> Opti
                 }
                 Err(PackageKind::Namespace) => {
                     tracing::trace!(
-                        "Stub-package in `{search_path} doesn't contain module: `{name}` but it is a namespace package, keep going."
+                        "Stub-package in `{search_path}` doesn't contain module: \
+                         `{name}` but it is a namespace package, keep going."
                     );
                     // stub exists, but the module doesn't. But this is a namespace package,
                     // keep searching the next search path for a stub package with the same name.
@@ -625,18 +643,19 @@ fn resolve_name(db: &dyn Db, name: &ModuleName, mode: ModuleResolveMode) -> Opti
             Err(kind) => match kind {
                 PackageKind::Root => {
                     tracing::trace!(
-                        "Search path '{search_path}' contains no package named `{name}`."
+                        "Search path `{search_path}` contains no package named `{name}`."
                     );
                 }
                 PackageKind::Regular => {
                     // For regular packages, don't search the next search path. All files of that
                     // package must be in the same location
-                    tracing::trace!("Package in `{search_path} doesn't contain module: `{name}`");
+                    tracing::trace!("Package in `{search_path}` doesn't contain module: `{name}`");
                     return None;
                 }
                 PackageKind::Namespace => {
                     tracing::trace!(
-                        "Package in `{search_path} doesn't contain module: `{name}` but it is a namespace package, keep going."
+                        "Package in `{search_path}` doesn't contain module: \
+                         `{name}` but it is a namespace package, keep going."
                     );
                 }
             },
@@ -657,7 +676,9 @@ enum ResolvedName {
 
     /// The module name resolved to a namespace package.
     ///
-    /// For example, `from opentelemetry import trace, metrics` where `opentelemetry` is a namespace package (and `trace` and `metrics` are sub packages).
+    /// For example, `from opentelemetry import trace, metrics` where
+    /// `opentelemetry` is a namespace package (and `trace` and `metrics` are
+    /// sub packages).
     NamespacePackage,
 }
 
@@ -668,6 +689,20 @@ struct ResolvedFileModule {
     file: File,
 }
 
+/// Attempts to resolve a module name in a particular search path.
+///
+/// `search_path` should be the directory to start looking for the module.
+///
+/// `name` should be a complete non-empty module name, e.g, `foo` or
+/// `foo.bar.baz`.
+///
+/// Upon success, this returns the kind of the parent package (root, regular
+/// package or namespace package) along with the resolved details of the
+/// module: its kind (single-file module or package), the search path in
+/// which it was found (guaranteed to be equal to the one given) and the
+/// corresponding `File`.
+///
+/// Upon error, the kind of the parent package is returned.
 fn resolve_name_in_search_path(
     context: &ResolverContext,
     name: &RelaxedModuleName,
@@ -709,19 +744,23 @@ fn resolve_name_in_search_path(
         ));
     }
 
-    // Last resort, check if a folder with the given name exists.
-    // If so, then this is a namespace package.
-    // We need to skip this check for typeshed because the `resolve_file_module` can also return `None`
-    // if the `__init__.py` exists but isn't available for the current Python version.
-    // Let's assume that the `xml` module is only available on Python 3.11+ and we're resolving for Python 3.10:
-    // * `resolve_file_module("xml/__init__.pyi")` returns `None` even though the file exists but the
-    //   module isn't available for the current Python version.
-    // * The check here would now return `true` because the `xml` directory exists, resulting
-    //   in a false positive for a namespace package.
+    // Last resort, check if a folder with the given name exists. If so,
+    // then this is a namespace package. We need to skip this check for
+    // typeshed because the `resolve_file_module` can also return `None` if the
+    // `__init__.py` exists but isn't available for the current Python version.
+    // Let's assume that the `xml` module is only available on Python 3.11+ and
+    // we're resolving for Python 3.10:
     //
-    // Since typeshed doesn't use any namespace packages today (May 2025), simply skip this
-    // check which also helps performance. If typeshed ever uses namespace packages, ensure that
-    // this check also takes the `VERSIONS` file into consideration.
+    // * `resolve_file_module("xml/__init__.pyi")` returns `None` even though
+    //   the file exists but the module isn't available for the current Python
+    //   version.
+    // * The check here would now return `true` because the `xml` directory
+    //   exists, resulting in a false positive for a namespace package.
+    //
+    // Since typeshed doesn't use any namespace packages today (May 2025),
+    // simply skip this check which also helps performance. If typeshed
+    // ever uses namespace packages, ensure that this check also takes the
+    // `VERSIONS` file into consideration.
     if !search_path.is_standard_library() && package_path.is_directory(context) {
         if let Some(path) = package_path.to_system_path() {
             let system = context.db.system();
@@ -773,6 +812,20 @@ fn resolve_file_module(module: &ModulePath, resolver_state: &ResolverContext) ->
     Some(file)
 }
 
+/// Attempt to resolve the parent package of a module.
+///
+/// `module_search_path` should be the directory to start looking for the
+/// parent package.
+///
+/// `components` should be the full module name of the parent package. This
+/// specifically should not include the basename of the module. So e.g.,
+/// for `foo.bar.baz`, `components` should be `[foo, bar]`. It follows that
+/// `components` may be empty (in which case, the parent package is the root).
+///
+/// Upon success, the path to the package and its "kind" (root, regular or
+/// namespace) is returned. Upon error, the kind of the package is still
+/// returned based on how many components were found and whether `__init__.py`
+/// is present.
 fn resolve_package<'a, 'db, I>(
     module_search_path: &SearchPath,
     components: I,
@@ -791,7 +844,7 @@ where
     // `true` if resolving a sub-package. For example, `true` when resolving `bar` of `foo.bar`.
     let mut in_sub_package = false;
 
-    // For `foo.bar.baz`, test that `foo` and `baz` both contain a `__init__.py`.
+    // For `foo.bar.baz`, test that `foo` and `bar` both contain a `__init__.py`.
     for folder in components {
         package_path.push(folder);
 
@@ -803,7 +856,8 @@ where
             // Pure modules hide namespace packages with the same name
             && resolve_file_module(&package_path, resolver_state).is_none()
         {
-            // A directory without an `__init__.py(i)` is a namespace package, continue with the next folder.
+            // A directory without an `__init__.py(i)` is a namespace package,
+            // continue with the next folder.
             in_namespace_package = true;
         } else if in_namespace_package {
             // Package not found but it is part of a namespace package.
@@ -849,9 +903,11 @@ enum PackageKind {
     /// For example, `bar` in `foo.bar` when the `foo` directory contains an `__init__.py`.
     Regular,
 
-    /// A sub-package in a namespace package. A namespace package is a package without an `__init__.py`.
+    /// A sub-package in a namespace package. A namespace package is a package
+    /// without an `__init__.py`.
     ///
-    /// For example, `bar` in `foo.bar` if the `foo` directory contains no `__init__.py`.
+    /// For example, `bar` in `foo.bar` if the `foo` directory contains no
+    /// `__init__.py`.
     Namespace,
 }
 
@@ -1488,8 +1544,8 @@ mod tests {
         db.memory_file_system().remove_file(&bar_path).unwrap();
         bar.sync(&mut db);
 
-        // Re-query the foo module. The foo module should still be cached because `bar.py` isn't relevant
-        // for resolving `foo`.
+        // Re-query the foo module. The foo module should still be cached
+        // because `bar.py` isn't relevant for resolving `foo`.
 
         let foo_module2 = resolve_module(&db, &foo_module_name);
         let foo_pieces2 = foo_module2.map(|foo_module2| {
@@ -2023,8 +2079,9 @@ not_a_directory
         db.write_file(src.join("main.py"), "print('Hy')")
             .context("Failed to write `main.py`")?;
 
-        // The symlink triggers the slow-path in the `OsSystem`'s `exists_path_case_sensitive`
-        // code because canonicalizing the path for `a/__init__.py` results in `a-package/__init__.py`
+        // The symlink triggers the slow-path in the `OsSystem`'s
+        // `exists_path_case_sensitive` code because canonicalizing the path
+        // for `a/__init__.py` results in `a-package/__init__.py`
         std::os::unix::fs::symlink(a_package_target.as_std_path(), a_src.as_std_path())
             .context("Failed to symlink `src/a` to `a-package`")?;
 
@@ -2043,7 +2100,8 @@ not_a_directory
         let a_module_name = ModuleName::new_static("A").unwrap();
         assert_eq!(resolve_module(&db, &a_module_name), None);
 
-        // Now lookup the same module using the lowercase `a` and it should resolve to the file in the system site-packages
+        // Now lookup the same module using the lowercase `a` and it should
+        // resolve to the file in the system site-packages
         let a_module_name = ModuleName::new_static("a").unwrap();
         let a_module = resolve_module(&db, &a_module_name).expect("a.py to resolve");
         assert!(

crates/ty_python_semantic/src/place.rs

@@ -641,7 +641,7 @@ fn place_cycle_initial<'db>(
     Place::bound(Type::Never).into()
 }
 
-#[salsa::tracked(cycle_fn=place_cycle_recover, cycle_initial=place_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(cycle_fn=place_cycle_recover, cycle_initial=place_cycle_initial, heap_size=get_size2::heap_size)]
 fn place_by_id<'db>(
     db: &'db dyn Db,
     scope: ScopeId<'db>,
@@ -1368,7 +1368,7 @@ mod implicit_globals {
     /// Conceptually this function could be a `Set` rather than a list,
     /// but the number of symbols declared in this scope is likely to be very small,
     /// so the cost of hashing the names is likely to be more expensive than it's worth.
-    #[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(returns(deref), heap_size=get_size2::heap_size)]
     fn module_type_symbols<'db>(db: &'db dyn Db) -> smallvec::SmallVec<[ast::name::Name; 8]> {
         let Some(module_type) = KnownClass::ModuleType
             .to_class_literal(db)

crates/ty_python_semantic/src/semantic_index.rs

@@ -52,7 +52,7 @@ pub(crate) use self::use_def::{
 /// Returns the semantic index for `file`.
 ///
 /// Prefer using [`symbol_table`] when working with symbols from a single scope.
-#[salsa::tracked(returns(ref), no_eq, heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(ref), no_eq, heap_size=get_size2::heap_size)]
 pub(crate) fn semantic_index(db: &dyn Db, file: File) -> SemanticIndex<'_> {
     let _span = tracing::trace_span!("semantic_index", ?file).entered();
 
@@ -66,7 +66,7 @@ pub(crate) fn semantic_index(db: &dyn Db, file: File) -> SemanticIndex<'_> {
 /// Using [`place_table`] over [`semantic_index`] has the advantage that
 /// Salsa can avoid invalidating dependent queries if this scope's place table
 /// is unchanged.
-#[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(deref), heap_size=get_size2::heap_size)]
 pub(crate) fn place_table<'db>(db: &'db dyn Db, scope: ScopeId<'db>) -> Arc<PlaceTable> {
     let file = scope.file(db);
     let _span = tracing::trace_span!("place_table", scope=?scope.as_id(), ?file).entered();
@@ -86,7 +86,7 @@ pub(crate) fn place_table<'db>(db: &'db dyn Db, scope: ScopeId<'db>) -> Arc<Plac
 ///
 ///   - We cannot resolve relative imports (which aren't allowed in `import` statements) without
 ///     knowing the name of the current module, and whether it's a package.
-#[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(deref), heap_size=get_size2::heap_size)]
 pub(crate) fn imported_modules<'db>(db: &'db dyn Db, file: File) -> Arc<FxHashSet<ModuleName>> {
     semantic_index(db, file).imported_modules.clone()
 }
@@ -96,7 +96,7 @@ pub(crate) fn imported_modules<'db>(db: &'db dyn Db, file: File) -> Arc<FxHashSe
 /// Using [`use_def_map`] over [`semantic_index`] has the advantage that
 /// Salsa can avoid invalidating dependent queries if this scope's use-def map
 /// is unchanged.
-#[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(deref), heap_size=get_size2::heap_size)]
 pub(crate) fn use_def_map<'db>(db: &'db dyn Db, scope: ScopeId<'db>) -> ArcUseDefMap<'db> {
     let file = scope.file(db);
     let _span = tracing::trace_span!("use_def_map", scope=?scope.as_id(), ?file).entered();
@@ -184,7 +184,7 @@ pub(crate) fn attribute_scopes<'db, 's>(
 }
 
 /// Returns the module global scope of `file`.
-#[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(heap_size=get_size2::heap_size)]
 pub(crate) fn global_scope(db: &dyn Db, file: File) -> ScopeId<'_> {
     let _span = tracing::trace_span!("global_scope", ?file).entered();
 

crates/ty_python_semantic/src/semantic_index/builder.rs

@@ -49,7 +49,7 @@ use crate::semantic_index::use_def::{
 };
 use crate::semantic_index::{ArcUseDefMap, ExpressionsScopeMap, SemanticIndex};
 use crate::semantic_model::HasTrackedScope;
-use crate::unpack::{Unpack, UnpackKind, UnpackPosition, UnpackValue};
+use crate::unpack::{EvaluationMode, Unpack, UnpackKind, UnpackPosition, UnpackValue};
 use crate::{Db, Program};
 
 mod except_handlers;
@@ -2804,8 +2804,18 @@ impl<'ast> Unpackable<'ast> {
     const fn kind(&self) -> UnpackKind {
         match self {
             Unpackable::Assign(_) => UnpackKind::Assign,
-            Unpackable::For(_) | Unpackable::Comprehension { .. } => UnpackKind::Iterable,
-            Unpackable::WithItem { .. } => UnpackKind::ContextManager,
+            Unpackable::For(ast::StmtFor { is_async, .. }) => UnpackKind::Iterable {
+                mode: EvaluationMode::from_is_async(*is_async),
+            },
+            Unpackable::Comprehension {
+                node: ast::Comprehension { is_async, .. },
+                ..
+            } => UnpackKind::Iterable {
+                mode: EvaluationMode::from_is_async(*is_async),
+            },
+            Unpackable::WithItem { is_async, .. } => UnpackKind::ContextManager {
+                mode: EvaluationMode::from_is_async(*is_async),
+            },
         }
     }
 

crates/ty_python_semantic/src/semantic_index/re_exports.rs

@@ -43,7 +43,7 @@ fn exports_cycle_initial(_db: &dyn Db, _file: File) -> Box<[Name]> {
     Box::default()
 }
 
-#[salsa::tracked(returns(deref), cycle_fn=exports_cycle_recover, cycle_initial=exports_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(deref), cycle_fn=exports_cycle_recover, cycle_initial=exports_cycle_initial, heap_size=get_size2::heap_size)]
 pub(super) fn exported_names(db: &dyn Db, file: File) -> Box<[Name]> {
     let module = parsed_module(db, file).load(db);
     let mut finder = ExportFinder::new(db, file);

crates/ty_python_semantic/src/semantic_model.rs

@@ -222,7 +222,6 @@ impl<'db> Completion<'db> {
                 // "struct" here as a more general "object." ---AG
                 Type::NominalInstance(_)
                 | Type::PropertyInstance(_)
-                | Type::Tuple(_)
                 | Type::BoundSuper(_) => CompletionKind::Struct,
                 Type::IntLiteral(_)
                 | Type::BooleanLiteral(_)

crates/ty_python_semantic/src/suppression.rs

@@ -86,7 +86,7 @@ declare_lint! {
     }
 }
 
-#[salsa::tracked(returns(ref), heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(ref), heap_size=get_size2::heap_size)]
 pub(crate) fn suppressions(db: &dyn Db, file: File) -> Suppressions {
     let parsed = parsed_module(db, file).load(db);
     let source = source_text(db, file);

crates/ty_python_semantic/src/types.rs

@@ -59,6 +59,7 @@ use crate::types::mro::{Mro, MroError, MroIterator};
 pub(crate) use crate::types::narrow::infer_narrowing_constraint;
 use crate::types::signatures::{Parameter, ParameterForm, Parameters, walk_signature};
 use crate::types::tuple::{TupleSpec, TupleType};
+use crate::unpack::EvaluationMode;
 pub use crate::util::diagnostics::add_inferred_python_version_hint_to_diagnostic;
 use crate::{Db, FxOrderSet, Module, Program};
 pub(crate) use class::{ClassLiteral, ClassType, GenericAlias, KnownClass};
@@ -591,11 +592,6 @@ pub enum Type<'db> {
     LiteralString,
     /// A bytes literal
     BytesLiteral(BytesLiteralType<'db>),
-    /// An instance of the builtin `tuple` class.
-    /// TODO: Consider removing this in favor of `NominalInstance`. This is currently stored as a
-    /// separate variant partly for historical reasons, and partly to allow us to easily
-    /// distinguish tuples since they occur so often.
-    Tuple(TupleType<'db>),
     /// An instance of a typevar in a generic class or function. When the generic class or function
     /// is specialized, we will replace this typevar with its specialization.
     TypeVar(TypeVarInstance<'db>),
@@ -680,6 +676,30 @@ impl<'db> Type<'db> {
         self.materialize(db, TypeVarVariance::Contravariant)
     }
 
+    /// If this type is an instance type where the class has a tuple spec, returns the tuple spec.
+    ///
+    /// I.e., for the type `tuple[int, str]`, this will return the tuple spec `[int, str]`.
+    /// For a subclass of `tuple[int, str]`, it will return the same tuple spec.
+    fn tuple_instance_spec(&self, db: &'db dyn Db) -> Option<Cow<'db, TupleSpec<'db>>> {
+        self.into_nominal_instance()
+            .and_then(|instance| instance.class.tuple_spec(db))
+    }
+
+    /// If this type is an *exact* tuple type (*not* a subclass of `tuple`), returns the
+    /// tuple spec.
+    ///
+    /// You usually don't want to use this method, as you usually want to consider a subclass
+    /// of a tuple type in the same way as the `tuple` type itself. Only use this method if you
+    /// are certain that a *literal tuple* is required, and that a subclass of tuple will not
+    /// do.
+    ///
+    /// I.e., for the type `tuple[int, str]`, this will return the tuple spec `[int, str]`.
+    /// But for a subclass of `tuple[int, str]`, it will return `None`.
+    fn exact_tuple_instance_spec(&self, db: &'db dyn Db) -> Option<Cow<'db, TupleSpec<'db>>> {
+        self.into_nominal_instance()
+            .and_then(|instance| instance.class.own_tuple_spec(db))
+    }
+
     /// Returns the materialization of this type depending on the given `variance`.
     ///
     /// More concretely, `T'`, the materialization of `T`, is the type `T` with all occurrences of
@@ -773,7 +793,6 @@ impl<'db> Type<'db> {
                         .map(|ty| ty.materialize(db, variance.flip())),
                 )
                 .build(),
-            Type::Tuple(tuple_type) => Type::tuple(tuple_type.materialize(db, variance)),
             Type::TypeVar(type_var) => Type::TypeVar(type_var.materialize(db, variance)),
             Type::TypeIs(type_is) => {
                 type_is.with_type(db, type_is.return_type(db).materialize(db, variance))
@@ -1022,9 +1041,6 @@ impl<'db> Type<'db> {
             Type::Intersection(intersection) => visitor.visit(self, |v| {
                 Type::Intersection(intersection.normalized_impl(db, v))
             }),
-            Type::Tuple(tuple) => {
-                visitor.visit(self, |v| Type::tuple(tuple.normalized_impl(db, v)))
-            }
             Type::Callable(callable) => {
                 visitor.visit(self, |v| Type::Callable(callable.normalized_impl(db, v)))
             }
@@ -1128,7 +1144,6 @@ impl<'db> Type<'db> {
             | Type::Union(_)
             | Type::Intersection(_)
             | Type::Callable(_)
-            | Type::Tuple(_)
             | Type::TypeVar(_)
             | Type::BoundSuper(_)
             | Type::TypeIs(_) => false,
@@ -1193,7 +1208,6 @@ impl<'db> Type<'db> {
             | Type::StringLiteral(_)
             | Type::LiteralString
             | Type::BytesLiteral(_)
-            | Type::Tuple(_)
             | Type::TypeIs(_) => None,
 
             // TODO
@@ -1527,24 +1541,6 @@ impl<'db> Type<'db> {
 
             (Type::Callable(_), _) => false,
 
-            (Type::Tuple(self_tuple), Type::Tuple(target_tuple)) => {
-                self_tuple.has_relation_to(db, target_tuple, relation)
-            }
-
-            (Type::Tuple(self_tuple), Type::NominalInstance(target_instance)) => {
-                self_tuple.to_class_type(db).is_some_and(|self_class| {
-                    self_class.has_relation_to(db, target_instance.class, relation)
-                })
-            }
-            (Type::NominalInstance(self_instance), Type::Tuple(target_tuple)) => {
-                target_tuple.to_class_type(db).is_some_and(|target_class| {
-                    self_instance
-                        .class
-                        .has_relation_to(db, target_class, relation)
-                })
-            }
-            (Type::Tuple(_), _) => false,
-
             (Type::BoundSuper(_), Type::BoundSuper(_)) => self.is_equivalent_to(db, target),
             (Type::BoundSuper(_), _) => KnownClass::Super
                 .to_instance(db)
@@ -1674,8 +1670,6 @@ impl<'db> Type<'db> {
                 first.is_equivalent_to(db, second)
             }
 
-            (Type::Tuple(first), Type::Tuple(second)) => first.is_equivalent_to(db, second),
-
             (Type::Union(first), Type::Union(second)) => first.is_equivalent_to(db, second),
 
             (Type::Intersection(first), Type::Intersection(second)) => {
@@ -1851,45 +1845,6 @@ impl<'db> Type<'db> {
                 | Type::KnownInstance(..)),
             ) => left != right,
 
-            // One tuple type can be a subtype of another tuple type,
-            // but we know for sure that any given tuple type is disjoint from all single-valued types
-            (
-                Type::Tuple(..),
-                Type::ClassLiteral(..)
-                | Type::GenericAlias(..)
-                | Type::ModuleLiteral(..)
-                | Type::BooleanLiteral(..)
-                | Type::BytesLiteral(..)
-                | Type::FunctionLiteral(..)
-                | Type::BoundMethod(..)
-                | Type::MethodWrapper(..)
-                | Type::WrapperDescriptor(..)
-                | Type::DataclassDecorator(..)
-                | Type::DataclassTransformer(..)
-                | Type::IntLiteral(..)
-                | Type::EnumLiteral(..)
-                | Type::StringLiteral(..)
-                | Type::LiteralString,
-            )
-            | (
-                Type::ClassLiteral(..)
-                | Type::GenericAlias(..)
-                | Type::ModuleLiteral(..)
-                | Type::BooleanLiteral(..)
-                | Type::BytesLiteral(..)
-                | Type::FunctionLiteral(..)
-                | Type::BoundMethod(..)
-                | Type::MethodWrapper(..)
-                | Type::WrapperDescriptor(..)
-                | Type::DataclassDecorator(..)
-                | Type::DataclassTransformer(..)
-                | Type::IntLiteral(..)
-                | Type::EnumLiteral(..)
-                | Type::StringLiteral(..)
-                | Type::LiteralString,
-                Type::Tuple(..),
-            ) => true,
-
             (
                 Type::SubclassOf(_),
                 Type::BooleanLiteral(..)
@@ -2060,16 +2015,6 @@ impl<'db> Type<'db> {
                 !known_instance.is_instance_of(db, instance.class)
             }
 
-            (Type::SpecialForm(special_form), Type::Tuple(tuple))
-            | (Type::Tuple(tuple), Type::SpecialForm(special_form)) => tuple
-                .to_class_type(db)
-                .is_some_and(|tuple_class| !special_form.is_instance_of(db, tuple_class)),
-
-            (Type::KnownInstance(known_instance), Type::Tuple(tuple))
-            | (Type::Tuple(tuple), Type::KnownInstance(known_instance)) => tuple
-                .to_class_type(db)
-                .is_some_and(|tuple_class| !known_instance.is_instance_of(db, tuple_class)),
-
             (Type::BooleanLiteral(..) | Type::TypeIs(_), Type::NominalInstance(instance))
             | (Type::NominalInstance(instance), Type::BooleanLiteral(..) | Type::TypeIs(_)) => {
                 // A `Type::BooleanLiteral()` must be an instance of exactly `bool`
@@ -2218,17 +2163,6 @@ impl<'db> Type<'db> {
                 left.is_disjoint_from_impl(db, right)
             }
 
-            (Type::Tuple(tuple), Type::Tuple(other_tuple)) => {
-                tuple.is_disjoint_from_impl(db, other_tuple, visitor)
-            }
-
-            (Type::Tuple(tuple), Type::NominalInstance(instance))
-            | (Type::NominalInstance(instance), Type::Tuple(tuple)) => {
-                tuple.to_class_type(db).is_some_and(|tuple_class| {
-                    !instance.class.could_coexist_in_mro_with(db, tuple_class)
-                })
-            }
-
             (Type::PropertyInstance(_), other) | (other, Type::PropertyInstance(_)) => {
                 KnownClass::Property
                     .to_instance(db)
@@ -2339,14 +2273,6 @@ impl<'db> Type<'db> {
             Type::DataclassDecorator(_) | Type::DataclassTransformer(_) => false,
             Type::NominalInstance(instance) => instance.is_singleton(db),
             Type::PropertyInstance(_) => false,
-            Type::Tuple(..) => {
-                // The empty tuple is a singleton on CPython and PyPy, but not on other Python
-                // implementations such as GraalPy. Its *use* as a singleton is discouraged and
-                // should not be relied on for type narrowing, so we do not treat it as one.
-                // See:
-                // https://docs.python.org/3/reference/expressions.html#parenthesized-forms
-                false
-            }
             Type::Union(..) => {
                 // A single-element union, where the sole element was a singleton, would itself
                 // be a singleton type. However, unions with length < 2 should never appear in
@@ -2433,7 +2359,6 @@ impl<'db> Type<'db> {
                 false
             }
 
-            Type::Tuple(tuple) => tuple.is_single_valued(db),
             Type::NominalInstance(instance) => instance.is_single_valued(db),
 
             Type::BoundSuper(_) => {
@@ -2568,7 +2493,6 @@ impl<'db> Type<'db> {
             | Type::LiteralString
             | Type::BytesLiteral(_)
             | Type::EnumLiteral(_)
-            | Type::Tuple(_)
             | Type::TypeVar(_)
             | Type::NominalInstance(_)
             | Type::ProtocolInstance(_)
@@ -2577,7 +2501,7 @@ impl<'db> Type<'db> {
         }
     }
 
-    #[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(heap_size=get_size2::heap_size)]
     #[allow(unused_variables)]
     // If we choose name `_unit`, the macro will generate code that uses `_unit`, causing clippy to fail.
     fn lookup_dunder_new(self, db: &'db dyn Db, unit: ()) -> Option<PlaceAndQualifiers<'db>> {
@@ -2598,7 +2522,7 @@ impl<'db> Type<'db> {
         self.class_member_with_policy(db, name, MemberLookupPolicy::default())
     }
 
-    #[salsa::tracked(cycle_fn=class_lookup_cycle_recover, cycle_initial=class_lookup_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(cycle_fn=class_lookup_cycle_recover, cycle_initial=class_lookup_cycle_initial, heap_size=get_size2::heap_size)]
     fn class_member_with_policy(
         self,
         db: &'db dyn Db,
@@ -2700,10 +2624,6 @@ impl<'db> Type<'db> {
             Type::EnumLiteral(enum_literal) => enum_literal
                 .enum_class_instance(db)
                 .instance_member(db, name),
-            Type::Tuple(tuple) => tuple
-                .to_class_type(db)
-                .map(|class| class.instance_member(db, name))
-                .unwrap_or(Place::Unbound.into()),
 
             Type::AlwaysTruthy | Type::AlwaysFalsy => Type::object(db).instance_member(db, name),
             Type::ModuleLiteral(_) => KnownClass::ModuleType
@@ -2759,7 +2679,7 @@ impl<'db> Type<'db> {
     /// that `self` represents: (1) a data descriptor or (2) a non-data descriptor / normal attribute.
     ///
     /// If `__get__` is not defined on the meta-type, this method returns `None`.
-    #[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(heap_size=get_size2::heap_size)]
     pub(crate) fn try_call_dunder_get(
         self,
         db: &'db dyn Db,
@@ -3052,7 +2972,7 @@ impl<'db> Type<'db> {
 
     /// Similar to [`Type::member`], but allows the caller to specify what policy should be used
     /// when looking up attributes. See [`MemberLookupPolicy`] for more information.
-    #[salsa::tracked(cycle_fn=member_lookup_cycle_recover, cycle_initial=member_lookup_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(cycle_fn=member_lookup_cycle_recover, cycle_initial=member_lookup_cycle_initial, heap_size=get_size2::heap_size)]
     fn member_lookup_with_policy(
         self,
         db: &'db dyn Db,
@@ -3211,7 +3131,6 @@ impl<'db> Type<'db> {
             | Type::BytesLiteral(..)
             | Type::EnumLiteral(..)
             | Type::LiteralString
-            | Type::Tuple(..)
             | Type::TypeVar(..)
             | Type::SpecialForm(..)
             | Type::KnownInstance(..)
@@ -3568,7 +3487,6 @@ impl<'db> Type<'db> {
             Type::BooleanLiteral(bool) => Truthiness::from(*bool),
             Type::StringLiteral(str) => Truthiness::from(!str.value(db).is_empty()),
             Type::BytesLiteral(bytes) => Truthiness::from(!bytes.value(db).is_empty()),
-            Type::Tuple(tuple) => tuple.truthiness(db),
         };
 
         Ok(truthiness)
@@ -3595,13 +3513,6 @@ impl<'db> Type<'db> {
         let usize_len = match self {
             Type::BytesLiteral(bytes) => Some(bytes.python_len(db)),
             Type::StringLiteral(string) => Some(string.python_len(db)),
-
-            // N.B. This is strictly-speaking redundant, since the `__len__` method on tuples
-            // is special-cased in `ClassType::own_class_member`. However, it's probably more
-            // efficient to short-circuit here and check against the tuple spec directly,
-            // rather than going through the `__len__` method.
-            Type::Tuple(tuple) => tuple.tuple(db).len().into_fixed_length(),
-
             _ => None,
         };
 
@@ -4540,7 +4451,6 @@ impl<'db> Type<'db> {
             | Type::BytesLiteral(_)
             | Type::BooleanLiteral(_)
             | Type::LiteralString
-            | Type::Tuple(_)
             | Type::BoundSuper(_)
             | Type::ModuleLiteral(_)
             | Type::TypeIs(_) => CallableBinding::not_callable(self).into(),
@@ -4637,8 +4547,71 @@ impl<'db> Type<'db> {
     /// y(*x)
     /// ```
     fn try_iterate(self, db: &'db dyn Db) -> Result<Cow<'db, TupleSpec<'db>>, IterationError<'db>> {
+        self.try_iterate_with_mode(db, EvaluationMode::Sync)
+    }
+
+    fn try_iterate_with_mode(
+        self,
+        db: &'db dyn Db,
+        mode: EvaluationMode,
+    ) -> Result<Cow<'db, TupleSpec<'db>>, IterationError<'db>> {
+        if mode.is_async() {
+            let try_call_dunder_anext_on_iterator = |iterator: Type<'db>| {
+                iterator
+                    .try_call_dunder(db, "__anext__", CallArguments::none())
+                    .map(|dunder_anext_outcome| {
+                        dunder_anext_outcome.return_type(db).resolve_await(db)
+                    })
+            };
+
+            return match self.try_call_dunder(db, "__aiter__", CallArguments::none()) {
+                Ok(dunder_aiter_bindings) => {
+                    let iterator = dunder_aiter_bindings.return_type(db);
+                    match try_call_dunder_anext_on_iterator(iterator) {
+                        Ok(result) => Ok(Cow::Owned(TupleSpec::homogeneous(result))),
+                        Err(dunder_anext_error) => {
+                            Err(IterationError::IterReturnsInvalidIterator {
+                                iterator,
+                                dunder_error: dunder_anext_error,
+                                mode,
+                            })
+                        }
+                    }
+                }
+                Err(CallDunderError::PossiblyUnbound(dunder_aiter_bindings)) => {
+                    let iterator = dunder_aiter_bindings.return_type(db);
+                    match try_call_dunder_anext_on_iterator(iterator) {
+                        Ok(_) => Err(IterationError::IterCallError {
+                            kind: CallErrorKind::PossiblyNotCallable,
+                            bindings: dunder_aiter_bindings,
+                            mode,
+                        }),
+                        Err(dunder_anext_error) => {
+                            Err(IterationError::IterReturnsInvalidIterator {
+                                iterator,
+                                dunder_error: dunder_anext_error,
+                                mode,
+                            })
+                        }
+                    }
+                }
+                Err(CallDunderError::CallError(kind, bindings)) => {
+                    Err(IterationError::IterCallError {
+                        kind,
+                        bindings,
+                        mode,
+                    })
+                }
+                Err(CallDunderError::MethodNotAvailable) => Err(IterationError::UnboundAiterError),
+            };
+        }
+
         match self {
-            Type::Tuple(tuple_type) => return Ok(Cow::Borrowed(tuple_type.tuple(db))),
+            Type::NominalInstance(NominalInstanceType { class, .. }) => {
+                if let Some(spec) = class.tuple_spec(db) {
+                    return Ok(spec);
+                }
+            }
             Type::GenericAlias(alias) if alias.origin(db).is_tuple(db) => {
                 return Ok(Cow::Owned(TupleSpec::homogeneous(todo_type!(
                     "*tuple[] annotations"
@@ -4693,7 +4666,8 @@ impl<'db> Type<'db> {
                     .map_err(
                         |dunder_next_error| IterationError::IterReturnsInvalidIterator {
                             iterator,
-                            dunder_next_error,
+                            dunder_error: dunder_next_error,
+                            mode,
                         },
                     )
             }
@@ -4728,15 +4702,18 @@ impl<'db> Type<'db> {
 
                     Err(dunder_next_error) => Err(IterationError::IterReturnsInvalidIterator {
                         iterator,
-                        dunder_next_error,
+                        dunder_error: dunder_next_error,
+                        mode,
                     }),
                 }
             }
 
             // `__iter__` is definitely bound but it can't be called with the expected arguments
-            Err(CallDunderError::CallError(kind, bindings)) => {
-                Err(IterationError::IterCallError(kind, bindings))
-            }
+            Err(CallDunderError::CallError(kind, bindings)) => Err(IterationError::IterCallError {
+                kind,
+                bindings,
+                mode,
+            }),
 
             // There's no `__iter__` method. Try `__getitem__` instead...
             Err(CallDunderError::MethodNotAvailable) => try_call_dunder_getitem()
@@ -4790,6 +4767,64 @@ impl<'db> Type<'db> {
         }
     }
 
+    /// Similar to [`Self::try_enter`], but for async context managers.
+    fn aenter(self, db: &'db dyn Db) -> Type<'db> {
+        // TODO: Add proper error handling and rename this method to `try_aenter`.
+        self.try_call_dunder(db, "__aenter__", CallArguments::none())
+            .map_or(Type::unknown(), |result| {
+                result.return_type(db).resolve_await(db)
+            })
+    }
+
+    /// Resolve the type of an `await …` expression where `self` is the type of the awaitable.
+    fn resolve_await(self, db: &'db dyn Db) -> Type<'db> {
+        // TODO: Add proper error handling and rename this method to `try_await`.
+        self.try_call_dunder(db, "__await__", CallArguments::none())
+            .map_or(Type::unknown(), |result| {
+                result
+                    .return_type(db)
+                    .generator_return_type(db)
+                    .unwrap_or_else(Type::unknown)
+            })
+    }
+
+    /// Get the return type of a `yield from …` expression where `self` is the type of the generator.
+    ///
+    /// This corresponds to the `ReturnT` parameter of the generic `typing.Generator[YieldT, SendT, ReturnT]`
+    /// protocol.
+    fn generator_return_type(self, db: &'db dyn Db) -> Option<Type<'db>> {
+        // TODO: Ideally, we would first try to upcast `self` to an instance of `Generator` and *then*
+        // match on the protocol instance to get the `ReturnType` type parameter. For now, implement
+        // an ad-hoc solution that works for protocols and instances of classes that explicitly inherit
+        // from the `Generator` protocol, such as `types.GeneratorType`.
+
+        let from_class_base = |base: ClassBase<'db>| {
+            let class = base.into_class()?;
+            if class.is_known(db, KnownClass::Generator) {
+                if let Some(specialization) = class.class_literal_specialized(db, None).1 {
+                    if let [_, _, return_ty] = specialization.types(db) {
+                        return Some(*return_ty);
+                    }
+                }
+            }
+            None
+        };
+
+        match self {
+            Type::NominalInstance(instance) => {
+                instance.class.iter_mro(db).find_map(from_class_base)
+            }
+            Type::ProtocolInstance(instance) => {
+                if let Protocol::FromClass(class) = instance.inner {
+                    class.iter_mro(db).find_map(from_class_base)
+                } else {
+                    None
+                }
+            }
+            _ => None,
+        }
+    }
+
     /// Given a class literal or non-dynamic SubclassOf type, try calling it (creating an instance)
     /// and return the resulting instance type.
     ///
@@ -5031,7 +5066,6 @@ impl<'db> Type<'db> {
             | Type::ModuleLiteral(_)
             | Type::IntLiteral(_)
             | Type::StringLiteral(_)
-            | Type::Tuple(_)
             | Type::LiteralString
             | Type::BoundSuper(_)
             | Type::AlwaysTruthy
@@ -5091,7 +5125,6 @@ impl<'db> Type<'db> {
             | Type::LiteralString
             | Type::ModuleLiteral(_)
             | Type::StringLiteral(_)
-            | Type::Tuple(_)
             | Type::TypeVar(_)
             | Type::Callable(_)
             | Type::BoundMethod(_)
@@ -5310,40 +5343,6 @@ impl<'db> Type<'db> {
         KnownClass::NoneType.to_instance(db)
     }
 
-    /// Return the type of `tuple(sys.version_info)`.
-    ///
-    /// This is not exactly the type that `sys.version_info` has at runtime,
-    /// but it's a useful fallback for us in order to infer `Literal` types from `sys.version_info` comparisons.
-    fn version_info_tuple(db: &'db dyn Db) -> Self {
-        let python_version = Program::get(db).python_version(db);
-        let int_instance_ty = KnownClass::Int.to_instance(db);
-
-        // TODO: just grab this type from typeshed (it's a `sys._ReleaseLevel` type alias there)
-        let release_level_ty = {
-            let elements: Box<[Type<'db>]> = ["alpha", "beta", "candidate", "final"]
-                .iter()
-                .map(|level| Type::string_literal(db, level))
-                .collect();
-
-            // For most unions, it's better to go via `UnionType::from_elements` or use `UnionBuilder`;
-            // those techniques ensure that union elements are deduplicated and unions are eagerly simplified
-            // into other types where necessary. Here, however, we know that there are no duplicates
-            // in this union, so it's probably more efficient to use `UnionType::new()` directly.
-            Type::Union(UnionType::new(db, elements))
-        };
-
-        TupleType::from_elements(
-            db,
-            [
-                Type::IntLiteral(python_version.major.into()),
-                Type::IntLiteral(python_version.minor.into()),
-                int_instance_ty,
-                release_level_ty,
-                int_instance_ty,
-            ],
-        )
-    }
-
     /// Given a type that is assumed to represent an instance of a class,
     /// return a type that represents that class itself.
     #[must_use]
@@ -5369,10 +5368,6 @@ impl<'db> Type<'db> {
             }
             Type::Callable(_) | Type::DataclassTransformer(_) => KnownClass::Type.to_instance(db),
             Type::ModuleLiteral(_) => KnownClass::ModuleType.to_class_literal(db),
-            Type::Tuple(tuple) => tuple
-                .to_class_type(db)
-                .map(Type::from)
-                .unwrap_or_else(Type::unknown),
 
             Type::TypeVar(typevar) => match typevar.bound_or_constraints(db) {
                 None => KnownClass::Type.to_instance(db),
@@ -5428,7 +5423,7 @@ impl<'db> Type<'db> {
     /// Note that this does not specialize generic classes, functions, or type aliases! That is a
     /// different operation that is performed explicitly (via a subscript operation), or implicitly
     /// via a call to the generic object.
-    #[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(heap_size=get_size2::heap_size)]
     pub fn apply_specialization(
         self,
         db: &'db dyn Db,
@@ -5526,7 +5521,6 @@ impl<'db> Type<'db> {
                 }
                 builder.build()
             }
-            Type::Tuple(tuple) => Type::tuple(tuple.apply_type_mapping(db, type_mapping)),
 
             Type::TypeIs(type_is) => type_is.with_type(db, type_is.return_type(db).apply_type_mapping(db, type_mapping)),
 
@@ -5619,10 +5613,6 @@ impl<'db> Type<'db> {
                 }
             }
 
-            Type::Tuple(tuple) => {
-                tuple.find_legacy_typevars(db, typevars);
-            }
-
             Type::GenericAlias(alias) => {
                 alias.find_legacy_typevars(db, typevars);
             }
@@ -5766,8 +5756,7 @@ impl<'db> Type<'db> {
             | Self::DataclassDecorator(_)
             | Self::DataclassTransformer(_)
             | Self::PropertyInstance(_)
-            | Self::BoundSuper(_)
-            | Self::Tuple(_) => self.to_meta_type(db).definition(db),
+            | Self::BoundSuper(_) => self.to_meta_type(db).definition(db),
 
             Self::TypeVar(var) => Some(TypeDefinition::TypeVar(var.definition(db)?)),
 
@@ -6748,18 +6737,24 @@ impl<'db> ContextManagerError<'db> {
 /// Error returned if a type is not (or may not be) iterable.
 #[derive(Debug)]
 enum IterationError<'db> {
-    /// The object being iterated over has a bound `__iter__` method,
+    /// The object being iterated over has a bound `__(a)iter__` method,
     /// but calling it with the expected arguments results in an error.
-    IterCallError(CallErrorKind, Box<Bindings<'db>>),
+    IterCallError {
+        kind: CallErrorKind,
+        bindings: Box<Bindings<'db>>,
+        mode: EvaluationMode,
+    },
 
-    /// The object being iterated over has a bound `__iter__` method that can be called
+    /// The object being iterated over has a bound `__(a)iter__` method that can be called
     /// with the expected types, but it returns an object that is not a valid iterator.
     IterReturnsInvalidIterator {
-        /// The type of the object returned by the `__iter__` method.
+        /// The type of the object returned by the `__(a)iter__` method.
         iterator: Type<'db>,
-        /// The error we encountered when we tried to call `__next__` on the type
-        /// returned by `__iter__`
-        dunder_next_error: CallDunderError<'db>,
+        /// The error we encountered when we tried to call `__(a)next__` on the type
+        /// returned by `__(a)iter__`
+        dunder_error: CallDunderError<'db>,
+        /// Whether this is a synchronous or an asynchronous iterator.
+        mode: EvaluationMode,
     },
 
     /// The object being iterated over has a bound `__iter__` method that returns a
@@ -6780,6 +6775,9 @@ enum IterationError<'db> {
     UnboundIterAndGetitemError {
         dunder_getitem_error: CallDunderError<'db>,
     },
+
+    /// The asynchronous iterable has no `__aiter__` method.
+    UnboundAiterError,
 }
 
 impl<'db> IterationError<'db> {
@@ -6789,16 +6787,43 @@ impl<'db> IterationError<'db> {
 
     /// Returns the element type if it is known, or `None` if the type is never iterable.
     fn element_type(&self, db: &'db dyn Db) -> Option<Type<'db>> {
+        let return_type = |result: Result<Bindings<'db>, CallDunderError<'db>>| {
+            result
+                .map(|outcome| Some(outcome.return_type(db)))
+                .unwrap_or_else(|call_error| call_error.return_type(db))
+        };
+
         match self {
             Self::IterReturnsInvalidIterator {
-                dunder_next_error, ..
-            } => dunder_next_error.return_type(db),
+                dunder_error, mode, ..
+            } => dunder_error.return_type(db).map(|ty| {
+                if mode.is_async() {
+                    ty.resolve_await(db)
+                } else {
+                    ty
+                }
+            }),
 
-            Self::IterCallError(_, dunder_iter_bindings) => dunder_iter_bindings
-                .return_type(db)
-                .try_call_dunder(db, "__next__", CallArguments::none())
-                .map(|dunder_next_outcome| Some(dunder_next_outcome.return_type(db)))
-                .unwrap_or_else(|dunder_next_call_error| dunder_next_call_error.return_type(db)),
+            Self::IterCallError {
+                kind: _,
+                bindings: dunder_iter_bindings,
+                mode,
+            } => {
+                if mode.is_async() {
+                    return_type(dunder_iter_bindings.return_type(db).try_call_dunder(
+                        db,
+                        "__anext__",
+                        CallArguments::none(),
+                    ))
+                    .map(|ty| ty.resolve_await(db))
+                } else {
+                    return_type(dunder_iter_bindings.return_type(db).try_call_dunder(
+                        db,
+                        "__next__",
+                        CallArguments::none(),
+                    ))
+                }
+            }
 
             Self::PossiblyUnboundIterAndGetitemError {
                 dunder_next_return,
@@ -6824,6 +6849,19 @@ impl<'db> IterationError<'db> {
             Self::UnboundIterAndGetitemError {
                 dunder_getitem_error,
             } => dunder_getitem_error.return_type(db),
+
+            Self::UnboundAiterError => None,
+        }
+    }
+
+    /// Does this error concern a synchronous or asynchronous iterable?
+    fn mode(&self) -> EvaluationMode {
+        match self {
+            Self::IterCallError { mode, .. } => *mode,
+            Self::IterReturnsInvalidIterator { mode, .. } => *mode,
+            Self::PossiblyUnboundIterAndGetitemError { .. }
+            | Self::UnboundIterAndGetitemError { .. } => EvaluationMode::Sync,
+            Self::UnboundAiterError => EvaluationMode::Async,
         }
     }
 
@@ -6840,6 +6878,7 @@ impl<'db> IterationError<'db> {
             db: &'a dyn Db,
             builder: LintDiagnosticGuardBuilder<'a, 'a>,
             iterable_type: Type<'a>,
+            mode: EvaluationMode,
         }
 
         impl<'a> Reporter<'a> {
@@ -6849,8 +6888,9 @@ impl<'db> IterationError<'db> {
             #[expect(clippy::wrong_self_convention)]
             fn is_not(self, because: impl std::fmt::Display) -> LintDiagnosticGuard<'a, 'a> {
                 let mut diag = self.builder.into_diagnostic(format_args!(
-                    "Object of type `{iterable_type}` is not iterable",
+                    "Object of type `{iterable_type}` is not {maybe_async}iterable",
                     iterable_type = self.iterable_type.display(self.db),
+                    maybe_async = if self.mode.is_async() { "async-" } else { "" }
                 ));
                 diag.info(because);
                 diag
@@ -6861,8 +6901,9 @@ impl<'db> IterationError<'db> {
             /// `because` should explain why `iterable_type` is likely not iterable.
             fn may_not(self, because: impl std::fmt::Display) -> LintDiagnosticGuard<'a, 'a> {
                 let mut diag = self.builder.into_diagnostic(format_args!(
-                    "Object of type `{iterable_type}` may not be iterable",
+                    "Object of type `{iterable_type}` may not be {maybe_async}iterable",
                     iterable_type = self.iterable_type.display(self.db),
+                    maybe_async = if self.mode.is_async() { "async-" } else { "" }
                 ));
                 diag.info(because);
                 diag
@@ -6873,106 +6914,132 @@ impl<'db> IterationError<'db> {
             return;
         };
         let db = context.db();
+        let mode = self.mode();
         let reporter = Reporter {
             db,
             builder,
             iterable_type,
+            mode,
         };
 
         // TODO: for all of these error variants, the "explanation" for the diagnostic
         // (everything after the "because") should really be presented as a "help:", "note",
         // or similar, rather than as part of the same sentence as the error message.
         match self {
-            Self::IterCallError(CallErrorKind::NotCallable, bindings) => {
-                reporter.is_not(format_args!(
-                    "Its `__iter__` attribute has type `{dunder_iter_type}`, which is not callable",
-                    dunder_iter_type = bindings.callable_type().display(db),
-                ));
-            }
-            Self::IterCallError(CallErrorKind::PossiblyNotCallable, bindings)
-                if bindings.is_single() =>
-            {
-                reporter.may_not(format_args!(
-                    "Its `__iter__` attribute (with type `{dunder_iter_type}`) \
-                     may not be callable",
-                    dunder_iter_type = bindings.callable_type().display(db),
-                ));
-            }
-            Self::IterCallError(CallErrorKind::PossiblyNotCallable, bindings) => {
-                reporter.may_not(format_args!(
-                    "Its `__iter__` attribute (with type `{dunder_iter_type}`) \
-                     may not be callable",
-                    dunder_iter_type = bindings.callable_type().display(db),
-                ));
-            }
-            Self::IterCallError(CallErrorKind::BindingError, bindings) if bindings.is_single() => {
-                reporter
-                    .is_not("Its `__iter__` method has an invalid signature")
-                    .info("Expected signature `def __iter__(self): ...`");
-            }
-            Self::IterCallError(CallErrorKind::BindingError, bindings) => {
-                let mut diag =
-                    reporter.may_not("Its `__iter__` method may have an invalid signature");
-                diag.info(format_args!(
-                    "Type of `__iter__` is `{dunder_iter_type}`",
-                    dunder_iter_type = bindings.callable_type().display(db),
-                ));
-                diag.info("Expected signature for `__iter__` is `def __iter__(self): ...`");
+            Self::IterCallError {
+                kind,
+                bindings,
+                mode,
+            } => {
+                let method = if mode.is_async() {
+                    "__aiter__"
+                } else {
+                    "__iter__"
+                };
+
+                match kind {
+                    CallErrorKind::NotCallable => {
+                        reporter.is_not(format_args!(
+                        "Its `{method}` attribute has type `{dunder_iter_type}`, which is not callable",
+                        dunder_iter_type = bindings.callable_type().display(db),
+                    ));
+                    }
+                    CallErrorKind::PossiblyNotCallable => {
+                        reporter.may_not(format_args!(
+                            "Its `{method}` attribute (with type `{dunder_iter_type}`) \
+                             may not be callable",
+                            dunder_iter_type = bindings.callable_type().display(db),
+                        ));
+                    }
+                    CallErrorKind::BindingError => {
+                        if bindings.is_single() {
+                            reporter
+                                .is_not(format_args!(
+                                    "Its `{method}` method has an invalid signature"
+                                ))
+                                .info(format_args!("Expected signature `def {method}(self): ...`"));
+                        } else {
+                            let mut diag = reporter.may_not(format_args!(
+                                "Its `{method}` method may have an invalid signature"
+                            ));
+                            diag.info(format_args!(
+                                "Type of `{method}` is `{dunder_iter_type}`",
+                                dunder_iter_type = bindings.callable_type().display(db),
+                            ));
+                            diag.info(format_args!(
+                                "Expected signature for `{method}` is `def {method}(self): ...`",
+                            ));
+                        }
+                    }
+                }
             }
 
             Self::IterReturnsInvalidIterator {
                 iterator,
-                dunder_next_error,
-            } => match dunder_next_error {
-                CallDunderError::MethodNotAvailable => {
-                    reporter.is_not(format_args!(
-                        "Its `__iter__` method returns an object of type `{iterator_type}`, \
-                     which has no `__next__` method",
+                dunder_error: dunder_next_error,
+                mode,
+            } => {
+                let dunder_iter_name = if mode.is_async() {
+                    "__aiter__"
+                } else {
+                    "__iter__"
+                };
+                let dunder_next_name = if mode.is_async() {
+                    "__anext__"
+                } else {
+                    "__next__"
+                };
+                match dunder_next_error {
+                    CallDunderError::MethodNotAvailable => {
+                        reporter.is_not(format_args!(
+                        "Its `{dunder_iter_name}` method returns an object of type `{iterator_type}`, \
+                         which has no `{dunder_next_name}` method",
                         iterator_type = iterator.display(db),
                     ));
-                }
-                CallDunderError::PossiblyUnbound(_) => {
-                    reporter.may_not(format_args!(
-                        "Its `__iter__` method returns an object of type `{iterator_type}`, \
-                     which may not have a `__next__` method",
-                        iterator_type = iterator.display(db),
-                    ));
-                }
-                CallDunderError::CallError(CallErrorKind::NotCallable, _) => {
-                    reporter.is_not(format_args!(
-                        "Its `__iter__` method returns an object of type `{iterator_type}`, \
-                         which has a `__next__` attribute that is not callable",
-                        iterator_type = iterator.display(db),
-                    ));
-                }
-                CallDunderError::CallError(CallErrorKind::PossiblyNotCallable, _) => {
-                    reporter.may_not(format_args!(
-                        "Its `__iter__` method returns an object of type `{iterator_type}`, \
-                         which has a `__next__` attribute that may not be callable",
-                        iterator_type = iterator.display(db),
-                    ));
-                }
-                CallDunderError::CallError(CallErrorKind::BindingError, bindings)
-                    if bindings.is_single() =>
-                {
-                    reporter
-                        .is_not(format_args!(
-                            "Its `__iter__` method returns an object of type `{iterator_type}`, \
-                             which has an invalid `__next__` method",
+                    }
+                    CallDunderError::PossiblyUnbound(_) => {
+                        reporter.may_not(format_args!(
+                            "Its `{dunder_iter_name}` method returns an object of type `{iterator_type}`, \
+                            which may not have a `{dunder_next_name}` method",
                             iterator_type = iterator.display(db),
-                        ))
-                        .info("Expected signature for `__next__` is `def __next__(self): ...`");
-                }
-                CallDunderError::CallError(CallErrorKind::BindingError, _) => {
-                    reporter
-                        .may_not(format_args!(
-                            "Its `__iter__` method returns an object of type `{iterator_type}`, \
-                             which may have an invalid `__next__` method",
+                        ));
+                    }
+                    CallDunderError::CallError(CallErrorKind::NotCallable, _) => {
+                        reporter.is_not(format_args!(
+                            "Its `{dunder_iter_name}` method returns an object of type `{iterator_type}`, \
+                            which has a `{dunder_next_name}` attribute that is not callable",
                             iterator_type = iterator.display(db),
-                        ))
-                        .info("Expected signature for `__next__` is `def __next__(self): ...`)");
+                        ));
+                    }
+                    CallDunderError::CallError(CallErrorKind::PossiblyNotCallable, _) => {
+                        reporter.may_not(format_args!(
+                            "Its `{dunder_iter_name}` method returns an object of type `{iterator_type}`, \
+                            which has a `{dunder_next_name}` attribute that may not be callable",
+                            iterator_type = iterator.display(db),
+                        ));
+                    }
+                    CallDunderError::CallError(CallErrorKind::BindingError, bindings)
+                        if bindings.is_single() =>
+                    {
+                        reporter
+                            .is_not(format_args!(
+                                "Its `{dunder_iter_name}` method returns an object of type `{iterator_type}`, \
+                                which has an invalid `{dunder_next_name}` method",
+                                iterator_type = iterator.display(db),
+                            ))
+                            .info(format_args!("Expected signature for `{dunder_next_name}` is `def {dunder_next_name}(self): ...`"));
+                    }
+                    CallDunderError::CallError(CallErrorKind::BindingError, _) => {
+                        reporter
+                            .may_not(format_args!(
+                                "Its `{dunder_iter_name}` method returns an object of type `{iterator_type}`, \
+                                which may have an invalid `{dunder_next_name}` method",
+                                iterator_type = iterator.display(db),
+                            ))
+                            .info(format_args!("Expected signature for `{dunder_next_name}` is `def {dunder_next_name}(self): ...`"));
+                    }
                 }
-            },
+            }
 
             Self::PossiblyUnboundIterAndGetitemError {
                 dunder_getitem_error,
@@ -7109,6 +7176,10 @@ impl<'db> IterationError<'db> {
                         );
                 }
             },
+
+            IterationError::UnboundAiterError => {
+                reporter.is_not("It has no `__aiter__` method");
+            }
         }
     }
 }
@@ -7936,7 +8007,7 @@ impl<'db> PEP695TypeAliasType<'db> {
         semantic_index(db, scope.file(db)).expect_single_definition(type_alias_stmt_node)
     }
 
-    #[salsa::tracked(heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(heap_size=get_size2::heap_size)]
     pub(crate) fn value_type(self, db: &'db dyn Db) -> Type<'db> {
         let scope = self.rhs_scope(db);
         let module = parsed_module(db, scope.file(db)).load(db);

crates/ty_python_semantic/src/types/call/arguments.rs

@@ -6,7 +6,7 @@ use ruff_python_ast as ast;
 use crate::Db;
 use crate::types::KnownClass;
 use crate::types::enums::enum_member_literals;
-use crate::types::tuple::{TupleLength, TupleSpec, TupleType};
+use crate::types::tuple::{Tuple, TupleLength, TupleType};
 
 use super::Type;
 
@@ -221,6 +221,34 @@ fn expand_type<'db>(db: &'db dyn Db, ty: Type<'db>) -> Option<Vec<Type<'db>>> {
                 ]);
             }
 
+            // If the class is a fixed-length tuple subtype, we expand it to its elements.
+            if let Some(spec) = instance.class.tuple_spec(db) {
+                return match &*spec {
+                    Tuple::Fixed(fixed_length_tuple) => {
+                        let expanded = fixed_length_tuple
+                            .all_elements()
+                            .map(|element| {
+                                if let Some(expanded) = expand_type(db, *element) {
+                                    Either::Left(expanded.into_iter())
+                                } else {
+                                    Either::Right(std::iter::once(*element))
+                                }
+                            })
+                            .multi_cartesian_product()
+                            .map(|types| TupleType::from_elements(db, types))
+                            .collect::<Vec<_>>();
+
+                        if expanded.len() == 1 {
+                            // There are no elements in the tuple type that can be expanded.
+                            None
+                        } else {
+                            Some(expanded)
+                        }
+                    }
+                    Tuple::Variable(_) => None,
+                };
+            }
+
             let class_literal = instance.class.class_literal(db).0;
 
             if let Some(enum_members) = enum_member_literals(db, class_literal, None) {
@@ -229,32 +257,6 @@ fn expand_type<'db>(db: &'db dyn Db, ty: Type<'db>) -> Option<Vec<Type<'db>>> {
 
             None
         }
-        Type::Tuple(tuple_type) => {
-            // Note: This should only account for tuples of known length, i.e., `tuple[bool, ...]`
-            // should not be expanded here.
-            let tuple = tuple_type.tuple(db);
-            if !matches!(tuple, TupleSpec::Fixed(_)) {
-                return None;
-            }
-            let expanded = tuple
-                .all_elements()
-                .map(|element| {
-                    if let Some(expanded) = expand_type(db, *element) {
-                        Either::Left(expanded.into_iter())
-                    } else {
-                        Either::Right(std::iter::once(*element))
-                    }
-                })
-                .multi_cartesian_product()
-                .map(|types| TupleType::from_elements(db, types))
-                .collect::<Vec<_>>();
-            if expanded.len() == 1 {
-                // There are no elements in the tuple type that can be expanded.
-                None
-            } else {
-                Some(expanded)
-            }
-        }
         Type::Union(union) => Some(union.iter(db).copied().collect()),
         // We don't handle `type[A | B]` here because it's already stored in the expanded form
         // i.e., `type[A] | type[B]` which is handled by the `Type::Union` case.

crates/ty_python_semantic/src/types/call/bind.rs

@@ -1034,7 +1034,7 @@ impl<'db> Bindings<'db> {
                                     );
                                     continue;
                                 };
-                                overload.set_return_type(Type::tuple(TupleType::new(
+                                overload.set_return_type(Type::tuple(db, TupleType::new(
                                     db,
                                     tuple_spec.as_ref(),
                                 )));

crates/ty_python_semantic/src/types/class.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::hash::BuildHasherDefault;
 use std::sync::{LazyLock, Mutex};
 
@@ -19,15 +20,15 @@ use crate::types::function::{DataclassTransformerParams, KnownFunction};
 use crate::types::generics::{GenericContext, Specialization, walk_specialization};
 use crate::types::infer::nearest_enclosing_class;
 use crate::types::signatures::{CallableSignature, Parameter, Parameters, Signature};
-use crate::types::tuple::TupleType;
+use crate::types::tuple::{TupleSpec, TupleType};
 use crate::types::{
     BareTypeAliasType, Binding, BoundSuperError, BoundSuperType, CallableType, DataclassParams,
-    DeprecatedInstance, DynamicType, KnownInstanceType, TypeAliasType, TypeMapping, TypeRelation,
-    TypeTransformer, TypeVarBoundOrConstraints, TypeVarInstance, TypeVarKind, declaration_type,
-    infer_definition_types,
+    DeprecatedInstance, DynamicType, KnownInstanceType, NominalInstanceType, TypeAliasType,
+    TypeMapping, TypeRelation, TypeTransformer, TypeVarBoundOrConstraints, TypeVarInstance,
+    TypeVarKind, declaration_type, infer_definition_types,
 };
 use crate::{
-    Db, FxOrderSet, KnownModule, Program,
+    Db, FxIndexMap, FxOrderSet, KnownModule, Program,
     module_resolver::file_to_module,
     place::{
         Boundness, LookupError, LookupResult, Place, PlaceAndQualifiers, class_symbol,
@@ -574,8 +575,25 @@ impl<'db> ClassType<'db> {
     /// directly. Use [`ClassType::class_member`] if you require a method that will
     /// traverse through the MRO until it finds the member.
     pub(super) fn own_class_member(self, db: &'db dyn Db, name: &str) -> PlaceAndQualifiers<'db> {
+        fn synthesize_getitem_overload_signature<'db>(
+            index_annotation: Type<'db>,
+            return_annotation: Type<'db>,
+        ) -> Signature<'db> {
+            let self_parameter = Parameter::positional_only(Some(Name::new_static("self")));
+            let index_parameter = Parameter::positional_only(Some(Name::new_static("index")))
+                .with_annotated_type(index_annotation);
+            let parameters = Parameters::new([self_parameter, index_parameter]);
+            Signature::new(parameters, Some(return_annotation))
+        }
+
         let (class_literal, specialization) = self.class_literal(db);
 
+        let fallback_member_lookup = || {
+            class_literal
+                .own_class_member(db, specialization, name)
+                .map_type(|ty| ty.apply_optional_specialization(db, specialization))
+        };
+
         let synthesize_simple_tuple_method = |return_type| {
             let parameters =
                 Parameters::new([Parameter::positional_only(Some(Name::new_static("self")))
@@ -606,6 +624,162 @@ impl<'db> ClassType<'db> {
                 synthesize_simple_tuple_method(return_type)
             }
 
+            "__getitem__" if class_literal.is_tuple(db) => {
+                specialization
+                    .map(|spec| {
+                        let tuple = spec.tuple(db);
+
+                        let mut element_type_to_indices: FxIndexMap<Type<'db>, Vec<i64>> =
+                            FxIndexMap::default();
+
+                        match tuple {
+                            // E.g. for `tuple[int, str]`, we will generate the following overloads:
+                            //
+                            //    __getitem__(self, index: Literal[0, -2], /) -> int
+                            //    __getitem__(self, index: Literal[1, -1], /) -> str
+                            //
+                            TupleSpec::Fixed(fixed_length_tuple) => {
+                                let tuple_length = fixed_length_tuple.len();
+
+                                for (index, ty) in fixed_length_tuple.elements().enumerate() {
+                                    let entry = element_type_to_indices.entry(*ty).or_default();
+                                    if let Ok(index) = i64::try_from(index) {
+                                        entry.push(index);
+                                    }
+                                    if let Ok(index) = i64::try_from(tuple_length - index) {
+                                        entry.push(0 - index);
+                                    }
+                                }
+                            }
+
+                            // E.g. for `tuple[str, *tuple[float, ...], bytes, range]`, we will generate the following overloads:
+                            //
+                            //    __getitem__(self, index: Literal[0], /) -> str
+                            //    __getitem__(self, index: Literal[1], /) -> float | bytes
+                            //    __getitem__(self, index: Literal[2], /) -> float | bytes | range
+                            //    __getitem__(self, index: Literal[-1], /) -> range
+                            //    __getitem__(self, index: Literal[-2], /) -> bytes
+                            //    __getitem__(self, index: Literal[-3], /) -> float | str
+                            //
+                            TupleSpec::Variable(variable_length_tuple) => {
+                                for (index, ty) in variable_length_tuple.prefix.iter().enumerate() {
+                                    if let Ok(index) = i64::try_from(index) {
+                                        element_type_to_indices.entry(*ty).or_default().push(index);
+                                    }
+
+                                    let one_based_index = index + 1;
+
+                                    if let Ok(i) = i64::try_from(
+                                        variable_length_tuple.suffix.len() + one_based_index,
+                                    ) {
+                                        let overload_return = UnionType::from_elements(
+                                            db,
+                                            std::iter::once(variable_length_tuple.variable).chain(
+                                                variable_length_tuple
+                                                    .prefix
+                                                    .iter()
+                                                    .rev()
+                                                    .take(one_based_index)
+                                                    .copied(),
+                                            ),
+                                        );
+                                        element_type_to_indices
+                                            .entry(overload_return)
+                                            .or_default()
+                                            .push(0 - i);
+                                    }
+                                }
+
+                                for (index, ty) in
+                                    variable_length_tuple.suffix.iter().rev().enumerate()
+                                {
+                                    if let Some(index) =
+                                        index.checked_add(1).and_then(|i| i64::try_from(i).ok())
+                                    {
+                                        element_type_to_indices
+                                            .entry(*ty)
+                                            .or_default()
+                                            .push(0 - index);
+                                    }
+
+                                    if let Ok(i) =
+                                        i64::try_from(variable_length_tuple.prefix.len() + index)
+                                    {
+                                        let overload_return = UnionType::from_elements(
+                                            db,
+                                            std::iter::once(variable_length_tuple.variable).chain(
+                                                variable_length_tuple
+                                                    .suffix
+                                                    .iter()
+                                                    .take(index + 1)
+                                                    .copied(),
+                                            ),
+                                        );
+                                        element_type_to_indices
+                                            .entry(overload_return)
+                                            .or_default()
+                                            .push(i);
+                                    }
+                                }
+                            }
+                        }
+
+                        let all_elements_unioned =
+                            UnionType::from_elements(db, tuple.all_elements());
+
+                        let mut overload_signatures =
+                            Vec::with_capacity(element_type_to_indices.len().saturating_add(2));
+
+                        overload_signatures.extend(element_type_to_indices.into_iter().filter_map(
+                            |(return_type, mut indices)| {
+                                if return_type.is_equivalent_to(db, all_elements_unioned) {
+                                    return None;
+                                }
+
+                                // Sorting isn't strictly required, but leads to nicer `reveal_type` output
+                                indices.sort_unstable();
+
+                                let index_annotation = UnionType::from_elements(
+                                    db,
+                                    indices.into_iter().map(Type::IntLiteral),
+                                );
+
+                                Some(synthesize_getitem_overload_signature(
+                                    index_annotation,
+                                    return_type,
+                                ))
+                            },
+                        ));
+
+                        // Fallback overloads: for `tuple[int, str]`, we will generate the following overloads:
+                        //
+                        //    __getitem__(self, index: int, /) -> int | str
+                        //    __getitem__(self, index: slice[Any, Any, Any], /) -> tuple[int | str, ...]
+                        //
+                        // and for `tuple[str, *tuple[float, ...], bytes]`, we will generate the following overloads:
+                        //
+                        //    __getitem__(self, index: int, /) -> str | float | bytes
+                        //    __getitem__(self, index: slice[Any, Any, Any], /) -> tuple[str | float | bytes, ...]
+                        //
+                        overload_signatures.push(synthesize_getitem_overload_signature(
+                            KnownClass::SupportsIndex.to_instance(db),
+                            all_elements_unioned,
+                        ));
+
+                        overload_signatures.push(synthesize_getitem_overload_signature(
+                            KnownClass::Slice.to_instance(db),
+                            TupleType::homogeneous(db, all_elements_unioned),
+                        ));
+
+                        let getitem_signature =
+                            CallableSignature::from_overloads(overload_signatures);
+                        let getitem_type =
+                            Type::Callable(CallableType::new(db, getitem_signature, true));
+                        Place::bound(getitem_type).into()
+                    })
+                    .unwrap_or_else(fallback_member_lookup)
+            }
+
             // ```py
             // class tuple:
             //     @overload
@@ -672,9 +846,7 @@ impl<'db> ClassType<'db> {
                 Place::bound(synthesized_dunder).into()
             }
 
-            _ => class_literal
-                .own_class_member(db, specialization, name)
-                .map_type(|ty| ty.apply_optional_specialization(db, specialization)),
+            _ => fallback_member_lookup(),
         }
     }
 
@@ -842,6 +1014,59 @@ impl<'db> ClassType<'db> {
             }
         }
     }
+
+    /// If this class is `tuple`, a specialization of `tuple` (`tuple[int, str]`, etc.),
+    /// *or a subclass of `tuple`, or a subclass of a specialization of `tuple`*,
+    /// return its tuple specification.
+    pub(super) fn tuple_spec(self, db: &'db dyn Db) -> Option<Cow<'db, TupleSpec<'db>>> {
+        self.iter_mro(db)
+            .filter_map(ClassBase::into_class)
+            .find_map(|class| class.own_tuple_spec(db))
+    }
+
+    /// If this class is `tuple` or a specialization of `tuple` (`tuple[int, str]`, etc.),
+    /// return its tuple specification.
+    ///
+    /// You usually don't want to use this method directly, because you usually want to consider
+    /// any subclass of a certain tuple type in the same way as that tuple type itself.
+    /// Use [`ClassType::tuple_spec`] instead.
+    pub(super) fn own_tuple_spec(self, db: &'db dyn Db) -> Option<Cow<'db, TupleSpec<'db>>> {
+        let (class_literal, specialization) = self.class_literal(db);
+        match class_literal.known(db)? {
+            KnownClass::Tuple => Some(
+                specialization
+                    .map(|spec| Cow::Borrowed(spec.tuple(db)))
+                    .unwrap_or_else(|| Cow::Owned(TupleSpec::homogeneous(Type::unknown()))),
+            ),
+            KnownClass::VersionInfo => {
+                let python_version = Program::get(db).python_version(db);
+                let int_instance_ty = KnownClass::Int.to_instance(db);
+
+                // TODO: just grab this type from typeshed (it's a `sys._ReleaseLevel` type alias there)
+                let release_level_ty = {
+                    let elements: Box<[Type<'db>]> = ["alpha", "beta", "candidate", "final"]
+                        .iter()
+                        .map(|level| Type::string_literal(db, level))
+                        .collect();
+
+                    // For most unions, it's better to go via `UnionType::from_elements` or use `UnionBuilder`;
+                    // those techniques ensure that union elements are deduplicated and unions are eagerly simplified
+                    // into other types where necessary. Here, however, we know that there are no duplicates
+                    // in this union, so it's probably more efficient to use `UnionType::new()` directly.
+                    Type::Union(UnionType::new(db, elements))
+                };
+
+                Some(Cow::Owned(TupleSpec::from_elements([
+                    Type::IntLiteral(python_version.major.into()),
+                    Type::IntLiteral(python_version.minor.into()),
+                    int_instance_ty,
+                    release_level_ty,
+                    int_instance_ty,
+                ])))
+            }
+            _ => None,
+        }
+    }
 }
 
 impl<'db> From<GenericAlias<'db>> for ClassType<'db> {
@@ -979,7 +1204,7 @@ impl<'db> ClassLiteral<'db> {
         self.pep695_generic_context(db).is_some()
     }
 
-    #[salsa::tracked(cycle_fn=pep695_generic_context_cycle_recover, cycle_initial=pep695_generic_context_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(cycle_fn=pep695_generic_context_cycle_recover, cycle_initial=pep695_generic_context_cycle_initial, heap_size=get_size2::heap_size)]
     pub(crate) fn pep695_generic_context(self, db: &'db dyn Db) -> Option<GenericContext<'db>> {
         let scope = self.body_scope(db);
         let parsed = parsed_module(db, scope.file(db)).load(db);
@@ -1089,7 +1314,7 @@ impl<'db> ClassLiteral<'db> {
     ///
     /// Were this not a salsa query, then the calling query
     /// would depend on the class's AST and rerun for every change in that file.
-    #[salsa::tracked(returns(deref), cycle_fn=explicit_bases_cycle_recover, cycle_initial=explicit_bases_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(returns(deref), cycle_fn=explicit_bases_cycle_recover, cycle_initial=explicit_bases_cycle_initial, heap_size=get_size2::heap_size)]
     pub(super) fn explicit_bases(self, db: &'db dyn Db) -> Box<[Type<'db>]> {
         tracing::trace!("ClassLiteral::explicit_bases_query: {}", self.name(db));
 
@@ -1165,7 +1390,7 @@ impl<'db> ClassLiteral<'db> {
     }
 
     /// Return the types of the decorators on this class
-    #[salsa::tracked(returns(deref), heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(returns(deref), heap_size=get_size2::heap_size)]
     fn decorators(self, db: &'db dyn Db) -> Box<[Type<'db>]> {
         tracing::trace!("ClassLiteral::decorators: {}", self.name(db));
 
@@ -1214,7 +1439,7 @@ impl<'db> ClassLiteral<'db> {
     /// attribute on a class at runtime.
     ///
     /// [method resolution order]: https://docs.python.org/3/glossary.html#term-method-resolution-order
-    #[salsa::tracked(returns(as_ref), cycle_fn=try_mro_cycle_recover, cycle_initial=try_mro_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(returns(as_ref), cycle_fn=try_mro_cycle_recover, cycle_initial=try_mro_cycle_initial, heap_size=get_size2::heap_size)]
     pub(super) fn try_mro(
         self,
         db: &'db dyn Db,
@@ -1294,7 +1519,7 @@ impl<'db> ClassLiteral<'db> {
     #[salsa::tracked(
         cycle_fn=try_metaclass_cycle_recover,
         cycle_initial=try_metaclass_cycle_initial,
-        heap_size=get_size2::GetSize::get_heap_size,
+        heap_size=get_size2::heap_size,
     )]
     pub(super) fn try_metaclass(
         self,
@@ -1596,7 +1821,10 @@ impl<'db> ClassLiteral<'db> {
 
         let field_policy = CodeGeneratorKind::from_class(db, self)?;
 
-        let signature_from_fields = |mut parameters: Vec<_>| {
+        let instance_ty =
+            Type::instance(db, self.apply_optional_specialization(db, specialization));
+
+        let signature_from_fields = |mut parameters: Vec<_>, return_ty: Option<Type<'db>>| {
             let mut kw_only_field_seen = false;
             for (
                 field_name,
@@ -1669,21 +1897,26 @@ impl<'db> ClassLiteral<'db> {
                     }
                 }
 
-                let mut parameter = if kw_only_field_seen {
+                let mut parameter = if kw_only_field_seen || name == "__replace__" {
                     Parameter::keyword_only(field_name)
                 } else {
                     Parameter::positional_or_keyword(field_name)
                 }
                 .with_annotated_type(field_ty);
 
-                if let Some(default_ty) = default_ty {
+                if name == "__replace__" {
+                    // When replacing, we know there is a default value for the field
+                    // (the value that is currently assigned to the field)
+                    // assume this to be the declared type of the field
+                    parameter = parameter.with_default_type(field_ty);
+                } else if let Some(default_ty) = default_ty {
                     parameter = parameter.with_default_type(default_ty);
                 }
 
                 parameters.push(parameter);
             }
 
-            let mut signature = Signature::new(Parameters::new(parameters), Some(Type::none(db)));
+            let mut signature = Signature::new(Parameters::new(parameters), return_ty);
             signature.inherited_generic_context = self.generic_context(db);
             Some(CallableType::function_like(db, signature))
         };
@@ -1701,16 +1934,13 @@ impl<'db> ClassLiteral<'db> {
 
                 let self_parameter = Parameter::positional_or_keyword(Name::new_static("self"))
                     // TODO: could be `Self`.
-                    .with_annotated_type(Type::instance(
-                        db,
-                        self.apply_optional_specialization(db, specialization),
-                    ));
-                signature_from_fields(vec![self_parameter])
+                    .with_annotated_type(instance_ty);
+                signature_from_fields(vec![self_parameter], Some(Type::none(db)))
             }
             (CodeGeneratorKind::NamedTuple, "__new__") => {
                 let cls_parameter = Parameter::positional_or_keyword(Name::new_static("cls"))
                     .with_annotated_type(KnownClass::Type.to_instance(db));
-                signature_from_fields(vec![cls_parameter])
+                signature_from_fields(vec![cls_parameter], Some(Type::none(db)))
             }
             (CodeGeneratorKind::DataclassLike, "__lt__" | "__le__" | "__gt__" | "__ge__") => {
                 if !has_dataclass_param(DataclassParams::ORDER) {
@@ -1721,16 +1951,10 @@ impl<'db> ClassLiteral<'db> {
                     Parameters::new([
                         Parameter::positional_or_keyword(Name::new_static("self"))
                             // TODO: could be `Self`.
-                            .with_annotated_type(Type::instance(
-                                db,
-                                self.apply_optional_specialization(db, specialization),
-                            )),
+                            .with_annotated_type(instance_ty),
                         Parameter::positional_or_keyword(Name::new_static("other"))
                             // TODO: could be `Self`.
-                            .with_annotated_type(Type::instance(
-                                db,
-                                self.apply_optional_specialization(db, specialization),
-                            )),
+                            .with_annotated_type(instance_ty),
                     ]),
                     Some(KnownClass::Bool.to_instance(db)),
                 );
@@ -1745,15 +1969,20 @@ impl<'db> ClassLiteral<'db> {
                     .place
                     .ignore_possibly_unbound()
             }
+            (CodeGeneratorKind::DataclassLike, "__replace__")
+                if Program::get(db).python_version(db) >= PythonVersion::PY313 =>
+            {
+                let self_parameter = Parameter::positional_or_keyword(Name::new_static("self"))
+                    .with_annotated_type(instance_ty);
+
+                signature_from_fields(vec![self_parameter], Some(instance_ty))
+            }
             (CodeGeneratorKind::DataclassLike, "__setattr__") => {
                 if has_dataclass_param(DataclassParams::FROZEN) {
                     let signature = Signature::new(
                         Parameters::new([
                             Parameter::positional_or_keyword(Name::new_static("self"))
-                                .with_annotated_type(Type::instance(
-                                    db,
-                                    self.apply_optional_specialization(db, specialization),
-                                )),
+                                .with_annotated_type(instance_ty),
                             Parameter::positional_or_keyword(Name::new_static("name")),
                             Parameter::positional_or_keyword(Name::new_static("value")),
                         ]),
@@ -2402,7 +2631,7 @@ impl<'db> ClassLiteral<'db> {
     ///
     /// A class definition like this will fail at runtime,
     /// but we must be resilient to it or we could panic.
-    #[salsa::tracked(cycle_fn=inheritance_cycle_recover, cycle_initial=inheritance_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+    #[salsa::tracked(cycle_fn=inheritance_cycle_recover, cycle_initial=inheritance_cycle_initial, heap_size=get_size2::heap_size)]
     pub(super) fn inheritance_cycle(self, db: &'db dyn Db) -> Option<InheritanceCycle> {
         /// Return `true` if the class is cyclically defined.
         ///
@@ -2610,10 +2839,13 @@ pub enum KnownClass {
     UnionType,
     GeneratorType,
     AsyncGeneratorType,
+    CoroutineType,
     // Typeshed
     NoneType, // Part of `types` for Python >= 3.10
     // Typing
     Any,
+    Awaitable,
+    Generator,
     Deprecated,
     StdlibAlias,
     SpecialForm,
@@ -2685,7 +2917,8 @@ impl KnownClass {
             | Self::UnionType
             | Self::GeneratorType
             | Self::AsyncGeneratorType
-            | Self::MethodWrapperType => Truthiness::AlwaysTrue,
+            | Self::MethodWrapperType
+            | Self::CoroutineType => Truthiness::AlwaysTrue,
 
             Self::NoneType => Truthiness::AlwaysFalse,
 
@@ -2736,6 +2969,8 @@ impl KnownClass {
             | Self::NotImplementedType
             | Self::Staticmethod
             | Self::Classmethod
+            | Self::Awaitable
+            | Self::Generator
             | Self::Deprecated
             | Self::Field
             | Self::KwOnly
@@ -2801,12 +3036,15 @@ impl KnownClass {
             | Self::InitVar
             | Self::VersionInfo
             | Self::Bool
-            | Self::NoneType => false,
+            | Self::NoneType
+            | Self::CoroutineType => false,
 
             // Anything with a *runtime* MRO (N.B. sometimes different from the MRO that typeshed gives!)
             // with length >2, or anything that is implemented in pure Python, is not a solid base.
             Self::ABCMeta
             | Self::Any
+            | Self::Awaitable
+            | Self::Generator
             | Self::Enum
             | Self::EnumType
             | Self::Auto
@@ -2855,6 +3093,8 @@ impl KnownClass {
             | KnownClass::ExceptionGroup
             | KnownClass::Staticmethod
             | KnownClass::Classmethod
+            | KnownClass::Awaitable
+            | KnownClass::Generator
             | KnownClass::Deprecated
             | KnownClass::Super
             | KnownClass::Enum
@@ -2872,6 +3112,7 @@ impl KnownClass {
             | KnownClass::UnionType
             | KnownClass::GeneratorType
             | KnownClass::AsyncGeneratorType
+            | KnownClass::CoroutineType
             | KnownClass::NoneType
             | KnownClass::Any
             | KnownClass::StdlibAlias
@@ -2917,7 +3158,11 @@ impl KnownClass {
     /// 2. It's probably more performant.
     const fn is_protocol(self) -> bool {
         match self {
-            Self::SupportsIndex | Self::Iterable | Self::Iterator => true,
+            Self::SupportsIndex
+            | Self::Iterable
+            | Self::Iterator
+            | Self::Awaitable
+            | Self::Generator => true,
 
             Self::Any
             | Self::Bool
@@ -2946,6 +3191,7 @@ impl KnownClass {
             | Self::GenericAlias
             | Self::GeneratorType
             | Self::AsyncGeneratorType
+            | Self::CoroutineType
             | Self::ModuleType
             | Self::FunctionType
             | Self::MethodType
@@ -3011,6 +3257,8 @@ impl KnownClass {
             Self::ExceptionGroup => "ExceptionGroup",
             Self::Staticmethod => "staticmethod",
             Self::Classmethod => "classmethod",
+            Self::Awaitable => "Awaitable",
+            Self::Generator => "Generator",
             Self::Deprecated => "deprecated",
             Self::GenericAlias => "GenericAlias",
             Self::ModuleType => "ModuleType",
@@ -3021,6 +3269,7 @@ impl KnownClass {
             Self::WrapperDescriptorType => "WrapperDescriptorType",
             Self::GeneratorType => "GeneratorType",
             Self::AsyncGeneratorType => "AsyncGeneratorType",
+            Self::CoroutineType => "CoroutineType",
             Self::NamedTuple => "NamedTuple",
             Self::NoneType => "NoneType",
             Self::SpecialForm => "_SpecialForm",
@@ -3281,11 +3530,14 @@ impl KnownClass {
             | Self::MethodType
             | Self::GeneratorType
             | Self::AsyncGeneratorType
+            | Self::CoroutineType
             | Self::MethodWrapperType
             | Self::UnionType
             | Self::WrapperDescriptorType => KnownModule::Types,
             Self::NoneType => KnownModule::Typeshed,
             Self::Any
+            | Self::Awaitable
+            | Self::Generator
             | Self::SpecialForm
             | Self::TypeVar
             | Self::NamedTuple
@@ -3366,12 +3618,15 @@ impl KnownClass {
             | Self::ExceptionGroup
             | Self::Staticmethod
             | Self::Classmethod
+            | Self::Awaitable
+            | Self::Generator
             | Self::Deprecated
             | Self::GenericAlias
             | Self::ModuleType
             | Self::FunctionType
             | Self::GeneratorType
             | Self::AsyncGeneratorType
+            | Self::CoroutineType
             | Self::MethodType
             | Self::MethodWrapperType
             | Self::WrapperDescriptorType
@@ -3443,6 +3698,7 @@ impl KnownClass {
             | Self::WrapperDescriptorType
             | Self::GeneratorType
             | Self::AsyncGeneratorType
+            | Self::CoroutineType
             | Self::SpecialForm
             | Self::ChainMap
             | Self::Counter
@@ -3457,6 +3713,8 @@ impl KnownClass {
             | Self::ExceptionGroup
             | Self::Staticmethod
             | Self::Classmethod
+            | Self::Awaitable
+            | Self::Generator
             | Self::Deprecated
             | Self::TypeVar
             | Self::ParamSpec
@@ -3513,12 +3771,15 @@ impl KnownClass {
             "ExceptionGroup" => Self::ExceptionGroup,
             "staticmethod" => Self::Staticmethod,
             "classmethod" => Self::Classmethod,
+            "Awaitable" => Self::Awaitable,
+            "Generator" => Self::Generator,
             "deprecated" => Self::Deprecated,
             "GenericAlias" => Self::GenericAlias,
             "NoneType" => Self::NoneType,
             "ModuleType" => Self::ModuleType,
             "GeneratorType" => Self::GeneratorType,
             "AsyncGeneratorType" => Self::AsyncGeneratorType,
+            "CoroutineType" => Self::CoroutineType,
             "FunctionType" => Self::FunctionType,
             "MethodType" => Self::MethodType,
             "UnionType" => Self::UnionType,
@@ -3623,11 +3884,14 @@ impl KnownClass {
             | Self::UnionType
             | Self::GeneratorType
             | Self::AsyncGeneratorType
+            | Self::CoroutineType
             | Self::WrapperDescriptorType
             | Self::Field
             | Self::KwOnly
             | Self::InitVar
-            | Self::NamedTupleFallback => module == self.canonical_module(db),
+            | Self::NamedTupleFallback
+            | Self::Awaitable
+            | Self::Generator => module == self.canonical_module(db),
             Self::NoneType => matches!(module, KnownModule::Typeshed | KnownModule::Types),
             Self::SpecialForm
             | Self::TypeVar
@@ -4003,14 +4267,14 @@ pub(crate) struct SliceLiteral {
     pub(crate) step: Option<i32>,
 }
 
-impl<'db> Type<'db> {
-    /// If this type represents a valid slice literal, returns a [`SliceLiteral`] describing it.
+impl<'db> ClassType<'db> {
+    /// If this class is a specialization of `slice`, returns a [`SliceLiteral`] describing it.
     /// Otherwise returns `None`.
     ///
-    /// The type must be a specialization of the `slice` builtin type, where the specialized
-    /// typevars are statically known integers or `None`.
+    /// The specialization must be one in which the typevars are solved as being statically known
+    /// integers or `None`.
     pub(crate) fn slice_literal(self, db: &'db dyn Db) -> Option<SliceLiteral> {
-        let ClassType::Generic(alias) = self.into_nominal_instance()?.class else {
+        let ClassType::Generic(alias) = self else {
             return None;
         };
         if !alias.origin(db).is_known(db, KnownClass::Slice) {
@@ -4103,16 +4367,14 @@ impl SlotsKind {
 
         match slots_ty {
             // __slots__ = ("a", "b")
-            Type::Tuple(tuple) => {
-                let tuple = tuple.tuple(db);
-                if tuple.is_variadic() {
-                    Self::Dynamic
-                } else if tuple.is_empty() {
-                    Self::Empty
-                } else {
-                    Self::NotEmpty
-                }
-            }
+            Type::NominalInstance(NominalInstanceType { class, .. }) => match class
+                .tuple_spec(db)
+                .and_then(|spec| spec.len().into_fixed_length())
+            {
+                Some(0) => Self::Empty,
+                Some(_) => Self::NotEmpty,
+                None => Self::Dynamic,
+            },
 
             // __slots__ = "abc"  # Same as `("abc",)`
             Type::StringLiteral(_) => Self::NotEmpty,

crates/ty_python_semantic/src/types/class_base.rs

@@ -151,7 +151,6 @@ impl<'db> ClassBase<'db> {
             | Type::EnumLiteral(_)
             | Type::StringLiteral(_)
             | Type::LiteralString
-            | Type::Tuple(_)
             | Type::ModuleLiteral(_)
             | Type::TypeVar(_)
             | Type::BoundSuper(_)

crates/ty_python_semantic/src/types/display.rs

@@ -76,6 +76,11 @@ impl Display for DisplayRepresentation<'_> {
                 match (instance.class, instance.class.known(self.db)) {
                     (_, Some(KnownClass::NoneType)) => f.write_str("None"),
                     (_, Some(KnownClass::NoDefaultType)) => f.write_str("NoDefault"),
+                    (ClassType::Generic(alias), Some(KnownClass::Tuple)) => alias
+                        .specialization(self.db)
+                        .tuple(self.db)
+                        .display(self.db)
+                        .fmt(f),
                     (ClassType::NonGeneric(class), _) => f.write_str(class.name(self.db)),
                     (ClassType::Generic(alias), _) => alias.display(self.db).fmt(f),
                 }
@@ -201,7 +206,6 @@ impl Display for DisplayRepresentation<'_> {
                     name = enum_literal.name(self.db),
                 )
             }
-            Type::Tuple(specialization) => specialization.tuple(self.db).display(self.db).fmt(f),
             Type::TypeVar(typevar) => f.write_str(typevar.name(self.db)),
             Type::AlwaysTruthy => f.write_str("AlwaysTruthy"),
             Type::AlwaysFalsy => f.write_str("AlwaysFalsy"),

crates/ty_python_semantic/src/types/enums.rs

@@ -53,7 +53,7 @@ fn enum_metadata_cycle_initial(_db: &dyn Db, _class: ClassLiteral<'_>) -> Option
 
 /// List all members of an enum.
 #[allow(clippy::ref_option, clippy::unnecessary_wraps)]
-#[salsa::tracked(returns(as_ref), cycle_fn=enum_metadata_cycle_recover, cycle_initial=enum_metadata_cycle_initial, heap_size=get_size2::GetSize::get_heap_size)]
+#[salsa::tracked(returns(as_ref), cycle_fn=enum_metadata_cycle_recover, cycle_initial=enum_metadata_cycle_initial, heap_size=get_size2::heap_size)]
 pub(crate) fn enum_metadata<'db>(
     db: &'db dyn Db,
     class: ClassLiteral<'db>,