prefer declared type of generic classes

## Summary

The solver is currently order-dependent, and will choose a supertype
over the exact type if it appears earlier in the list of constraints. We
could be smarter and try to choose the most precise subtype, but I
imagine this is something the new constraint solver will fix anyways,
and this fixes the issue showing up on
https://github.com/astral-sh/ruff/pull/21070.

CHANGELOG.md

@@ -1,5 +1,60 @@
 # Changelog
 
+## 0.14.3
+
+Released on 2025-10-30.
+
+### Preview features
+
+- Respect `--output-format` with `--watch` ([#21097](https://github.com/astral-sh/ruff/pull/21097))
+- \[`pydoclint`\] Fix false positive on explicit exception re-raising (`DOC501`, `DOC502`) ([#21011](https://github.com/astral-sh/ruff/pull/21011))
+- \[`pyflakes`\] Revert to stable behavior if imports for module lie in alternate branches for `F401` ([#20878](https://github.com/astral-sh/ruff/pull/20878))
+- \[`pylint`\] Implement `stop-iteration-return` (`PLR1708`) ([#20733](https://github.com/astral-sh/ruff/pull/20733))
+- \[`ruff`\] Add support for additional eager conversion patterns (`RUF065`) ([#20657](https://github.com/astral-sh/ruff/pull/20657))
+
+### Bug fixes
+
+- Fix finding keyword range for clause header after statement ending with semicolon ([#21067](https://github.com/astral-sh/ruff/pull/21067))
+- Fix syntax error false positive on nested alternative patterns ([#21104](https://github.com/astral-sh/ruff/pull/21104))
+- \[`ISC001`\] Fix panic when string literals are unclosed ([#21034](https://github.com/astral-sh/ruff/pull/21034))
+- \[`flake8-django`\] Apply `DJ001` to annotated fields ([#20907](https://github.com/astral-sh/ruff/pull/20907))
+- \[`flake8-pyi`\] Fix `PYI034` to not trigger on metaclasses (`PYI034`) ([#20881](https://github.com/astral-sh/ruff/pull/20881))
+- \[`flake8-type-checking`\] Fix `TC003` false positive with `future-annotations` ([#21125](https://github.com/astral-sh/ruff/pull/21125))
+- \[`pyflakes`\] Fix false positive for `__class__` in lambda expressions within class definitions (`F821`) ([#20564](https://github.com/astral-sh/ruff/pull/20564))
+- \[`pyupgrade`\] Fix false positive for `TypeVar` with default on Python \<3.13 (`UP046`,`UP047`) ([#21045](https://github.com/astral-sh/ruff/pull/21045))
+
+### Rule changes
+
+- Add missing docstring sections to the numpy list ([#20931](https://github.com/astral-sh/ruff/pull/20931))
+- \[`airflow`\] Extend `airflow.models..Param` check (`AIR311`) ([#21043](https://github.com/astral-sh/ruff/pull/21043))
+- \[`airflow`\] Warn that `airflow....DAG.create_dagrun` has been removed (`AIR301`) ([#21093](https://github.com/astral-sh/ruff/pull/21093))
+- \[`refurb`\] Preserve digit separators in `Decimal` constructor (`FURB157`) ([#20588](https://github.com/astral-sh/ruff/pull/20588))
+
+### Server
+
+- Avoid sending an unnecessary "clear diagnostics" message for clients supporting pull diagnostics ([#21105](https://github.com/astral-sh/ruff/pull/21105))
+
+### Documentation
+
+- \[`flake8-bandit`\] Fix correct example for `S308` ([#21128](https://github.com/astral-sh/ruff/pull/21128))
+
+### Other changes
+
+- Clearer error message when `line-length` goes beyond threshold ([#21072](https://github.com/astral-sh/ruff/pull/21072))
+
+### Contributors
+
+- [@danparizher](https://github.com/danparizher)
+- [@jvacek](https://github.com/jvacek)
+- [@ntBre](https://github.com/ntBre)
+- [@augustelalande](https://github.com/augustelalande)
+- [@prakhar1144](https://github.com/prakhar1144)
+- [@TaKO8Ki](https://github.com/TaKO8Ki)
+- [@dylwil3](https://github.com/dylwil3)
+- [@fatelei](https://github.com/fatelei)
+- [@ShaharNaveh](https://github.com/ShaharNaveh)
+- [@Lee-W](https://github.com/Lee-W)
+
 ## 0.14.2
 
 Released on 2025-10-23.

Cargo.lock

@@ -243,7 +243,7 @@ dependencies = [
  "bitflags 2.9.4",
  "cexpr",
  "clang-sys",
- "itertools 0.10.5",
+ "itertools 0.13.0",
  "log",
  "prettyplease",
  "proc-macro2",
@@ -633,7 +633,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "117725a109d387c937a1533ce01b450cbde6b88abceea8473c4d7a85853cda3c"
 dependencies = [
  "lazy_static",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -642,7 +642,7 @@ version = "3.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fde0e0ec90c9dfb3b4b1a0891a7dcd0e2bffde2f7efed5fe7c9bb00e5bfb915e"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1007,7 +1007,7 @@ dependencies = [
  "libc",
  "option-ext",
  "redox_users",
- "windows-sys 0.60.2",
+ "windows-sys 0.61.0",
 ]
 
 [[package]]
@@ -1093,7 +1093,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.0",
 ]
 
 [[package]]
@@ -1115,13 +1115,12 @@ dependencies = [
 
 [[package]]
 name = "etcetera"
-version = "0.10.0"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26c7b13d0780cb82722fd59f6f57f925e143427e4a75313a6c77243bf5326ae6"
+checksum = "de48cc4d1c1d97a20fd819def54b890cadde72ed3ad0c614822a0a433361be96"
 dependencies = [
  "cfg-if",
- "home",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.0",
 ]
 
 [[package]]
@@ -1366,15 +1365,6 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc0fef456e4baa96da950455cd02c081ca953b141298e41db3fc7e36b1da849c"
 
-[[package]]
-name = "home"
-version = "0.5.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "589533453244b0995c858700322199b2becb13b627df2851f64a2775d024abcf"
-dependencies = [
- "windows-sys 0.59.0",
-]
-
 [[package]]
 name = "html-escape"
 version = "0.2.13"
@@ -1563,7 +1553,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4b0f83760fb341a774ed326568e19f5a863af4a952def8c39f9ab92fd95b88e5"
 dependencies = [
  "equivalent",
- "hashbrown 0.15.5",
+ "hashbrown 0.16.0",
  "serde",
  "serde_core",
 ]
@@ -1690,7 +1680,7 @@ checksum = "e04d7f318608d35d4b61ddd75cbdaee86b023ebe2bd5a66ee0915f0bf93095a9"
 dependencies = [
  "hermit-abi",
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1754,7 +1744,7 @@ dependencies = [
  "portable-atomic",
  "portable-atomic-util",
  "serde",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -2835,7 +2825,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "anyhow",
  "argfile",
@@ -3092,7 +3082,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_linter"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "aho-corasick",
  "anyhow",
@@ -3447,7 +3437,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_wasm"
-version = "0.14.2"
+version = "0.14.3"
 dependencies = [
  "console_error_panic_hook",
  "console_log",
@@ -3545,7 +3535,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.0",
 ]
 
 [[package]]
@@ -3941,7 +3931,7 @@ dependencies = [
  "getrandom 0.3.4",
  "once_cell",
  "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.61.0",
 ]
 
 [[package]]
@@ -5021,7 +5011,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.61.0",
 ]
 
 [[package]]

Cargo.toml

@@ -84,7 +84,7 @@ dashmap = { version = "6.0.1" }
 dir-test = { version = "0.4.0" }
 dunce = { version = "1.0.5" }
 drop_bomb = { version = "0.1.5" }
-etcetera = { version = "0.10.0" }
+etcetera = { version = "0.11.0" }
 fern = { version = "0.7.0" }
 filetime = { version = "0.2.23" }
 getrandom = { version = "0.3.1" }

README.md

@@ -147,8 +147,8 @@ 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/0.14.2/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.14.2/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.14.3/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.14.3/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -181,7 +181,7 @@ 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: v0.14.2
+  rev: v0.14.3
   hooks:
     # Run the linter.
     - id: ruff-check

crates/ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.14.2"
+version = "0.14.3"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }

crates/ruff_db/src/files.rs

@@ -470,6 +470,11 @@ impl File {
         self.source_type(db).is_stub()
     }
 
+    /// Returns `true` if the file is an `__init__.pyi`
+    pub fn is_package_stub(self, db: &dyn Db) -> bool {
+        self.path(db).as_str().ends_with("__init__.pyi")
+    }
+
     pub fn source_type(self, db: &dyn Db) -> PySourceType {
         match self.path(db) {
             FilePath::System(path) => path

crates/ruff_linter/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_linter"
-version = "0.14.2"
+version = "0.14.3"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }

crates/ruff_server/src/server/api/diagnostics.rs

@@ -1,7 +1,4 @@
-use lsp_types::Url;
-
 use crate::{
-    Session,
     lint::DiagnosticsMap,
     session::{Client, DocumentQuery, DocumentSnapshot},
 };
@@ -22,21 +19,10 @@ pub(super) fn generate_diagnostics(snapshot: &DocumentSnapshot) -> DiagnosticsMa
 }
 
 pub(super) fn publish_diagnostics_for_document(
-    session: &Session,
-    url: &Url,
+    snapshot: &DocumentSnapshot,
     client: &Client,
 ) -> crate::server::Result<()> {
-    // Publish diagnostics if the client doesn't support pull diagnostics
-    if session.resolved_client_capabilities().pull_diagnostics {
-        return Ok(());
-    }
-
-    let snapshot = session
-        .take_snapshot(url.clone())
-        .ok_or_else(|| anyhow::anyhow!("Unable to take snapshot for document with URL {url}"))
-        .with_failure_code(lsp_server::ErrorCode::InternalError)?;
-
-    for (uri, diagnostics) in generate_diagnostics(&snapshot) {
+    for (uri, diagnostics) in generate_diagnostics(snapshot) {
         client
             .send_notification::<lsp_types::notification::PublishDiagnostics>(
                 lsp_types::PublishDiagnosticsParams {
@@ -52,14 +38,9 @@ pub(super) fn publish_diagnostics_for_document(
 }
 
 pub(super) fn clear_diagnostics_for_document(
-    session: &Session,
     query: &DocumentQuery,
     client: &Client,
 ) -> crate::server::Result<()> {
-    if session.resolved_client_capabilities().pull_diagnostics {
-        return Ok(());
-    }
-
     client
         .send_notification::<lsp_types::notification::PublishDiagnostics>(
             lsp_types::PublishDiagnosticsParams {

crates/ruff_server/src/server/api/notifications/did_change.rs

@@ -31,7 +31,11 @@ impl super::SyncNotificationHandler for DidChange {
             .update_text_document(&key, content_changes, new_version)
             .with_failure_code(ErrorCode::InternalError)?;
 
-        publish_diagnostics_for_document(session, &key.into_url(), client)?;
+        // Publish diagnostics if the client doesn't support pull diagnostics
+        if !session.resolved_client_capabilities().pull_diagnostics {
+            let snapshot = session.take_snapshot(key.into_url()).unwrap();
+            publish_diagnostics_for_document(&snapshot, client)?;
+        }
 
         Ok(())
     }

crates/ruff_server/src/server/api/notifications/did_change_notebook.rs

@@ -27,7 +27,10 @@ impl super::SyncNotificationHandler for DidChangeNotebook {
             .with_failure_code(ErrorCode::InternalError)?;
 
         // publish new diagnostics
-        publish_diagnostics_for_document(session, &key.into_url(), client)?;
+        let snapshot = session
+            .take_snapshot(key.into_url())
+            .expect("snapshot should be available");
+        publish_diagnostics_for_document(&snapshot, client)?;
 
         Ok(())
     }

crates/ruff_server/src/server/api/notifications/did_change_watched_files.rs

@@ -31,13 +31,19 @@ impl super::SyncNotificationHandler for DidChangeWatchedFiles {
             } else {
                 // publish diagnostics for text documents
                 for url in session.text_document_urls() {
-                    publish_diagnostics_for_document(session, url, client)?;
+                    let snapshot = session
+                        .take_snapshot(url.clone())
+                        .expect("snapshot should be available");
+                    publish_diagnostics_for_document(&snapshot, client)?;
                 }
             }
 
             // always publish diagnostics for notebook files (since they don't use pull diagnostics)
             for url in session.notebook_document_urls() {
-                publish_diagnostics_for_document(session, url, client)?;
+                let snapshot = session
+                    .take_snapshot(url.clone())
+                    .expect("snapshot should be available");
+                publish_diagnostics_for_document(&snapshot, client)?;
             }
         }
 

crates/ruff_server/src/server/api/notifications/did_close.rs

@@ -27,7 +27,7 @@ impl super::SyncNotificationHandler for DidClose {
             );
             return Ok(());
         };
-        clear_diagnostics_for_document(session, snapshot.query(), client)?;
+        clear_diagnostics_for_document(snapshot.query(), client)?;
 
         session
             .close_document(&key)

crates/ruff_server/src/server/api/notifications/did_open.rs

@@ -1,5 +1,6 @@
 use crate::TextDocument;
 use crate::server::Result;
+use crate::server::api::LSPResult;
 use crate::server::api::diagnostics::publish_diagnostics_for_document;
 use crate::session::{Client, Session};
 use lsp_types as types;
@@ -29,7 +30,16 @@ impl super::SyncNotificationHandler for DidOpen {
 
         session.open_text_document(uri.clone(), document);
 
-        publish_diagnostics_for_document(session, &uri, client)?;
+        // Publish diagnostics if the client doesn't support pull diagnostics
+        if !session.resolved_client_capabilities().pull_diagnostics {
+            let snapshot = session
+                .take_snapshot(uri.clone())
+                .ok_or_else(|| {
+                    anyhow::anyhow!("Unable to take snapshot for document with URL {uri}")
+                })
+                .with_failure_code(lsp_server::ErrorCode::InternalError)?;
+            publish_diagnostics_for_document(&snapshot, client)?;
+        }
 
         Ok(())
     }

crates/ruff_server/src/server/api/notifications/did_open_notebook.rs

@@ -40,7 +40,10 @@ impl super::SyncNotificationHandler for DidOpenNotebook {
         session.open_notebook_document(uri.clone(), notebook);
 
         // publish diagnostics
-        publish_diagnostics_for_document(session, &uri, client)?;
+        let snapshot = session
+            .take_snapshot(uri)
+            .expect("snapshot should be available");
+        publish_diagnostics_for_document(&snapshot, client)?;
 
         Ok(())
     }

crates/ruff_wasm/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_wasm"
-version = "0.14.2"
+version = "0.14.3"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }

crates/ty/docs/rules.md

@@ -474,7 +474,7 @@ an atypical memory layout.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-argument-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L598" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L606" target="_blank">View source</a>
 </small>
 
 
@@ -501,7 +501,7 @@ func("foo")  # error: [invalid-argument-type]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-assignment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L638" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L646" target="_blank">View source</a>
 </small>
 
 
@@ -529,7 +529,7 @@ a: int = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-attribute-access" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1749" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1757" target="_blank">View source</a>
 </small>
 
 
@@ -563,7 +563,7 @@ C.instance_var = 3  # error: Cannot assign to instance variable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-await" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L660" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L668" target="_blank">View source</a>
 </small>
 
 
@@ -599,7 +599,7 @@ asyncio.run(main())
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L690" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L698" target="_blank">View source</a>
 </small>
 
 
@@ -623,7 +623,7 @@ class A(42): ...  # error: [invalid-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-context-manager" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L741" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L749" target="_blank">View source</a>
 </small>
 
 
@@ -650,7 +650,7 @@ with 1:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-declaration" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L762" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L770" target="_blank">View source</a>
 </small>
 
 
@@ -679,7 +679,7 @@ a: str
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-exception-caught" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L785" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L793" target="_blank">View source</a>
 </small>
 
 
@@ -723,7 +723,7 @@ except ZeroDivisionError:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-generic-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L821" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L829" target="_blank">View source</a>
 </small>
 
 
@@ -762,11 +762,15 @@ Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.17">0
 
 **What it does**
 
-Checks for subscript accesses with invalid keys.
+Checks for subscript accesses with invalid keys and `TypedDict` construction with an
+unknown key.
 
 **Why is this bad?**
 
-Using an invalid key will raise a `KeyError` at runtime.
+Subscripting with an invalid key will raise a `KeyError` at runtime.
+
+Creating a `TypedDict` with an unknown key is likely a mistake; if the `TypedDict` is
+`closed=true` it also violates the expectations of the type.
 
 **Examples**
 
@@ -779,6 +783,10 @@ class Person(TypedDict):
 
 alice = Person(name="Alice", age=30)
 alice["height"]  # KeyError: 'height'
+
+bob: Person = { "name": "Bob", "age": 30 }  # typo!
+
+carol = Person(name="Carol", age=25)  # typo!
 ```
 
 ## `invalid-legacy-type-variable`
@@ -787,7 +795,7 @@ alice["height"]  # KeyError: 'height'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-legacy-type-variable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L847" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L855" target="_blank">View source</a>
 </small>
 
 
@@ -822,7 +830,7 @@ def f(t: TypeVar("U")): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L896" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L904" target="_blank">View source</a>
 </small>
 
 
@@ -888,7 +896,7 @@ TypeError: can only inherit from a NamedTuple type and Generic
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L923" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L931" target="_blank">View source</a>
 </small>
 
 
@@ -938,7 +946,7 @@ def foo(x: int) -> int: ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-parameter-default" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1022" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1030" target="_blank">View source</a>
 </small>
 
 
@@ -998,7 +1006,7 @@ TypeError: Protocols can only inherit from other protocols, got <class 'int'>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-raise" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1042" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1050" target="_blank">View source</a>
 </small>
 
 
@@ -1047,7 +1055,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-return-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L619" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L627" target="_blank">View source</a>
 </small>
 
 
@@ -1072,7 +1080,7 @@ def func() -> int:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-super-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1085" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1093" target="_blank">View source</a>
 </small>
 
 
@@ -1130,7 +1138,7 @@ TODO #14889
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.6">0.0.1-alpha.6</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-alias-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L875" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L883" target="_blank">View source</a>
 </small>
 
 
@@ -1157,7 +1165,7 @@ NewAlias = TypeAliasType(get_name(), int)        # error: TypeAliasType name mus
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-checking-constant" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1124" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1132" target="_blank">View source</a>
 </small>
 
 
@@ -1187,7 +1195,7 @@ TYPE_CHECKING = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-form" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1148" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1156" target="_blank">View source</a>
 </small>
 
 
@@ -1217,7 +1225,7 @@ b: Annotated[int]  # `Annotated` expects at least two arguments
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1200" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1208" target="_blank">View source</a>
 </small>
 
 
@@ -1251,7 +1259,7 @@ f(10)  # Error
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1172" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1180" target="_blank">View source</a>
 </small>
 
 
@@ -1285,7 +1293,7 @@ class C:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-variable-constraints" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1228" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1236" target="_blank">View source</a>
 </small>
 
 
@@ -1320,7 +1328,7 @@ T = TypeVar('T', bound=str)  # valid bound TypeVar
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1257" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1265" target="_blank">View source</a>
 </small>
 
 
@@ -1345,7 +1353,7 @@ func()  # TypeError: func() missing 1 required positional argument: 'x'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-typed-dict-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1850" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1858" target="_blank">View source</a>
 </small>
 
 
@@ -1378,7 +1386,7 @@ alice["age"]  # KeyError
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20no-matching-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1276" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1284" target="_blank">View source</a>
 </small>
 
 
@@ -1407,7 +1415,7 @@ func("string")  # error: [no-matching-overload]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20non-subscriptable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1299" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1307" target="_blank">View source</a>
 </small>
 
 
@@ -1431,7 +1439,7 @@ Subscripting an object that does not support it will raise a `TypeError` at runt
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20not-iterable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1317" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1325" target="_blank">View source</a>
 </small>
 
 
@@ -1457,7 +1465,7 @@ for i in 34:  # TypeError: 'int' object is not iterable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20parameter-already-assigned" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1368" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1376" target="_blank">View source</a>
 </small>
 
 
@@ -1484,7 +1492,7 @@ f(1, x=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20positional-only-parameter-as-kwarg" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1603" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1611" target="_blank">View source</a>
 </small>
 
 
@@ -1542,7 +1550,7 @@ def test(): -> "int":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20static-assert-error" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1725" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1733" target="_blank">View source</a>
 </small>
 
 
@@ -1572,7 +1580,7 @@ static_assert(int(2.0 * 3.0) == 6)  # error: does not have a statically known tr
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20subclass-of-final-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1459" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1467" target="_blank">View source</a>
 </small>
 
 
@@ -1601,7 +1609,7 @@ class B(A): ...  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20too-many-positional-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1504" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1512" target="_blank">View source</a>
 </small>
 
 
@@ -1628,7 +1636,7 @@ f("foo")  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20type-assertion-failure" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1482" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1490" target="_blank">View source</a>
 </small>
 
 
@@ -1656,7 +1664,7 @@ def _(x: int):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unavailable-implicit-super-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1525" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1533" target="_blank">View source</a>
 </small>
 
 
@@ -1702,7 +1710,7 @@ class A:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1582" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1590" target="_blank">View source</a>
 </small>
 
 
@@ -1729,7 +1737,7 @@ f(x=1, y=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1624" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1632" target="_blank">View source</a>
 </small>
 
 
@@ -1757,7 +1765,7 @@ A().foo  # AttributeError: 'A' object has no attribute 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1646" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1654" target="_blank">View source</a>
 </small>
 
 
@@ -1782,7 +1790,7 @@ import foo  # ModuleNotFoundError: No module named 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1665" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1673" target="_blank">View source</a>
 </small>
 
 
@@ -1807,7 +1815,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-bool-conversion" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1337" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1345" target="_blank">View source</a>
 </small>
 
 
@@ -1844,7 +1852,7 @@ b1 < b2 < b1  # exception raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-operator" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1684" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1692" target="_blank">View source</a>
 </small>
 
 
@@ -1872,7 +1880,7 @@ A() + A()  # TypeError: unsupported operand type(s) for +: 'A' and 'A'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20zero-stepsize-in-slice" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1706" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1714" target="_blank">View source</a>
 </small>
 
 
@@ -2026,7 +2034,7 @@ a = 20 / 0  # type: ignore
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1389" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1397" target="_blank">View source</a>
 </small>
 
 
@@ -2086,7 +2094,7 @@ A()[0]  # TypeError: 'A' object is not subscriptable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1411" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1419" target="_blank">View source</a>
 </small>
 
 
@@ -2118,7 +2126,7 @@ from module import a  # ImportError: cannot import name 'a' from 'module'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20redundant-cast" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1777" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1785" target="_blank">View source</a>
 </small>
 
 
@@ -2145,7 +2153,7 @@ cast(int, f())  # Redundant
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20undefined-reveal" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1564" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1572" target="_blank">View source</a>
 </small>
 
 
@@ -2169,7 +2177,7 @@ reveal_type(1)  # NameError: name 'reveal_type' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.15">0.0.1-alpha.15</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-global" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1798" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1806" target="_blank">View source</a>
 </small>
 
 
@@ -2227,7 +2235,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.7">0.0.1-alpha.7</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L708" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L716" target="_blank">View source</a>
 </small>
 
 
@@ -2266,7 +2274,7 @@ class D(C): ...  # error: [unsupported-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20useless-overload-body" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L966" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L974" target="_blank">View source</a>
 </small>
 
 
@@ -2353,7 +2361,7 @@ Dividing by zero raises a `ZeroDivisionError` at runtime.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1437" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1445" target="_blank">View source</a>
 </small>
 
 

crates/ty_ide/src/completion.rs

@@ -212,7 +212,10 @@ pub fn completion<'db>(
     offset: TextSize,
 ) -> Vec<Completion<'db>> {
     let parsed = parsed_module(db, file).load(db);
-    if is_in_comment(&parsed, offset) || is_in_string(&parsed, offset) {
+
+    let tokens = tokens_start_before(parsed.tokens(), offset);
+
+    if is_in_comment(tokens) || is_in_string(tokens) || is_in_definition_place(db, tokens, file) {
         return vec![];
     }
 
@@ -829,8 +832,7 @@ fn find_typed_text(
 
 /// Whether the given offset within the parsed module is within
 /// a comment or not.
-fn is_in_comment(parsed: &ParsedModuleRef, offset: TextSize) -> bool {
-    let tokens = tokens_start_before(parsed.tokens(), offset);
+fn is_in_comment(tokens: &[Token]) -> bool {
     tokens.last().is_some_and(|t| t.kind().is_comment())
 }
 
@@ -839,8 +841,7 @@ fn is_in_comment(parsed: &ParsedModuleRef, offset: TextSize) -> bool {
 ///
 /// Note that this will return `false` when positioned within an
 /// interpolation block in an f-string or a t-string.
-fn is_in_string(parsed: &ParsedModuleRef, offset: TextSize) -> bool {
-    let tokens = tokens_start_before(parsed.tokens(), offset);
+fn is_in_string(tokens: &[Token]) -> bool {
     tokens.last().is_some_and(|t| {
         matches!(
             t.kind(),
@@ -849,6 +850,31 @@ fn is_in_string(parsed: &ParsedModuleRef, offset: TextSize) -> bool {
     })
 }
 
+/// If the tokens end with `class f` or `def f` we return true.
+/// If the tokens end with `class` or `def`, we return false.
+/// This is fine because we don't provide completions anyway.
+fn is_in_definition_place(db: &dyn Db, tokens: &[Token], file: File) -> bool {
+    let is_definition_keyword = |token: &Token| {
+        if matches!(
+            token.kind(),
+            TokenKind::Def | TokenKind::Class | TokenKind::Type
+        ) {
+            true
+        } else if token.kind() == TokenKind::Name {
+            let source = source_text(db, file);
+            &source[token.range()] == "type"
+        } else {
+            false
+        }
+    };
+
+    tokens
+        .len()
+        .checked_sub(2)
+        .and_then(|i| tokens.get(i))
+        .is_some_and(is_definition_keyword)
+}
+
 /// Order completions according to the following rules:
 ///
 /// 1) Names with no underscore prefix
@@ -4058,6 +4084,86 @@ def f[T](x: T):
         test.build().contains("__repr__");
     }
 
+    #[test]
+    fn no_completions_in_function_def_name() {
+        let builder = completion_test_builder(
+            "\
+def f<CURSOR>
+    ",
+        );
+
+        assert!(builder.auto_import().build().completions().is_empty());
+    }
+
+    #[test]
+    fn completions_in_function_def_empty_name() {
+        let builder = completion_test_builder(
+            "\
+def <CURSOR>
+        ",
+        );
+
+        // This is okay because the ide will not request completions when the cursor is in this position.
+        assert!(!builder.auto_import().build().completions().is_empty());
+    }
+
+    #[test]
+    fn no_completions_in_class_def_name() {
+        let builder = completion_test_builder(
+            "\
+class f<CURSOR>
+    ",
+        );
+
+        assert!(builder.auto_import().build().completions().is_empty());
+    }
+
+    #[test]
+    fn completions_in_class_def_empty_name() {
+        let builder = completion_test_builder(
+            "\
+class <CURSOR>
+        ",
+        );
+
+        // This is okay because the ide will not request completions when the cursor is in this position.
+        assert!(!builder.auto_import().build().completions().is_empty());
+    }
+
+    #[test]
+    fn no_completions_in_type_def_name() {
+        let builder = completion_test_builder(
+            "\
+type f<CURSOR> = int
+    ",
+        );
+
+        assert!(builder.auto_import().build().completions().is_empty());
+    }
+
+    #[test]
+    fn no_completions_in_maybe_type_def_name() {
+        let builder = completion_test_builder(
+            "\
+type f<CURSOR>
+       ",
+        );
+
+        assert!(builder.auto_import().build().completions().is_empty());
+    }
+
+    #[test]
+    fn completions_in_type_def_empty_name() {
+        let builder = completion_test_builder(
+            "\
+type <CURSOR>
+        ",
+        );
+
+        // This is okay because the ide will not request completions when the cursor is in this position.
+        assert!(!builder.auto_import().build().completions().is_empty());
+    }
+
     /// A way to create a simple single-file (named `main.py`) completion test
     /// builder.
     ///

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

@@ -427,14 +427,13 @@ a = f("a")
 reveal_type(a)  # revealed: list[Literal["a"]]
 
 b: list[int | Literal["a"]] = f("a")
-reveal_type(b)  # revealed: list[Literal["a"] | int]
+reveal_type(b)  # revealed: list[int | Literal["a"]]
 
 c: list[int | str] = f("a")
-reveal_type(c)  # revealed: list[str | int]
+reveal_type(c)  # revealed: list[int | str]
 
 d: list[int | tuple[int, int]] = f((1, 2))
-# TODO: We could avoid reordering the union elements here.
-reveal_type(d)  # revealed: list[tuple[int, int] | int]
+reveal_type(d)  # revealed: list[int | tuple[int, int]]
 
 e: list[int] = f(True)
 reveal_type(e)  # revealed: list[int]
@@ -455,7 +454,54 @@ j: int | str = f2(True)
 reveal_type(j)  # revealed: Literal[True]
 ```
 
-Types are not widened unnecessarily:
+## Prefer the declared type of generic classes
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from typing import Any
+
+def f[T](x: T) -> list[T]:
+    return [x]
+
+def f2[T](x: T) -> list[T] | None:
+    return [x]
+
+def f3[T](x: T) -> list[T] | dict[T, T]:
+    return [x]
+
+a = f(1)
+reveal_type(a)  # revealed: list[Literal[1]]
+
+b: list[Any] = f(1)
+reveal_type(b)  # revealed: list[Any]
+
+c: list[Any] = [1]
+reveal_type(c)  # revealed: list[Any]
+
+d: list[Any] | None = f(1)
+reveal_type(d)  # revealed: list[Any]
+
+e: list[Any] | None = [1]
+reveal_type(e)  # revealed: list[Any]
+
+f: list[Any] | None = f2(1)
+reveal_type(f)  # revealed: list[Any] | None
+
+g: list[Any] | dict[Any, Any] = f3(1)
+# TODO: Better constraint solver.
+reveal_type(g)  # revealed: list[Literal[1]] | dict[Literal[1], Literal[1]]
+```
+
+## Prefer the inferred type of non-generic classes
+
+```toml
+[environment]
+python-version = "3.12"
+```
 
 ```py
 def id[T](x: T) -> T:

crates/ty_python_semantic/resources/mdtest/bidirectional.md

@@ -50,8 +50,6 @@ def _(l: list[int] | None = None):
 def f[T](x: T, cond: bool) -> T | list[T]:
     return x if cond else [x]
 
-# TODO: no error
-# error: [invalid-assignment] "Object of type `Literal[1] | list[Literal[1]]` is not assignable to `int | list[int]`"
 l5: int | list[int] = f(1, True)
 ```
 

crates/ty_python_semantic/resources/mdtest/dataclasses/dataclasses.md

@@ -838,6 +838,40 @@ class WrappedIntAndExtraData[T](Wrap[int]):
 reveal_type(WrappedIntAndExtraData[bytes].__init__)
 ```
 
+### Non-dataclass inheriting from generic dataclass
+
+This is a regression test for <https://github.com/astral-sh/ty/issues/1427>.
+
+When a non-dataclass inherits from a generic dataclass, the generic type parameters should still be
+properly inferred when calling the inherited `__init__` method.
+
+```py
+from dataclasses import dataclass
+
+@dataclass
+class ParentDataclass[T]:
+    value: T
+
+# Non-dataclass inheriting from generic dataclass
+class ChildOfParentDataclass[T](ParentDataclass[T]): ...
+
+def uses_dataclass[T](x: T) -> ChildOfParentDataclass[T]:
+    return ChildOfParentDataclass(x)
+
+# TODO: ParentDataclass.__init__ should show generic types, not Unknown
+# revealed: (self: ParentDataclass[Unknown], value: Unknown) -> None
+reveal_type(ParentDataclass.__init__)
+
+# revealed: (self: ParentDataclass[T@ChildOfParentDataclass], value: T@ChildOfParentDataclass) -> None
+reveal_type(ChildOfParentDataclass.__init__)
+
+result_int = uses_dataclass(42)
+reveal_type(result_int)  # revealed: ChildOfParentDataclass[Literal[42]]
+
+result_str = uses_dataclass("hello")
+reveal_type(result_str)  # revealed: ChildOfParentDataclass[Literal["hello"]]
+```
+
 ## Descriptor-typed fields
 
 ### Same type in `__get__` and `__set__`

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

@@ -545,3 +545,28 @@ def f(x: T, y: Not[T]) -> T:
     y = x  # error: [invalid-assignment]
     return x
 ```
+
+## Prefer exact matches for constrained typevars
+
+```py
+from typing import TypeVar
+
+class Base: ...
+class Sub(Base): ...
+
+# We solve to `Sub`, regardless of the order of constraints.
+T = TypeVar("T", Base, Sub)
+T2 = TypeVar("T2", Sub, Base)
+
+def f(x: T) -> list[T]:
+    return [x]
+
+def f2(x: T2) -> list[T2]:
+    return [x]
+
+x: list[Sub] = f(Sub())
+reveal_type(x)  # revealed: list[Sub]
+
+y: list[Sub] = f2(Sub())
+reveal_type(y)  # revealed: list[Sub]
+```

crates/ty_python_semantic/resources/mdtest/import/nonstandard_conventions.md

@@ -0,0 +1,824 @@
+# Nonstandard Import Conventions
+
+This document covers ty-specific extensions to the
+[standard import conventions](https://typing.python.org/en/latest/spec/distributing.html#import-conventions).
+
+It's a common idiom for a package's `__init__.py(i)` to include several imports like
+`from . import mysubmodule`, with the intent that the `mypackage.mysubmodule` attribute should work
+for anyone who only imports `mypackage`.
+
+In the context of a `.py` we handle this well through our general attempts to faithfully implement
+import side-effects. However for `.pyi` files we are expected to apply
+[a more strict set of rules](https://typing.python.org/en/latest/spec/distributing.html#import-conventions)
+to encourage intentional API design. Although `.pyi` files are explicitly designed to work with
+typecheckers, which ostensibly should all enforce these strict rules, every typechecker has its own
+defacto "extensions" to them and so a few idioms like `from . import mysubmodule` have found their
+way into `.pyi` files too.
+
+Thus for the sake of compatibility, we need to define our own "extensions". Any extensions we define
+here have several competing concerns:
+
+- Extensions should ideally be kept narrow to continue to encourage explicit API design
+- Extensions should be easy to explain, document, and understand
+- Extensions should ideally still be a subset of runtime behaviour (if it works in a stub, it works
+    at runtime)
+- Extensions should ideally not make `.pyi` files more permissive than `.py` files (if it works in a
+    stub, it works in an impl)
+
+To that end we define the following extension:
+
+> If an `__init__.pyi` for `mypackage` contains a `from...import` targetting a direct submodule of
+> `mypackage`, then that submodule should be available as an attribute of `mypackage`.
+
+## Relative `from` Import of Direct Submodule in `__init__`
+
+The `from . import submodule` idiom in an `__init__.pyi` is fairly explicit and we should definitely
+support it.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from . import imported
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`mypackage/fails.pyi`:
+
+```pyi
+Y: int = 47
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+reveal_type(mypackage.imported.X)  # revealed: int
+# error: "has no member `fails`"
+reveal_type(mypackage.fails.Y)  # revealed: Unknown
+```
+
+## Relative `from` Import of Direct Submodule in `__init__` (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from . import imported
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`mypackage/fails.py`:
+
+```py
+Y: int = 47
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+reveal_type(mypackage.imported.X)  # revealed: int
+# error: "has no member `fails`"
+reveal_type(mypackage.fails.Y)  # revealed: Unknown
+```
+
+## Absolute `from` Import of Direct Submodule in `__init__`
+
+If an absolute `from...import` happens to import a submodule, it works just as well as a relative
+one.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from mypackage import imported
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`mypackage/fails.pyi`:
+
+```pyi
+Y: int = 47
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+reveal_type(mypackage.imported.X)  # revealed: int
+# error: "has no member `fails`"
+reveal_type(mypackage.fails.Y)  # revealed: Unknown
+```
+
+## Absolute `from` Import of Direct Submodule in `__init__` (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from mypackage import imported
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`mypackage/fails.py`:
+
+```py
+Y: int = 47
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+reveal_type(mypackage.imported.X)  # revealed: int
+# error: "has no member `fails`"
+reveal_type(mypackage.fails.Y)  # revealed: Unknown
+```
+
+## Import of Direct Submodule in `__init__`
+
+An `import` that happens to import a submodule does not expose the submodule as an attribute. (This
+is an arbitrary decision and can be changed easily!)
+
+`mypackage/__init__.pyi`:
+
+```pyi
+import mypackage.imported
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this is probably safe to allow, as it's an unambiguous import of a submodule
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+```
+
+## Import of Direct Submodule in `__init__` (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+import mypackage.imported
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this is probably safe to allow, as it's an unambiguous import of a submodule
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+```
+
+## Relative `from` Import of Nested Submodule in `__init__`
+
+`from .submodule import nested` in an `__init__.pyi` is currently not supported as a way to expose
+`mypackage.submodule` or `mypackage.submodule.nested` but it could be.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from .submodule import nested
+```
+
+`mypackage/submodule/__init__.pyi`:
+
+```pyi
+```
+
+`mypackage/submodule/nested.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to allow
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+```
+
+## Relative `from` Import of Nested Submodule in `__init__` (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from .submodule import nested
+```
+
+`mypackage/submodule/__init__.py`:
+
+```py
+```
+
+`mypackage/submodule/nested.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to support
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+```
+
+## Absolute `from` Import of Nested Submodule in `__init__`
+
+`from mypackage.submodule import nested` in an `__init__.pyi` is currently not supported as a way to
+expose `mypackage.submodule` or `mypackage.submodule.nested` but it could be.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from mypackage.submodule import nested
+```
+
+`mypackage/submodule/__init__.pyi`:
+
+```pyi
+```
+
+`mypackage/submodule/nested.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to support
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+```
+
+## Absolute `from` Import of Nested Submodule in `__init__` (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from mypackage.submodule import nested
+```
+
+`mypackage/submodule/__init__.py`:
+
+```py
+```
+
+`mypackage/submodule/nested.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to support
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+```
+
+## Import of Nested Submodule in `__init__`
+
+`import mypackage.submodule.nested` in an `__init__.pyi` is currently not supported as a way to
+expose `mypackage.submodule` or `mypackage.submodule.nested` but it could be.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+import mypackage.submodule.nested
+```
+
+`mypackage/submodule/__init__.pyi`:
+
+```pyi
+```
+
+`mypackage/submodule/nested.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to support, and is probably safe to do as it's unambiguous
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+```
+
+## Import of Nested Submodule in `__init__` (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+import mypackage.submodule.nested
+```
+
+`mypackage/submodule/__init__.py`:
+
+```py
+```
+
+`mypackage/submodule/nested.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to support, and is probably safe to do as it's unambiguous
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested)  # revealed: Unknown
+# error: "has no member `submodule`"
+reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+```
+
+## Relative `from` Import of Direct Submodule in `__init__`, Mismatched Alias
+
+Renaming the submodule to something else disables the `__init__.pyi` idiom.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from . import imported as imported_m
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+# error: "has no member `imported_m`"
+reveal_type(mypackage.imported_m.X)  # revealed: Unknown
+```
+
+## Relative `from` Import of Direct Submodule in `__init__`, Mismatched Alias (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from . import imported as imported_m
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to support, as it works at runtime
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+reveal_type(mypackage.imported_m.X)  # revealed: int
+```
+
+## Relative `from` Import of Direct Submodule in `__init__`, Matched Alias
+
+The `__init__.pyi` idiom should definitely always work if the submodule is renamed to itself, as
+this is the re-export idiom.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from . import imported as imported
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+reveal_type(mypackage.imported.X)  # revealed: int
+```
+
+## Relative `from` Import of Direct Submodule in `__init__`, Matched Alias (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from . import imported as imported
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+reveal_type(mypackage.imported.X)  # revealed: int
+```
+
+## Star Import Unaffected
+
+Even if the `__init__` idiom is in effect, star imports do not pick it up. (This is an arbitrary
+decision that mostly fell out of the implementation details and can be changed!)
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from . import imported
+Z: int = 17
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+from mypackage import *
+
+# TODO: this would be nice to support (available_submodule_attributes isn't visible to `*` imports)
+# error: "`imported` used when not defined"
+reveal_type(imported.X)  # revealed: Unknown
+reveal_type(Z)  # revealed: int
+```
+
+## Star Import Unaffected (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from . import imported
+
+Z: int = 17
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+from mypackage import *
+
+reveal_type(imported.X)  # revealed: int
+reveal_type(Z)  # revealed: int
+```
+
+## `from` Import of Non-Submodule
+
+A from import that terminates in a non-submodule should not expose the intermediate submodules as
+attributes. This is an arbitrary decision but on balance probably safe and correct, as otherwise it
+would be hard for a stub author to be intentional about the submodules being exposed as attributes.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from .imported import X
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+```
+
+## `from` Import of Non-Submodule (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from .imported import X
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+
+# TODO: this would be nice to support, as it works at runtime
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+```
+
+## `from` Import of Other Package's Submodule
+
+`from mypackage import submodule` from outside the package is not modeled as a side-effect on
+`mypackage`, even in the importing file (this could be changed!).
+
+`mypackage/__init__.pyi`:
+
+```pyi
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+from mypackage import imported
+
+# TODO: this would be nice to support, but it's dangerous with available_submodule_attributes
+reveal_type(imported.X)  # revealed: int
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+```
+
+## `from` Import of Other Package's Submodule (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+```
+
+`mypackage/imported.py`:
+
+```py
+X: int = 42
+```
+
+`main.py`:
+
+```py
+import mypackage
+from mypackage import imported
+
+# TODO: this would be nice to support, as it works at runtime
+reveal_type(imported.X)  # revealed: int
+# error: "has no member `imported`"
+reveal_type(mypackage.imported.X)  # revealed: Unknown
+```
+
+## `from` Import of Sibling Module
+
+`from . import submodule` from a sibling module is not modeled as a side-effect on `mypackage` or a
+re-export from `submodule`.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+```
+
+`mypackage/imported.pyi`:
+
+```pyi
+from . import fails
+X: int = 42
+```
+
+`mypackage/fails.pyi`:
+
+```pyi
+Y: int = 47
+```
+
+`main.py`:
+
+```py
+import mypackage
+from mypackage import imported
+
+reveal_type(imported.X)  # revealed: int
+# error: "has no member `fails`"
+reveal_type(imported.fails.Y)  # revealed: Unknown
+# error: "has no member `fails`"
+reveal_type(mypackage.fails.Y)  # revealed: Unknown
+```
+
+## `from` Import of Sibling Module (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+```
+
+`mypackage/imported.py`:
+
+```py
+from . import fails
+
+X: int = 42
+```
+
+`mypackage/fails.py`:
+
+```py
+Y: int = 47
+```
+
+`main.py`:
+
+```py
+import mypackage
+from mypackage import imported
+
+reveal_type(imported.X)  # revealed: int
+reveal_type(imported.fails.Y)  # revealed: int
+# error: "has no member `fails`"
+reveal_type(mypackage.fails.Y)  # revealed: Unknown
+```
+
+## Fractal Re-export Nameclash Problems
+
+This precise configuration of:
+
+- a subpackage that defines a submodule with its own name
+- that in turn defines a function/class with its own name
+- and re-exporting that name through every layer using `from` imports and `__all__`
+
+Can easily result in the typechecker getting "confused" and thinking imports of the name from the
+top-level package are referring to the subpackage and not the function/class. This issue can be
+found with the `lobpcg` function in `scipy.sparse.linalg`.
+
+This kind of failure mode is why the rule is restricted to *direct* submodule imports, as anything
+more powerful than that in the current implementation strategy quickly gets the functions and
+submodules mixed up.
+
+`mypackage/__init__.pyi`:
+
+```pyi
+from .funcmod import funcmod
+
+__all__ = ["funcmod"]
+```
+
+`mypackage/funcmod/__init__.pyi`:
+
+```pyi
+from .funcmod import funcmod
+
+__all__ = ["funcmod"]
+```
+
+`mypackage/funcmod/funcmod.pyi`:
+
+```pyi
+__all__ = ["funcmod"]
+
+def funcmod(x: int) -> int: ...
+```
+
+`main.py`:
+
+```py
+from mypackage import funcmod
+
+x = funcmod(1)
+```
+
+## Fractal Re-export Nameclash Problems (Non-Stub Check)
+
+`mypackage/__init__.py`:
+
+```py
+from .funcmod import funcmod
+
+__all__ = ["funcmod"]
+```
+
+`mypackage/funcmod/__init__.py`:
+
+```py
+from .funcmod import funcmod
+
+__all__ = ["funcmod"]
+```
+
+`mypackage/funcmod/funcmod.py`:
+
+```py
+__all__ = ["funcmod"]
+
+def funcmod(x: int) -> int:
+    return x
+```
+
+`main.py`:
+
+```py
+from mypackage import funcmod
+
+x = funcmod(1)
+```

crates/ty_python_semantic/resources/mdtest/snapshots/typed_dict.md_-_`TypedDict`_-_Diagnostics_(e5289abf5c570c29).snap

@@ -37,20 +37,24 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/typed_dict.md
 23 | 
 24 | def write_to_non_literal_string_key(person: Person, str_key: str):
 25 |     person[str_key] = "Alice"  # error: [invalid-key]
-26 | from typing_extensions import ReadOnly
-27 | 
-28 | class Employee(TypedDict):
-29 |     id: ReadOnly[int]
-30 |     name: str
+26 | 
+27 | def create_with_invalid_string_key():
+28 |     alice: Person = {"name": "Alice", "age": 30, "unknown": "Foo"}  # error: [invalid-key]
+29 |     bob = Person(name="Bob", age=25, unknown="Bar")  # error: [invalid-key]
+30 | from typing_extensions import ReadOnly
 31 | 
-32 | def write_to_readonly_key(employee: Employee):
-33 |     employee["id"] = 42  # error: [invalid-assignment]
+32 | class Employee(TypedDict):
+33 |     id: ReadOnly[int]
+34 |     name: str
+35 | 
+36 | def write_to_readonly_key(employee: Employee):
+37 |     employee["id"] = 42  # error: [invalid-assignment]
 ```
 
 # Diagnostics
 
 ```
-error[invalid-key]: Invalid key access on TypedDict `Person`
+error[invalid-key]: Invalid key for TypedDict `Person`
   --> src/mdtest_snippet.py:8:5
    |
  7 | def access_invalid_literal_string_key(person: Person):
@@ -66,7 +70,7 @@ info: rule `invalid-key` is enabled by default
 ```
 
 ```
-error[invalid-key]: Invalid key access on TypedDict `Person`
+error[invalid-key]: Invalid key for TypedDict `Person`
   --> src/mdtest_snippet.py:13:5
    |
 12 | def access_invalid_key(person: Person):
@@ -82,7 +86,7 @@ info: rule `invalid-key` is enabled by default
 ```
 
 ```
-error[invalid-key]: TypedDict `Person` cannot be indexed with a key of type `str`
+error[invalid-key]: Invalid key for TypedDict `Person` of type `str`
   --> src/mdtest_snippet.py:16:12
    |
 15 | def access_with_str_key(person: Person, str_key: str):
@@ -123,7 +127,7 @@ info: rule `invalid-assignment` is enabled by default
 ```
 
 ```
-error[invalid-key]: Invalid key access on TypedDict `Person`
+error[invalid-key]: Invalid key for TypedDict `Person`
   --> src/mdtest_snippet.py:22:5
    |
 21 | def write_to_non_existing_key(person: Person):
@@ -145,7 +149,39 @@ error[invalid-key]: Cannot access `Person` with a key of type `str`. Only string
 24 | def write_to_non_literal_string_key(person: Person, str_key: str):
 25 |     person[str_key] = "Alice"  # error: [invalid-key]
    |            ^^^^^^^
-26 | from typing_extensions import ReadOnly
+26 |
+27 | def create_with_invalid_string_key():
+   |
+info: rule `invalid-key` is enabled by default
+
+```
+
+```
+error[invalid-key]: Invalid key for TypedDict `Person`
+  --> src/mdtest_snippet.py:28:21
+   |
+27 | def create_with_invalid_string_key():
+28 |     alice: Person = {"name": "Alice", "age": 30, "unknown": "Foo"}  # error: [invalid-key]
+   |                     -----------------------------^^^^^^^^^--------
+   |                     |                            |
+   |                     |                            Unknown key "unknown"
+   |                     TypedDict `Person`
+29 |     bob = Person(name="Bob", age=25, unknown="Bar")  # error: [invalid-key]
+30 | from typing_extensions import ReadOnly
+   |
+info: rule `invalid-key` is enabled by default
+
+```
+
+```
+error[invalid-key]: Invalid key for TypedDict `Person`
+  --> src/mdtest_snippet.py:29:11
+   |
+27 | def create_with_invalid_string_key():
+28 |     alice: Person = {"name": "Alice", "age": 30, "unknown": "Foo"}  # error: [invalid-key]
+29 |     bob = Person(name="Bob", age=25, unknown="Bar")  # error: [invalid-key]
+   |           ------ TypedDict `Person`  ^^^^^^^^^^^^^ Unknown key "unknown"
+30 | from typing_extensions import ReadOnly
    |
 info: rule `invalid-key` is enabled by default
 
@@ -153,21 +189,21 @@ info: rule `invalid-key` is enabled by default
 
 ```
 error[invalid-assignment]: Cannot assign to key "id" on TypedDict `Employee`
-  --> src/mdtest_snippet.py:33:5
+  --> src/mdtest_snippet.py:37:5
    |
-32 | def write_to_readonly_key(employee: Employee):
-33 |     employee["id"] = 42  # error: [invalid-assignment]
+36 | def write_to_readonly_key(employee: Employee):
+37 |     employee["id"] = 42  # error: [invalid-assignment]
    |     -------- ^^^^ key is marked read-only
    |     |
    |     TypedDict `Employee`
    |
 info: Item declaration
-  --> src/mdtest_snippet.py:29:5
+  --> src/mdtest_snippet.py:33:5
    |
-28 | class Employee(TypedDict):
-29 |     id: ReadOnly[int]
+32 | class Employee(TypedDict):
+33 |     id: ReadOnly[int]
    |     ----------------- Read-only item declared here
-30 |     name: str
+34 |     name: str
    |
 info: rule `invalid-assignment` is enabled by default
 

crates/ty_python_semantic/resources/mdtest/type_properties/is_disjoint_from.md

@@ -87,6 +87,31 @@ static_assert(is_disjoint_from(memoryview, Foo))
 static_assert(is_disjoint_from(type[memoryview], type[Foo]))
 ```
 
+## Specialized `@final` types
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from typing import final
+from ty_extensions import static_assert, is_disjoint_from
+
+@final
+class Foo[T]:
+    def get(self) -> T:
+        raise NotImplementedError
+
+class A: ...
+class B: ...
+
+static_assert(not is_disjoint_from(Foo[A], Foo[B]))
+
+# TODO: `int` and `str` are disjoint bases, so these should be disjoint.
+static_assert(not is_disjoint_from(Foo[int], Foo[str]))
+```
+
 ## "Disjoint base" builtin types
 
 Most other builtins can be subclassed and can even be used in multiple inheritance. However, builtin

crates/ty_python_semantic/resources/mdtest/type_properties/satisfied_by_all_typevars.md

@@ -0,0 +1,220 @@
+# Constraint set satisfaction
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+Constraint sets exist to help us check assignability and subtyping of types in the presence of
+typevars. We construct a constraint set describing the conditions under which assignability holds
+between the two types. Then we check whether that constraint set is satisfied for the valid
+specializations of the relevant typevars. This file tests that final step.
+
+## Inferable vs non-inferable typevars
+
+Typevars can appear in _inferable_ or _non-inferable_ positions.
+
+When a typevar is in an inferable position, the constraint set only needs to be satisfied for _some_
+valid specialization. The most common inferable position occurs when invoking a generic function:
+all of the function's typevars are inferable, because we want to use the argument types to infer
+which specialization is being invoked.
+
+When a typevar is in a non-inferable position, the constraint set must be satisfied for _every_
+valid specialization. The most common non-inferable position occurs in the body of a generic
+function or class: here we don't know in advance what type the typevar will be specialized to, and
+so we have to ensure that the body is valid for all possible specializations.
+
+```py
+def f[T](t: T) -> T:
+    # In the function body, T is non-inferable. All assignability checks involving T must be
+    # satisfied for _all_ valid specializations of T.
+    return t
+
+# When invoking the function, T is inferable — we attempt to infer a specialization that is valid
+# for the particular arguments that are passed to the function. Assignability checks (in particular,
+# that the argument type is assignable to the parameter type) only need to succeed for _at least
+# one_ specialization.
+f(1)
+```
+
+In all of the examples below, for ease of reproducibility, we explicitly list the typevars that are
+inferable in each `satisfied_by_all_typevars` call; any typevar not listed is assumed to be
+non-inferable.
+
+## Unbounded typevar
+
+If a typevar has no bound or constraints, then it can specialize to any type. In an inferable
+position, that means we just need a single type (any type at all!) that satisfies the constraint
+set. In a non-inferable position, that means the constraint set must be satisfied for every possible
+type.
+
+```py
+from typing import final, Never
+from ty_extensions import ConstraintSet, static_assert
+
+class Super: ...
+class Base(Super): ...
+class Sub(Base): ...
+
+@final
+class Unrelated: ...
+
+def unbounded[T]():
+    static_assert(ConstraintSet.always().satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(ConstraintSet.always().satisfied_by_all_typevars())
+
+    static_assert(not ConstraintSet.never().satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(not ConstraintSet.never().satisfied_by_all_typevars())
+
+    # (T = Never) is a valid specialization, which satisfies (T ≤ Unrelated).
+    static_assert(ConstraintSet.range(Never, T, Unrelated).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Base) is a valid specialization, which does not satisfy (T ≤ Unrelated).
+    static_assert(not ConstraintSet.range(Never, T, Unrelated).satisfied_by_all_typevars())
+
+    # (T = Base) is a valid specialization, which satisfies (T ≤ Super).
+    static_assert(ConstraintSet.range(Never, T, Super).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Unrelated) is a valid specialization, which does not satisfy (T ≤ Super).
+    static_assert(not ConstraintSet.range(Never, T, Super).satisfied_by_all_typevars())
+
+    # (T = Base) is a valid specialization, which satisfies (T ≤ Base).
+    static_assert(ConstraintSet.range(Never, T, Base).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Unrelated) is a valid specialization, which does not satisfy (T ≤ Base).
+    static_assert(not ConstraintSet.range(Never, T, Base).satisfied_by_all_typevars())
+
+    # (T = Sub) is a valid specialization, which satisfies (T ≤ Sub).
+    static_assert(ConstraintSet.range(Never, T, Sub).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Unrelated) is a valid specialization, which does not satisfy (T ≤ Sub).
+    static_assert(not ConstraintSet.range(Never, T, Sub).satisfied_by_all_typevars())
+```
+
+## Typevar with an upper bound
+
+If a typevar has an upper bound, then it must specialize to a type that is a subtype of that bound.
+For an inferable typevar, that means we need a single type that satisfies both the constraint set
+and the upper bound. For a non-inferable typevar, that means the constraint set must be satisfied
+for every type that satisfies the upper bound.
+
+```py
+from typing import final, Never
+from ty_extensions import ConstraintSet, static_assert
+
+class Super: ...
+class Base(Super): ...
+class Sub(Base): ...
+
+@final
+class Unrelated: ...
+
+def bounded[T: Base]():
+    static_assert(ConstraintSet.always().satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(ConstraintSet.always().satisfied_by_all_typevars())
+
+    static_assert(not ConstraintSet.never().satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(not ConstraintSet.never().satisfied_by_all_typevars())
+
+    # (T = Base) is a valid specialization, which satisfies (T ≤ Super).
+    static_assert(ConstraintSet.range(Never, T, Super).satisfied_by_all_typevars(inferable=tuple[T]))
+    # Every valid specialization satisfies (T ≤ Base). Since (Base ≤ Super), every valid
+    # specialization also satisfies (T ≤ Super).
+    static_assert(ConstraintSet.range(Never, T, Super).satisfied_by_all_typevars())
+
+    # (T = Base) is a valid specialization, which satisfies (T ≤ Base).
+    static_assert(ConstraintSet.range(Never, T, Base).satisfied_by_all_typevars(inferable=tuple[T]))
+    # Every valid specialization satisfies (T ≤ Base).
+    static_assert(ConstraintSet.range(Never, T, Base).satisfied_by_all_typevars())
+
+    # (T = Sub) is a valid specialization, which satisfies (T ≤ Sub).
+    static_assert(ConstraintSet.range(Never, T, Sub).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Base) is a valid specialization, which does not satisfy (T ≤ Sub).
+    static_assert(not ConstraintSet.range(Never, T, Sub).satisfied_by_all_typevars())
+
+    # (T = Never) is a valid specialization, which satisfies (T ≤ Unrelated).
+    constraints = ConstraintSet.range(Never, T, Unrelated)
+    static_assert(constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Base) is a valid specialization, which does not satisfy (T ≤ Unrelated).
+    static_assert(not constraints.satisfied_by_all_typevars())
+
+    # Never is the only type that satisfies both (T ≤ Base) and (T ≤ Unrelated). So there is no
+    # valid specialization that satisfies (T ≤ Unrelated ∧ T ≠ Never).
+    constraints = constraints & ~ConstraintSet.range(Never, T, Never)
+    static_assert(not constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(not constraints.satisfied_by_all_typevars())
+```
+
+## Constrained typevar
+
+If a typevar has constraints, then it must specialize to one of those specific types. (Not to a
+subtype of one of those types!) For an inferable typevar, that means we need the constraint set to
+be satisfied by any one of the constraints. For a non-inferable typevar, that means we need the
+constraint set to be satisfied by all of those constraints.
+
+```py
+from typing import final, Never
+from ty_extensions import ConstraintSet, static_assert
+
+class Super: ...
+class Base(Super): ...
+class Sub(Base): ...
+
+@final
+class Unrelated: ...
+
+def constrained[T: (Base, Unrelated)]():
+    static_assert(ConstraintSet.always().satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(ConstraintSet.always().satisfied_by_all_typevars())
+
+    static_assert(not ConstraintSet.never().satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(not ConstraintSet.never().satisfied_by_all_typevars())
+
+    # (T = Unrelated) is a valid specialization, which satisfies (T ≤ Unrelated).
+    static_assert(ConstraintSet.range(Never, T, Unrelated).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Base) is a valid specialization, which does not satisfy (T ≤ Unrelated).
+    static_assert(not ConstraintSet.range(Never, T, Unrelated).satisfied_by_all_typevars())
+
+    # (T = Base) is a valid specialization, which satisfies (T ≤ Super).
+    static_assert(ConstraintSet.range(Never, T, Super).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Unrelated) is a valid specialization, which does not satisfy (T ≤ Super).
+    static_assert(not ConstraintSet.range(Never, T, Super).satisfied_by_all_typevars())
+
+    # (T = Base) is a valid specialization, which satisfies (T ≤ Base).
+    static_assert(ConstraintSet.range(Never, T, Base).satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Unrelated) is a valid specialization, which does not satisfy (T ≤ Base).
+    static_assert(not ConstraintSet.range(Never, T, Base).satisfied_by_all_typevars())
+
+    # Neither (T = Base) nor (T = Unrelated) satisfy (T ≤ Sub).
+    static_assert(not ConstraintSet.range(Never, T, Sub).satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(not ConstraintSet.range(Never, T, Sub).satisfied_by_all_typevars())
+
+    # (T = Base) and (T = Unrelated) both satisfy (T ≤ Super ∨ T ≤ Unrelated).
+    constraints = ConstraintSet.range(Never, T, Super) | ConstraintSet.range(Never, T, Unrelated)
+    static_assert(constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(constraints.satisfied_by_all_typevars())
+
+    # (T = Base) and (T = Unrelated) both satisfy (T ≤ Base ∨ T ≤ Unrelated).
+    constraints = ConstraintSet.range(Never, T, Base) | ConstraintSet.range(Never, T, Unrelated)
+    static_assert(constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(constraints.satisfied_by_all_typevars())
+
+    # (T = Unrelated) is a valid specialization, which satisfies (T ≤ Sub ∨ T ≤ Unrelated).
+    constraints = ConstraintSet.range(Never, T, Sub) | ConstraintSet.range(Never, T, Unrelated)
+    static_assert(constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Base) is a valid specialization, which does not satisfy (T ≤ Sub ∨ T ≤ Unrelated).
+    static_assert(not constraints.satisfied_by_all_typevars())
+
+    # (T = Unrelated) is a valid specialization, which satisfies (T = Super ∨ T = Unrelated).
+    constraints = ConstraintSet.range(Super, T, Super) | ConstraintSet.range(Unrelated, T, Unrelated)
+    static_assert(constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Base) is a valid specialization, which does not satisfy (T = Super ∨ T = Unrelated).
+    static_assert(not constraints.satisfied_by_all_typevars())
+
+    # (T = Base) and (T = Unrelated) both satisfy (T = Base ∨ T = Unrelated).
+    constraints = ConstraintSet.range(Base, T, Base) | ConstraintSet.range(Unrelated, T, Unrelated)
+    static_assert(constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    static_assert(constraints.satisfied_by_all_typevars())
+
+    # (T = Unrelated) is a valid specialization, which satisfies (T = Sub ∨ T = Unrelated).
+    constraints = ConstraintSet.range(Sub, T, Sub) | ConstraintSet.range(Unrelated, T, Unrelated)
+    static_assert(constraints.satisfied_by_all_typevars(inferable=tuple[T]))
+    # (T = Base) is a valid specialization, which does not satisfy (T = Sub ∨ T = Unrelated).
+    static_assert(not constraints.satisfied_by_all_typevars())
+```

crates/ty_python_semantic/resources/mdtest/typed_dict.md

@@ -29,7 +29,7 @@ alice: Person = {"name": "Alice", "age": 30}
 reveal_type(alice["name"])  # revealed: str
 reveal_type(alice["age"])  # revealed: int | None
 
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "non_existing""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "non_existing""
 reveal_type(alice["non_existing"])  # revealed: Unknown
 ```
 
@@ -41,7 +41,7 @@ bob = Person(name="Bob", age=25)
 reveal_type(bob["name"])  # revealed: str
 reveal_type(bob["age"])  # revealed: int | None
 
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "non_existing""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "non_existing""
 reveal_type(bob["non_existing"])  # revealed: Unknown
 ```
 
@@ -69,7 +69,7 @@ def name_or_age() -> Literal["name", "age"]:
 carol: Person = {NAME: "Carol", AGE: 20}
 
 reveal_type(carol[NAME])  # revealed: str
-# error: [invalid-key] "TypedDict `Person` cannot be indexed with a key of type `str`"
+# error: [invalid-key] "Invalid key for TypedDict `Person` of type `str`"
 reveal_type(carol[non_literal()])  # revealed: Unknown
 reveal_type(carol[name_or_age()])  # revealed: str | int | None
 
@@ -81,7 +81,7 @@ def _():
 
 CAPITALIZED_NAME = "Name"
 
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "Name" - did you mean "name"?"
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "Name" - did you mean "name"?"
 # error: [missing-typed-dict-key] "Missing required key 'name' in TypedDict `Person` constructor"
 dave: Person = {CAPITALIZED_NAME: "Dave", "age": 20}
 
@@ -104,9 +104,9 @@ eve2a: Person = {"age": 22}
 # error: [missing-typed-dict-key] "Missing required key 'name' in TypedDict `Person` constructor"
 eve2b = Person(age=22)
 
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 eve3a: Person = {"name": "Eve", "age": 25, "extra": True}
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 eve3b = Person(name="Eve", age=25, extra=True)
 ```
 
@@ -157,10 +157,10 @@ bob["name"] = None
 Assignments to non-existing keys are disallowed:
 
 ```py
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 alice["extra"] = True
 
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 bob["extra"] = True
 ```
 
@@ -185,10 +185,10 @@ alice: Person = {"inner": {"name": "Alice", "age": 30}}
 reveal_type(alice["inner"]["name"])  # revealed: str
 reveal_type(alice["inner"]["age"])  # revealed: int | None
 
-# error: [invalid-key] "Invalid key access on TypedDict `Inner`: Unknown key "non_existing""
+# error: [invalid-key] "Invalid key for TypedDict `Inner`: Unknown key "non_existing""
 reveal_type(alice["inner"]["non_existing"])  # revealed: Unknown
 
-# error: [invalid-key] "Invalid key access on TypedDict `Inner`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Inner`: Unknown key "extra""
 alice: Person = {"inner": {"name": "Alice", "age": 30, "extra": 1}}
 ```
 
@@ -267,22 +267,22 @@ a_person = {"name": None, "age": 30}
 All of these have an extra field that is not defined in the `TypedDict`:
 
 ```py
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 alice4: Person = {"name": "Alice", "age": 30, "extra": True}
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 Person(name="Alice", age=30, extra=True)
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 Person({"name": "Alice", "age": 30, "extra": True})
 
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 accepts_person({"name": "Alice", "age": 30, "extra": True})
 # TODO: this should be an error
 house.owner = {"name": "Alice", "age": 30, "extra": True}
 
 a_person: Person
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 a_person = {"name": "Alice", "age": 30, "extra": True}
-# error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extra""
 (a_person := {"name": "Alice", "age": 30, "extra": True})
 ```
 
@@ -323,7 +323,7 @@ user2 = User({"name": "Bob"})
 # error: [invalid-argument-type] "Invalid argument to key "name" with declared type `str` on TypedDict `User`: value of type `None`"
 user3 = User({"name": None, "age": 25})
 
-# error: [invalid-key] "Invalid key access on TypedDict `User`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `User`: Unknown key "extra""
 user4 = User({"name": "Charlie", "age": 30, "extra": True})
 ```
 
@@ -360,7 +360,7 @@ invalid = OptionalPerson(name=123)
 Extra fields are still not allowed, even with `total=False`:
 
 ```py
-# error: [invalid-key] "Invalid key access on TypedDict `OptionalPerson`: Unknown key "extra""
+# error: [invalid-key] "Invalid key for TypedDict `OptionalPerson`: Unknown key "extra""
 invalid_extra = OptionalPerson(name="George", extra=True)
 ```
 
@@ -503,10 +503,10 @@ def _(person: Person, literal_key: Literal["age"], union_of_keys: Literal["age",
 
     reveal_type(person[union_of_keys])  # revealed: int | None | str
 
-    # error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "non_existing""
+    # error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "non_existing""
     reveal_type(person["non_existing"])  # revealed: Unknown
 
-    # error: [invalid-key] "TypedDict `Person` cannot be indexed with a key of type `str`"
+    # error: [invalid-key] "Invalid key for TypedDict `Person` of type `str`"
     reveal_type(person[str_key])  # revealed: Unknown
 
     # No error here:
@@ -530,7 +530,7 @@ def _(person: Person):
     person["name"] = "Alice"
     person["age"] = 30
 
-    # error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "naem" - did you mean "name"?"
+    # error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "naem" - did you mean "name"?"
     person["naem"] = "Alice"
 
 def _(person: Person):
@@ -646,7 +646,7 @@ def _(p: Person) -> None:
     reveal_type(p.setdefault("name", "Alice"))  # revealed: str
     reveal_type(p.setdefault("extra", "default"))  # revealed: str
 
-    # error: [invalid-key] "Invalid key access on TypedDict `Person`: Unknown key "extraz" - did you mean "extra"?"
+    # error: [invalid-key] "Invalid key for TypedDict `Person`: Unknown key "extraz" - did you mean "extra"?"
     reveal_type(p.setdefault("extraz", "value"))  # revealed: Unknown
 ```
 
@@ -1015,6 +1015,10 @@ def write_to_non_existing_key(person: Person):
 
 def write_to_non_literal_string_key(person: Person, str_key: str):
     person[str_key] = "Alice"  # error: [invalid-key]
+
+def create_with_invalid_string_key():
+    alice: Person = {"name": "Alice", "age": 30, "unknown": "Foo"}  # error: [invalid-key]
+    bob = Person(name="Bob", age=25, unknown="Bar")  # error: [invalid-key]
 ```
 
 Assignment to `ReadOnly` keys:

crates/ty_python_semantic/src/semantic_index.rs

@@ -6,12 +6,12 @@ use ruff_db::parsed::parsed_module;
 use ruff_index::{IndexSlice, IndexVec};
 
 use ruff_python_ast::NodeIndex;
+use ruff_python_ast::name::Name;
 use ruff_python_parser::semantic_errors::SemanticSyntaxError;
 use rustc_hash::{FxHashMap, FxHashSet};
 use salsa::Update;
 use salsa::plumbing::AsId;
 
-use crate::Db;
 use crate::module_name::ModuleName;
 use crate::node_key::NodeKey;
 use crate::semantic_index::ast_ids::AstIds;
@@ -28,6 +28,7 @@ use crate::semantic_index::scope::{
 use crate::semantic_index::symbol::ScopedSymbolId;
 use crate::semantic_index::use_def::{EnclosingSnapshotKey, ScopedEnclosingSnapshotId, UseDefMap};
 use crate::semantic_model::HasTrackedScope;
+use crate::{Db, Module, resolve_module};
 
 pub mod ast_ids;
 mod builder;
@@ -75,20 +76,73 @@ pub(crate) fn place_table<'db>(db: &'db dyn Db, scope: ScopeId<'db>) -> Arc<Plac
 
 /// Returns the set of modules that are imported anywhere in `file`.
 ///
-/// This set only considers `import` statements, not `from...import` statements, because:
-///
-///   - In `from foo import bar`, we cannot determine whether `foo.bar` is a submodule (and is
-///     therefore imported) without looking outside the content of this file.  (We could turn this
-///     into a _potentially_ imported modules set, but that would change how it's used in our type
-///     inference logic.)
-///
-///   - 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.
+/// This set only considers `import` statements, not `from...import` statements.
+/// See [`ModuleLiteralType::available_submodule_attributes`] for discussion
+/// of why this analysis is intentionally limited.
 #[salsa::tracked(returns(deref), heap_size=ruff_memory_usage::heap_size)]
 pub(crate) fn imported_modules<'db>(db: &'db dyn Db, file: File) -> Arc<FxHashSet<ModuleName>> {
     semantic_index(db, file).imported_modules.clone()
 }
 
+/// Returns the set of relative submodules that are explicitly imported anywhere in
+/// `importing_module`.
+///
+/// This set only considers `from...import` statements (but it could also include `import`).
+/// It also only returns a non-empty result for `__init__.pyi` files.
+/// See [`ModuleLiteralType::available_submodule_attributes`] for discussion
+/// of why this analysis is intentionally limited.
+///
+/// This function specifically implements the rule that if an `__init__.pyi` file
+/// contains a `from...import` that imports a direct submodule of the package,
+/// that submodule should be available as an attribute of the package.
+///
+/// While we endeavour to accurately model import side-effects for `.py` files, we intentionally
+/// limit them for `.pyi` files to encourage more intentional API design. The standard escape
+/// hatches for this are the `import x as x` idiom or listing them in `__all__`, but in practice
+/// some other idioms are popular.
+///
+/// In particular, many packages have their `__init__` include lines like
+/// `from . import subpackage`, with the intent that `mypackage.subpackage` should be
+/// available for anyone who only does `import mypackage`.
+#[salsa::tracked(returns(deref), heap_size=ruff_memory_usage::heap_size)]
+pub(crate) fn imported_relative_submodules_of_stub_package<'db>(
+    db: &'db dyn Db,
+    importing_module: Module<'db>,
+) -> Box<[ModuleName]> {
+    let Some(file) = importing_module.file(db) else {
+        return Box::default();
+    };
+    if !file.is_package_stub(db) {
+        return Box::default();
+    }
+    semantic_index(db, file)
+        .maybe_imported_modules
+        .iter()
+        .filter_map(|import| {
+            let mut submodule = ModuleName::from_identifier_parts(
+                db,
+                file,
+                import.from_module.as_deref(),
+                import.level,
+            )
+            .ok()?;
+            // We only actually care if this is a direct submodule of the package
+            // so this part should actually be exactly the importing module.
+            let importing_module_name = importing_module.name(db);
+            if importing_module_name != &submodule {
+                return None;
+            }
+            submodule.extend(&ModuleName::new(import.submodule.as_str())?);
+            // Throw out the result if this doesn't resolve to an actual module.
+            // This is quite expensive, but we've gone through a lot of hoops to
+            // get here so it won't happen too much.
+            resolve_module(db, &submodule)?;
+            // Return only the relative part
+            submodule.relative_to(importing_module_name)
+        })
+        .collect()
+}
+
 /// Returns the use-def map for a specific `scope`.
 ///
 /// Using [`use_def_map`] over [`semantic_index`] has the advantage that
@@ -230,6 +284,9 @@ pub(crate) struct SemanticIndex<'db> {
     /// The set of modules that are imported anywhere within this file.
     imported_modules: Arc<FxHashSet<ModuleName>>,
 
+    /// `from...import` statements within this file that might import a submodule.
+    maybe_imported_modules: FxHashSet<MaybeModuleImport>,
+
     /// Flags about the global scope (code usage impacting inference)
     has_future_annotations: bool,
 
@@ -243,6 +300,16 @@ pub(crate) struct SemanticIndex<'db> {
     generator_functions: FxHashSet<FileScopeId>,
 }
 
+/// A `from...import` that may be an import of a module
+///
+/// Later analysis will determine if it is.
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, get_size2::GetSize)]
+pub(crate) struct MaybeModuleImport {
+    level: u32,
+    from_module: Option<Name>,
+    submodule: Name,
+}
+
 impl<'db> SemanticIndex<'db> {
     /// Returns the place table for a specific scope.
     ///

crates/ty_python_semantic/src/semantic_index/builder.rs

@@ -47,7 +47,9 @@ use crate::semantic_index::symbol::{ScopedSymbolId, Symbol};
 use crate::semantic_index::use_def::{
     EnclosingSnapshotKey, FlowSnapshot, ScopedEnclosingSnapshotId, UseDefMapBuilder,
 };
-use crate::semantic_index::{ExpressionsScopeMap, SemanticIndex, VisibleAncestorsIter};
+use crate::semantic_index::{
+    ExpressionsScopeMap, MaybeModuleImport, SemanticIndex, VisibleAncestorsIter,
+};
 use crate::semantic_model::HasTrackedScope;
 use crate::unpack::{EvaluationMode, Unpack, UnpackKind, UnpackPosition, UnpackValue};
 use crate::{Db, Program};
@@ -111,6 +113,7 @@ pub(super) struct SemanticIndexBuilder<'db, 'ast> {
     definitions_by_node: FxHashMap<DefinitionNodeKey, Definitions<'db>>,
     expressions_by_node: FxHashMap<ExpressionNodeKey, Expression<'db>>,
     imported_modules: FxHashSet<ModuleName>,
+    maybe_imported_modules: FxHashSet<MaybeModuleImport>,
     /// Hashset of all [`FileScopeId`]s that correspond to [generator functions].
     ///
     /// [generator functions]: https://docs.python.org/3/glossary.html#term-generator
@@ -148,6 +151,7 @@ impl<'db, 'ast> SemanticIndexBuilder<'db, 'ast> {
             definitions_by_node: FxHashMap::default(),
             expressions_by_node: FxHashMap::default(),
 
+            maybe_imported_modules: FxHashSet::default(),
             imported_modules: FxHashSet::default(),
             generator_functions: FxHashSet::default(),
 
@@ -1262,6 +1266,7 @@ impl<'db, 'ast> SemanticIndexBuilder<'db, 'ast> {
         self.scopes_by_node.shrink_to_fit();
         self.generator_functions.shrink_to_fit();
         self.enclosing_snapshots.shrink_to_fit();
+        self.maybe_imported_modules.shrink_to_fit();
 
         SemanticIndex {
             place_tables,
@@ -1274,6 +1279,7 @@ impl<'db, 'ast> SemanticIndexBuilder<'db, 'ast> {
             scopes_by_node: self.scopes_by_node,
             use_def_maps,
             imported_modules: Arc::new(self.imported_modules),
+            maybe_imported_modules: self.maybe_imported_modules,
             has_future_annotations: self.has_future_annotations,
             enclosing_snapshots: self.enclosing_snapshots,
             semantic_syntax_errors: self.semantic_syntax_errors.into_inner(),
@@ -1558,6 +1564,15 @@ impl<'ast> Visitor<'ast> for SemanticIndexBuilder<'_, 'ast> {
                         (&alias.name.id, false)
                     };
 
+                    // If there's no alias or a redundant alias, record this as a potential import of a submodule
+                    if alias.asname.is_none() || is_reexported {
+                        self.maybe_imported_modules.insert(MaybeModuleImport {
+                            level: node.level,
+                            from_module: node.module.clone().map(Into::into),
+                            submodule: alias.name.clone().into(),
+                        });
+                    }
+
                     // Look for imports `from __future__ import annotations`, ignore `as ...`
                     // We intentionally don't enforce the rules about location of `__future__`
                     // imports here, we assume the user's intent was to apply the `__future__`

crates/ty_python_semantic/src/types.rs

@@ -39,7 +39,9 @@ use crate::place::{
 use crate::semantic_index::definition::{Definition, DefinitionKind};
 use crate::semantic_index::place::ScopedPlaceId;
 use crate::semantic_index::scope::ScopeId;
-use crate::semantic_index::{imported_modules, place_table, semantic_index};
+use crate::semantic_index::{
+    imported_modules, imported_relative_submodules_of_stub_package, place_table, semantic_index,
+};
 use crate::suppression::check_suppressions;
 use crate::types::bound_super::BoundSuperType;
 use crate::types::call::{Binding, Bindings, CallArguments, CallableBinding};
@@ -889,13 +891,24 @@ impl<'db> Type<'db> {
         known_class: KnownClass,
     ) -> Option<Specialization<'db>> {
         let class_literal = known_class.try_to_class_literal(db)?;
-        self.specialization_of(db, Some(class_literal))
+        self.specialization_of(db, class_literal)
+    }
+
+    // If this type is a class instance, returns its specialization.
+    pub(crate) fn class_specialization(self, db: &'db dyn Db) -> Option<Specialization<'db>> {
+        self.specialization_of_optional(db, None)
     }
 
     // If the type is a specialized instance of the given class, returns the specialization.
-    //
-    // If no class is provided, returns the specialization of any class instance.
     pub(crate) fn specialization_of(
+        self,
+        db: &'db dyn Db,
+        expected_class: ClassLiteral<'_>,
+    ) -> Option<Specialization<'db>> {
+        self.specialization_of_optional(db, Some(expected_class))
+    }
+
+    fn specialization_of_optional(
         self,
         db: &'db dyn Db,
         expected_class: Option<ClassLiteral<'_>>,
@@ -1212,22 +1225,28 @@ impl<'db> Type<'db> {
 
     /// If the type is a union, filters union elements based on the provided predicate.
     ///
-    /// Otherwise, returns the type unchanged.
+    /// Otherwise, considers the type to be the sole inhabitant of a single-valued union,
+    /// and filters it, returning `Never` if the predicate returns `false`, or the type
+    /// unchanged if `true`.
     pub(crate) fn filter_union(
         self,
         db: &'db dyn Db,
-        f: impl FnMut(&Type<'db>) -> bool,
+        mut f: impl FnMut(&Type<'db>) -> bool,
     ) -> Type<'db> {
         if let Type::Union(union) = self {
             union.filter(db, f)
-        } else {
+        } else if f(&self) {
             self
+        } else {
+            Type::Never
         }
     }
 
     /// If the type is a union, removes union elements that are disjoint from `target`.
     ///
-    /// Otherwise, returns the type unchanged.
+    /// Otherwise, considers the type to be the sole inhabitant of a single-valued union,
+    /// and filters it, returning `Never` if it is disjoint from `target`, or the type
+    /// unchanged if `true`.
     pub(crate) fn filter_disjoint_elements(
         self,
         db: &'db dyn Db,
@@ -4159,6 +4178,14 @@ impl<'db> Type<'db> {
                 ))
                 .into()
             }
+            Type::KnownInstance(KnownInstanceType::ConstraintSet(tracked))
+                if name == "satisfied_by_all_typevars" =>
+            {
+                Place::bound(Type::KnownBoundMethod(
+                    KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(tracked),
+                ))
+                .into()
+            }
 
             Type::ClassLiteral(class)
                 if name == "__get__" && class.is_known(db, KnownClass::FunctionType) =>
@@ -6921,6 +6948,7 @@ impl<'db> Type<'db> {
                 | KnownBoundMethodType::ConstraintSetAlways
                 | KnownBoundMethodType::ConstraintSetNever
                 | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+                | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_)
             )
             | Type::DataclassDecorator(_)
             | Type::DataclassTransformer(_)
@@ -7072,7 +7100,8 @@ impl<'db> Type<'db> {
                 | KnownBoundMethodType::ConstraintSetRange
                 | KnownBoundMethodType::ConstraintSetAlways
                 | KnownBoundMethodType::ConstraintSetNever
-                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_),
+                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+                | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_),
             )
             | Type::DataclassDecorator(_)
             | Type::DataclassTransformer(_)
@@ -10337,6 +10366,7 @@ pub enum KnownBoundMethodType<'db> {
     ConstraintSetAlways,
     ConstraintSetNever,
     ConstraintSetImpliesSubtypeOf(TrackedConstraintSet<'db>),
+    ConstraintSetSatisfiedByAllTypeVars(TrackedConstraintSet<'db>),
 }
 
 pub(super) fn walk_method_wrapper_type<'db, V: visitor::TypeVisitor<'db> + ?Sized>(
@@ -10364,7 +10394,8 @@ pub(super) fn walk_method_wrapper_type<'db, V: visitor::TypeVisitor<'db> + ?Size
         | KnownBoundMethodType::ConstraintSetRange
         | KnownBoundMethodType::ConstraintSetAlways
         | KnownBoundMethodType::ConstraintSetNever
-        | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_) => {}
+        | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+        | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_) => {}
     }
 }
 
@@ -10432,6 +10463,10 @@ impl<'db> KnownBoundMethodType<'db> {
             | (
                 KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_),
                 KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_),
+            )
+            | (
+                KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_),
+                KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_),
             ) => ConstraintSet::from(true),
 
             (
@@ -10444,7 +10479,8 @@ impl<'db> KnownBoundMethodType<'db> {
                 | KnownBoundMethodType::ConstraintSetRange
                 | KnownBoundMethodType::ConstraintSetAlways
                 | KnownBoundMethodType::ConstraintSetNever
-                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_),
+                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+                | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_),
                 KnownBoundMethodType::FunctionTypeDunderGet(_)
                 | KnownBoundMethodType::FunctionTypeDunderCall(_)
                 | KnownBoundMethodType::PropertyDunderGet(_)
@@ -10454,7 +10490,8 @@ impl<'db> KnownBoundMethodType<'db> {
                 | KnownBoundMethodType::ConstraintSetRange
                 | KnownBoundMethodType::ConstraintSetAlways
                 | KnownBoundMethodType::ConstraintSetNever
-                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_),
+                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+                | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_),
             ) => ConstraintSet::from(false),
         }
     }
@@ -10507,6 +10544,10 @@ impl<'db> KnownBoundMethodType<'db> {
             (
                 KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(left_constraints),
                 KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(right_constraints),
+            )
+            | (
+                KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(left_constraints),
+                KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(right_constraints),
             ) => left_constraints
                 .constraints(db)
                 .iff(db, right_constraints.constraints(db)),
@@ -10521,7 +10562,8 @@ impl<'db> KnownBoundMethodType<'db> {
                 | KnownBoundMethodType::ConstraintSetRange
                 | KnownBoundMethodType::ConstraintSetAlways
                 | KnownBoundMethodType::ConstraintSetNever
-                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_),
+                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+                | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_),
                 KnownBoundMethodType::FunctionTypeDunderGet(_)
                 | KnownBoundMethodType::FunctionTypeDunderCall(_)
                 | KnownBoundMethodType::PropertyDunderGet(_)
@@ -10531,7 +10573,8 @@ impl<'db> KnownBoundMethodType<'db> {
                 | KnownBoundMethodType::ConstraintSetRange
                 | KnownBoundMethodType::ConstraintSetAlways
                 | KnownBoundMethodType::ConstraintSetNever
-                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_),
+                | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+                | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_),
             ) => ConstraintSet::from(false),
         }
     }
@@ -10555,7 +10598,8 @@ impl<'db> KnownBoundMethodType<'db> {
             | KnownBoundMethodType::ConstraintSetRange
             | KnownBoundMethodType::ConstraintSetAlways
             | KnownBoundMethodType::ConstraintSetNever
-            | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_) => self,
+            | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+            | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_) => self,
         }
     }
 
@@ -10571,7 +10615,10 @@ impl<'db> KnownBoundMethodType<'db> {
             KnownBoundMethodType::ConstraintSetRange
             | KnownBoundMethodType::ConstraintSetAlways
             | KnownBoundMethodType::ConstraintSetNever
-            | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_) => KnownClass::ConstraintSet,
+            | KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)
+            | KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_) => {
+                KnownClass::ConstraintSet
+            }
         }
     }
 
@@ -10710,6 +10757,19 @@ impl<'db> KnownBoundMethodType<'db> {
                     Some(KnownClass::ConstraintSet.to_instance(db)),
                 )))
             }
+
+            KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(_) => {
+                Either::Right(std::iter::once(Signature::new(
+                    Parameters::new([Parameter::keyword_only(Name::new_static("inferable"))
+                        .type_form()
+                        .with_annotated_type(UnionType::from_elements(
+                            db,
+                            [Type::homogeneous_tuple(db, Type::any()), Type::none(db)],
+                        ))
+                        .with_default_type(Type::none(db))]),
+                    Some(KnownClass::Bool.to_instance(db)),
+                )))
+            }
         }
     }
 }
@@ -10830,11 +10890,68 @@ impl<'db> ModuleLiteralType<'db> {
         self._importing_file(db)
     }
 
+    /// Get the submodule attributes we believe to be defined on this module.
+    ///
+    /// Note that `ModuleLiteralType` is per-importing-file, so this analysis
+    /// includes "imports the importing file has performed".
+    ///
+    ///
+    /// # Danger! Powerful Hammer!
+    ///
+    /// These results immediately make the attribute always defined in the importing file,
+    /// shadowing any other attribute in the module with the same name, even if the
+    /// non-submodule-attribute is in fact always the one defined in practice.
+    ///
+    /// Intuitively this means `available_submodule_attributes` "win all tie-breaks",
+    /// with the idea that if we're ever confused about complicated code then usually
+    /// the import is the thing people want in scope.
+    ///
+    /// However this "always defined, always shadows" rule if applied too aggressively
+    /// creates VERY confusing conclusions that break perfectly reasonable code.
+    ///
+    /// For instance, consider a package which has a `myfunc` submodule which defines a
+    /// `myfunc` function (a common idiom). If the package "re-exports" this function
+    /// (`from .myfunc import myfunc`), then at runtime in python
+    /// `from mypackage import myfunc` should import the function and not the submodule.
+    ///
+    /// However, if we were to consider `from mypackage import myfunc` as introducing
+    /// the attribute `mypackage.myfunc` in `available_submodule_attributes`, we would
+    /// fail to ever resolve the function. This is because `available_submodule_attributes`
+    /// is *so early* and *so powerful* in our analysis that **this conclusion would be
+    /// used when actually resolving `from mypackage import myfunc`**!
+    ///
+    /// This currently cannot be fixed by considering the actual symbols defined in `mypackage`,
+    /// because `available_submodule_attributes` is an *input* to that analysis.
+    ///
+    /// We should therefore avoid marking something as an `available_submodule_attribute`
+    /// when the import could be importing a non-submodule (a function, class, or value).
+    ///
+    ///
+    /// # Rules
+    ///
+    /// We have two rules for whether a submodule attribute is defined:
+    ///
+    /// * If the importing file include `import x.y` then `x.y` is defined in the importing file.
+    ///   This is an easy rule to justify because `import` can only ever import a module, and so
+    ///   *should* shadow any non-submodule of the same name.
+    ///
+    /// * If the module is an `__init__.pyi` for `mypackage`, and it contains a `from...import`
+    ///   that normalizes to `from mypackage import submodule`, then `mypackage.submodule` is
+    ///   defined in all files. This supports the `from . import submodule` idiom. Critically,
+    ///   we do *not* allow `from mypackage.nested import submodule` to affect `mypackage`.
+    ///   The idea here is that `from mypackage import submodule` *from mypackage itself* can
+    ///   only ever reasonably be an import of a submodule. It doesn't make any sense to import
+    ///   a function or class from yourself! (You *can* do it but... why? Don't? Please?)
     fn available_submodule_attributes(&self, db: &'db dyn Db) -> impl Iterator<Item = Name> {
         self.importing_file(db)
             .into_iter()
             .flat_map(|file| imported_modules(db, file))
             .filter_map(|submodule_name| submodule_name.relative_to(self.module(db).name(db)))
+            .chain(
+                imported_relative_submodules_of_stub_package(db, self.module(db))
+                    .iter()
+                    .cloned(),
+            )
             .filter_map(|relative_submodule| relative_submodule.components().next().map(Name::from))
     }
 

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

@@ -9,6 +9,7 @@ use std::fmt;
 use itertools::{Either, Itertools};
 use ruff_db::parsed::parsed_module;
 use ruff_python_ast::name::Name;
+use rustc_hash::FxHashSet;
 use smallvec::{SmallVec, smallvec, smallvec_inline};
 
 use super::{Argument, CallArguments, CallError, CallErrorKind, InferContext, Signature, Type};
@@ -34,10 +35,11 @@ use crate::types::generics::{
 use crate::types::signatures::{Parameter, ParameterForm, ParameterKind, Parameters};
 use crate::types::tuple::{TupleLength, TupleType};
 use crate::types::{
-    BoundMethodType, ClassLiteral, DataclassFlags, DataclassParams, FieldInstance,
-    KnownBoundMethodType, KnownClass, KnownInstanceType, MemberLookupPolicy, PropertyInstanceType,
-    SpecialFormType, TrackedConstraintSet, TypeAliasType, TypeContext, UnionBuilder, UnionType,
-    WrapperDescriptorKind, enums, ide_support, infer_isolated_expression, todo_type,
+    BoundMethodType, BoundTypeVarIdentity, ClassLiteral, DataclassFlags, DataclassParams,
+    FieldInstance, KnownBoundMethodType, KnownClass, KnownInstanceType, MemberLookupPolicy,
+    NominalInstanceType, PropertyInstanceType, SpecialFormType, TrackedConstraintSet,
+    TypeAliasType, TypeContext, UnionBuilder, UnionType, WrapperDescriptorKind, enums, ide_support,
+    infer_isolated_expression, todo_type,
 };
 use ruff_db::diagnostic::{Annotation, Diagnostic, SubDiagnostic, SubDiagnosticSeverity};
 use ruff_python_ast::{self as ast, ArgOrKeyword, PythonVersion};
@@ -1174,6 +1176,42 @@ impl<'db> Bindings<'db> {
                         ));
                     }
 
+                    Type::KnownBoundMethod(
+                        KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(tracked),
+                    ) => {
+                        let extract_inferable = |instance: &NominalInstanceType<'db>| {
+                            if instance.has_known_class(db, KnownClass::NoneType) {
+                                // Caller explicitly passed None, so no typevars are inferable.
+                                return Some(FxHashSet::default());
+                            }
+                            instance
+                                .tuple_spec(db)?
+                                .fixed_elements()
+                                .map(|ty| {
+                                    ty.as_typevar()
+                                        .map(|bound_typevar| bound_typevar.identity(db))
+                                })
+                                .collect()
+                        };
+
+                        let inferable = match overload.parameter_types() {
+                            // Caller did not provide argument, so no typevars are inferable.
+                            [None] => FxHashSet::default(),
+                            [Some(Type::NominalInstance(instance))] => {
+                                match extract_inferable(instance) {
+                                    Some(inferable) => inferable,
+                                    None => continue,
+                                }
+                            }
+                            _ => continue,
+                        };
+
+                        let result = tracked
+                            .constraints(db)
+                            .satisfied_by_all_typevars(db, InferableTypeVars::One(&inferable));
+                        overload.set_return_type(Type::BooleanLiteral(result));
+                    }
+
                     Type::ClassLiteral(class) => match class.known(db) {
                         Some(KnownClass::Bool) => match overload.parameter_types() {
                             [Some(arg)] => overload.set_return_type(arg.bool(db).into_type(db)),
@@ -2680,9 +2718,25 @@ impl<'a, 'db> ArgumentTypeChecker<'a, 'db> {
             return;
         };
 
+        let return_with_tcx = self
+            .signature
+            .return_ty
+            .zip(self.call_expression_tcx.annotation);
+
         self.inferable_typevars = generic_context.inferable_typevars(self.db);
         let mut builder = SpecializationBuilder::new(self.db, self.inferable_typevars);
 
+        // Prefer the declared type of generic classes.
+        let preferred_type_mappings = return_with_tcx.and_then(|(return_ty, tcx)| {
+            let preferred_return_ty =
+                tcx.filter_union(self.db, |ty| ty.class_specialization(self.db).is_some());
+            let return_ty =
+                return_ty.filter_union(self.db, |ty| ty.class_specialization(self.db).is_some());
+
+            builder.infer(return_ty, preferred_return_ty).ok()?;
+            Some(builder.type_mappings().clone())
+        });
+
         let parameters = self.signature.parameters();
         for (argument_index, adjusted_argument_index, _, argument_type) in
             self.enumerate_argument_types()
@@ -2695,9 +2749,21 @@ impl<'a, 'db> ArgumentTypeChecker<'a, 'db> {
                     continue;
                 };
 
-                if let Err(error) = builder.infer(
+                let filter = |declared_ty: BoundTypeVarIdentity<'_>, inferred_ty: Type<'_>| {
+                    // Avoid widening the inferred type if it is already assignable to the
+                    // preferred declared type.
+                    preferred_type_mappings
+                        .as_ref()
+                        .and_then(|types| types.get(&declared_ty))
+                        .is_none_or(|preferred_ty| {
+                            !inferred_ty.is_assignable_to(self.db, *preferred_ty)
+                        })
+                };
+
+                if let Err(error) = builder.infer_filter(
                     expected_type,
                     variadic_argument_type.unwrap_or(argument_type),
+                    filter,
                 ) {
                     self.errors.push(BindingError::SpecializationError {
                         error,
@@ -2707,15 +2773,14 @@ impl<'a, 'db> ArgumentTypeChecker<'a, 'db> {
             }
         }
 
-        // Build the specialization first without inferring the type context.
+        // Build the specialization first without inferring the complete type context.
         let isolated_specialization = builder.build(generic_context, *self.call_expression_tcx);
         let isolated_return_ty = self
             .return_ty
             .apply_specialization(self.db, isolated_specialization);
 
         let mut try_infer_tcx = || {
-            let return_ty = self.signature.return_ty?;
-            let call_expression_tcx = self.call_expression_tcx.annotation?;
+            let (return_ty, call_expression_tcx) = return_with_tcx?;
 
             // A type variable is not a useful type-context for expression inference, and applying it
             // to the return type can lead to confusing unions in nested generic calls.
@@ -2724,7 +2789,7 @@ impl<'a, 'db> ArgumentTypeChecker<'a, 'db> {
             }
 
             // If the return type is already assignable to the annotated type, we can ignore the
-            // type context and prefer the narrower inferred type.
+            // rest of the type context and prefer the narrower inferred type.
             if isolated_return_ty.is_assignable_to(self.db, call_expression_tcx) {
                 return None;
             }
@@ -2733,7 +2798,7 @@ impl<'a, 'db> ArgumentTypeChecker<'a, 'db> {
             // annotated assignment, to closer match the order of any unions written in the type annotation.
             builder.infer(return_ty, call_expression_tcx).ok()?;
 
-            // Otherwise, build the specialization again after inferring the type context.
+            // Otherwise, build the specialization again after inferring the complete type context.
             let specialization = builder.build(generic_context, *self.call_expression_tcx);
             let return_ty = return_ty.apply_specialization(self.db, specialization);
 

crates/ty_python_semantic/src/types/class.rs

@@ -258,7 +258,7 @@ impl<'db> GenericAlias<'db> {
     ) -> Self {
         let tcx = tcx
             .annotation
-            .and_then(|ty| ty.specialization_of(db, Some(self.origin(db))))
+            .and_then(|ty| ty.specialization_of(db, self.origin(db)))
             .map(|specialization| specialization.types(db))
             .unwrap_or(&[]);
 
@@ -637,12 +637,17 @@ impl<'db> ClassType<'db> {
             return true;
         }
 
-        // Optimisation: if either class is `@final`, we only need to do one `is_subclass_of` call.
         if self.is_final(db) {
-            return self.is_subclass_of(db, other);
+            return self
+                .iter_mro(db)
+                .filter_map(ClassBase::into_class)
+                .any(|class| class.class_literal(db).0 == other.class_literal(db).0);
         }
         if other.is_final(db) {
-            return other.is_subclass_of(db, self);
+            return other
+                .iter_mro(db)
+                .filter_map(ClassBase::into_class)
+                .any(|class| class.class_literal(db).0 == self.class_literal(db).0);
         }
 
         // Two disjoint bases can only coexist in an MRO if one is a subclass of the other.
@@ -2176,7 +2181,8 @@ impl<'db> ClassLiteral<'db> {
         });
 
         if member.is_undefined() {
-            if let Some(synthesized_member) = self.own_synthesized_member(db, specialization, name)
+            if let Some(synthesized_member) =
+                self.own_synthesized_member(db, specialization, inherited_generic_context, name)
             {
                 return Member::definitely_declared(synthesized_member);
             }
@@ -2192,6 +2198,7 @@ impl<'db> ClassLiteral<'db> {
         self,
         db: &'db dyn Db,
         specialization: Option<Specialization<'db>>,
+        inherited_generic_context: Option<GenericContext<'db>>,
         name: &str,
     ) -> Option<Type<'db>> {
         let dataclass_params = self.dataclass_params(db);
@@ -2320,7 +2327,7 @@ impl<'db> ClassLiteral<'db> {
 
             let signature = match name {
                 "__new__" | "__init__" => Signature::new_generic(
-                    self.inherited_generic_context(db),
+                    inherited_generic_context.or_else(|| self.inherited_generic_context(db)),
                     Parameters::new(parameters),
                     return_ty,
                 ),
@@ -2702,7 +2709,7 @@ impl<'db> ClassLiteral<'db> {
         name: &str,
         policy: MemberLookupPolicy,
     ) -> PlaceAndQualifiers<'db> {
-        if let Some(member) = self.own_synthesized_member(db, specialization, name) {
+        if let Some(member) = self.own_synthesized_member(db, specialization, None, name) {
             Place::bound(member).into()
         } else {
             KnownClass::TypedDictFallback

crates/ty_python_semantic/src/types/constraints.rs

@@ -65,7 +65,10 @@ use salsa::plumbing::AsId;
 
 use crate::Db;
 use crate::types::generics::InferableTypeVars;
-use crate::types::{BoundTypeVarInstance, IntersectionType, Type, TypeRelation, UnionType};
+use crate::types::{
+    BoundTypeVarInstance, IntersectionType, Type, TypeRelation, TypeVarBoundOrConstraints,
+    UnionType,
+};
 
 /// An extension trait for building constraint sets from [`Option`] values.
 pub(crate) trait OptionConstraintsExtension<T> {
@@ -256,6 +259,28 @@ impl<'db> ConstraintSet<'db> {
         }
     }
 
+    /// Returns whether this constraint set is satisfied by all of the typevars that it mentions.
+    ///
+    /// Each typevar has a set of _valid specializations_, which is defined by any upper bound or
+    /// constraints that the typevar has.
+    ///
+    /// Each typevar is also either _inferable_ or _non-inferable_. (You provide a list of the
+    /// `inferable` typevars; all others are considered non-inferable.) For an inferable typevar,
+    /// then there must be _some_ valid specialization that satisfies the constraint set. For a
+    /// non-inferable typevar, then _all_ valid specializations must satisfy it.
+    ///
+    /// Note that we don't have to consider typevars that aren't mentioned in the constraint set,
+    /// since the constraint set cannot be affected by any typevars that it does not mention. That
+    /// means that those additional typevars trivially satisfy the constraint set, regardless of
+    /// whether they are inferable or not.
+    pub(crate) fn satisfied_by_all_typevars(
+        self,
+        db: &'db dyn Db,
+        inferable: InferableTypeVars<'_, 'db>,
+    ) -> bool {
+        self.node.satisfied_by_all_typevars(db, inferable)
+    }
+
     /// Updates this constraint set to hold the union of itself and another constraint set.
     pub(crate) fn union(&mut self, db: &'db dyn Db, other: Self) -> Self {
         self.node = self.node.or(db, other.node);
@@ -746,6 +771,13 @@ impl<'db> Node<'db> {
             .or(db, self.negate(db).and(db, else_node))
     }
 
+    fn satisfies(self, db: &'db dyn Db, other: Self) -> Self {
+        let simplified_self = self.simplify(db);
+        let implication = simplified_self.implies(db, other);
+        let (simplified, domain) = implication.simplify_and_domain(db);
+        simplified.and(db, domain)
+    }
+
     fn when_subtype_of_given(
         self,
         db: &'db dyn Db,
@@ -767,10 +799,48 @@ impl<'db> Node<'db> {
             _ => return lhs.when_subtype_of(db, rhs, inferable).node,
         };
 
-        let simplified_self = self.simplify(db);
-        let implication = simplified_self.implies(db, constraint);
-        let (simplified, domain) = implication.simplify_and_domain(db);
-        simplified.and(db, domain)
+        self.satisfies(db, constraint)
+    }
+
+    fn satisfied_by_all_typevars(
+        self,
+        db: &'db dyn Db,
+        inferable: InferableTypeVars<'_, 'db>,
+    ) -> bool {
+        match self {
+            Node::AlwaysTrue => return true,
+            Node::AlwaysFalse => return false,
+            Node::Interior(_) => {}
+        }
+
+        let mut typevars = FxHashSet::default();
+        self.for_each_constraint(db, &mut |constraint| {
+            typevars.insert(constraint.typevar(db));
+        });
+
+        for typevar in typevars {
+            // Determine which valid specializations of this typevar satisfy the constraint set.
+            let valid_specializations = typevar.valid_specializations(db).node;
+            let when_satisfied = valid_specializations
+                .satisfies(db, self)
+                .and(db, valid_specializations);
+            let satisfied = if typevar.is_inferable(db, inferable) {
+                // If the typevar is inferable, then we only need one valid specialization to
+                // satisfy the constraint set.
+                !when_satisfied.is_never_satisfied()
+            } else {
+                // If the typevar is non-inferable, then we need _all_ valid specializations to
+                // satisfy the constraint set.
+                when_satisfied
+                    .iff(db, valid_specializations)
+                    .is_always_satisfied(db)
+            };
+            if !satisfied {
+                return false;
+            }
+        }
+
+        true
     }
 
     /// Returns a new BDD that returns the same results as `self`, but with some inputs fixed to
@@ -1861,6 +1931,33 @@ impl<'db> SatisfiedClauses<'db> {
     }
 }
 
+/// Returns a constraint set describing the valid specializations of a typevar.
+impl<'db> BoundTypeVarInstance<'db> {
+    pub(crate) fn valid_specializations(self, db: &'db dyn Db) -> ConstraintSet<'db> {
+        match self.typevar(db).bound_or_constraints(db) {
+            None => ConstraintSet::from(true),
+            Some(TypeVarBoundOrConstraints::UpperBound(bound)) => ConstraintSet::constrain_typevar(
+                db,
+                self,
+                Type::Never,
+                bound,
+                TypeRelation::Assignability,
+            ),
+            Some(TypeVarBoundOrConstraints::Constraints(constraints)) => {
+                constraints.elements(db).iter().when_any(db, |constraint| {
+                    ConstraintSet::constrain_typevar(
+                        db,
+                        self,
+                        *constraint,
+                        *constraint,
+                        TypeRelation::Assignability,
+                    )
+                })
+            }
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/ty_python_semantic/src/types/diagnostic.rs

@@ -572,10 +572,14 @@ declare_lint! {
 // Added in #19763.
 declare_lint! {
     /// ## What it does
-    /// Checks for subscript accesses with invalid keys.
+    /// Checks for subscript accesses with invalid keys and `TypedDict` construction with an
+    /// unknown key.
     ///
     /// ## Why is this bad?
-    /// Using an invalid key will raise a `KeyError` at runtime.
+    /// Subscripting with an invalid key will raise a `KeyError` at runtime.
+    ///
+    /// Creating a `TypedDict` with an unknown key is likely a mistake; if the `TypedDict` is
+    /// `closed=true` it also violates the expectations of the type.
     ///
     /// ## Examples
     /// ```python
@@ -587,9 +591,13 @@ declare_lint! {
     ///
     /// alice = Person(name="Alice", age=30)
     /// alice["height"]  # KeyError: 'height'
+    ///
+    /// bob: Person = { "name": "Bob", "age": 30 }  # typo!
+    ///
+    /// carol = Person(name="Carol", age=25)  # typo!
     /// ```
     pub(crate) static INVALID_KEY = {
-        summary: "detects invalid subscript accesses",
+        summary: "detects invalid subscript accesses or TypedDict literal keys",
         status: LintStatus::stable("0.0.1-alpha.17"),
         default_level: Level::Error,
     }
@@ -2966,7 +2974,7 @@ pub(crate) fn report_invalid_key_on_typed_dict<'db>(
                 let typed_dict_name = typed_dict_ty.display(db);
 
                 let mut diagnostic = builder.into_diagnostic(format_args!(
-                    "Invalid key access on TypedDict `{typed_dict_name}`",
+                    "Invalid key for TypedDict `{typed_dict_name}`",
                 ));
 
                 diagnostic.annotate(
@@ -2989,7 +2997,7 @@ pub(crate) fn report_invalid_key_on_typed_dict<'db>(
                 diagnostic
             }
             _ => builder.into_diagnostic(format_args!(
-                "TypedDict `{}` cannot be indexed with a key of type `{}`",
+                "Invalid key for TypedDict `{}` of type `{}`",
                 typed_dict_ty.display(db),
                 key_ty.display(db),
             )),

crates/ty_python_semantic/src/types/display.rs

@@ -535,6 +535,9 @@ impl Display for DisplayRepresentation<'_> {
             Type::KnownBoundMethod(KnownBoundMethodType::ConstraintSetImpliesSubtypeOf(_)) => {
                 f.write_str("bound method `ConstraintSet.implies_subtype_of`")
             }
+            Type::KnownBoundMethod(KnownBoundMethodType::ConstraintSetSatisfiedByAllTypeVars(
+                _,
+            )) => f.write_str("bound method `ConstraintSet.satisfied_by_all_typevars`"),
             Type::WrapperDescriptor(kind) => {
                 let (method, object) = match kind {
                     WrapperDescriptorKind::FunctionTypeDunderGet => ("__get__", "function"),

crates/ty_python_semantic/src/types/generics.rs

@@ -1,4 +1,5 @@
 use std::cell::RefCell;
+use std::collections::hash_map::Entry;
 use std::fmt::Display;
 
 use itertools::Itertools;
@@ -1319,6 +1320,11 @@ impl<'db> SpecializationBuilder<'db> {
         }
     }
 
+    /// Returns the current set of type mappings for this specialization.
+    pub(crate) fn type_mappings(&self) -> &FxHashMap<BoundTypeVarIdentity<'db>, Type<'db>> {
+        &self.types
+    }
+
     pub(crate) fn build(
         &mut self,
         generic_context: GenericContext<'db>,
@@ -1326,7 +1332,7 @@ impl<'db> SpecializationBuilder<'db> {
     ) -> Specialization<'db> {
         let tcx_specialization = tcx
             .annotation
-            .and_then(|annotation| annotation.specialization_of(self.db, None));
+            .and_then(|annotation| annotation.class_specialization(self.db));
 
         let types =
             (generic_context.variables_inner(self.db).iter()).map(|(identity, variable)| {
@@ -1349,19 +1355,43 @@ impl<'db> SpecializationBuilder<'db> {
         generic_context.specialize_partial(self.db, types)
     }
 
-    fn add_type_mapping(&mut self, bound_typevar: BoundTypeVarInstance<'db>, ty: Type<'db>) {
-        self.types
-            .entry(bound_typevar.identity(self.db))
-            .and_modify(|existing| {
-                *existing = UnionType::from_elements(self.db, [*existing, ty]);
-            })
-            .or_insert(ty);
+    fn add_type_mapping(
+        &mut self,
+        bound_typevar: BoundTypeVarInstance<'db>,
+        ty: Type<'db>,
+        filter: impl Fn(BoundTypeVarIdentity<'db>, Type<'db>) -> bool,
+    ) {
+        let identity = bound_typevar.identity(self.db);
+        match self.types.entry(identity) {
+            Entry::Occupied(mut entry) => {
+                if filter(identity, ty) {
+                    *entry.get_mut() = UnionType::from_elements(self.db, [*entry.get(), ty]);
+                }
+            }
+            Entry::Vacant(entry) => {
+                entry.insert(ty);
+            }
+        }
     }
 
+    /// Infer type mappings for the specialization based on a given type and its declared type.
     pub(crate) fn infer(
         &mut self,
         formal: Type<'db>,
         actual: Type<'db>,
+    ) -> Result<(), SpecializationError<'db>> {
+        self.infer_filter(formal, actual, |_, _| true)
+    }
+
+    /// Infer type mappings for the specialization based on a given type and its declared type.
+    ///
+    /// The filter predicate is provided with a type variable and the type being mapped to it. Type
+    /// mappings to which the predicate returns `false` will be ignored.
+    pub(crate) fn infer_filter(
+        &mut self,
+        formal: Type<'db>,
+        actual: Type<'db>,
+        filter: impl Fn(BoundTypeVarIdentity<'db>, Type<'db>) -> bool,
     ) -> Result<(), SpecializationError<'db>> {
         if formal == actual {
             return Ok(());
@@ -1442,7 +1472,7 @@ impl<'db> SpecializationBuilder<'db> {
                 if remaining_actual.is_never() {
                     return Ok(());
                 }
-                self.add_type_mapping(*formal_bound_typevar, remaining_actual);
+                self.add_type_mapping(*formal_bound_typevar, remaining_actual, filter);
             }
             (Type::Union(formal), _) => {
                 // Second, if the formal is a union, and precisely one union element _is_ a typevar (not
@@ -1452,7 +1482,7 @@ impl<'db> SpecializationBuilder<'db> {
                 let bound_typevars =
                     (formal.elements(self.db).iter()).filter_map(|ty| ty.as_typevar());
                 if let Ok(bound_typevar) = bound_typevars.exactly_one() {
-                    self.add_type_mapping(bound_typevar, actual);
+                    self.add_type_mapping(bound_typevar, actual, filter);
                 }
             }
 
@@ -1480,15 +1510,23 @@ impl<'db> SpecializationBuilder<'db> {
                                 argument: ty,
                             });
                         }
-                        self.add_type_mapping(bound_typevar, ty);
+                        self.add_type_mapping(bound_typevar, ty, filter);
                     }
                     Some(TypeVarBoundOrConstraints::Constraints(constraints)) => {
+                        // Prefer an exact match first.
+                        for constraint in constraints.elements(self.db) {
+                            if ty == *constraint {
+                                self.add_type_mapping(bound_typevar, ty, filter);
+                                return Ok(());
+                            }
+                        }
+
                         for constraint in constraints.elements(self.db) {
                             if ty
                                 .when_assignable_to(self.db, *constraint, self.inferable)
                                 .is_always_satisfied(self.db)
                             {
-                                self.add_type_mapping(bound_typevar, *constraint);
+                                self.add_type_mapping(bound_typevar, *constraint, filter);
                                 return Ok(());
                             }
                         }
@@ -1498,7 +1536,7 @@ impl<'db> SpecializationBuilder<'db> {
                         });
                     }
                     _ => {
-                        self.add_type_mapping(bound_typevar, ty);
+                        self.add_type_mapping(bound_typevar, ty, filter);
                     }
                 }
             }

crates/ty_python_semantic/src/types/infer/builder.rs

@@ -6260,7 +6260,8 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
 
                 let inferred_elt_ty = self.get_or_infer_expression(elt, elt_tcx);
 
-                // Simplify the inference based on the declared type of the element.
+                // Avoid widening the inferred type if it is already assignable to the preferred
+                // declared type.
                 if let Some(elt_tcx) = elt_tcx.annotation {
                     if inferred_elt_ty.is_assignable_to(self.db(), elt_tcx) {
                         continue;

crates/ty_vendored/ty_extensions/ty_extensions.pyi

@@ -67,6 +67,16 @@ class ConstraintSet:
         .. _subtype: https://typing.python.org/en/latest/spec/concepts.html#subtype-supertype-and-type-equivalence
         """
 
+    def satisfied_by_all_typevars(
+        self, *, inferable: tuple[Any, ...] | None = None
+    ) -> bool:
+        """
+        Returns whether this constraint set is satisfied by all of the typevars
+        that it mentions. You must provide a tuple of the typevars that should
+        be considered `inferable`. All other typevars mentioned in the
+        constraint set will be considered non-inferable.
+        """
+
     def __bool__(self) -> bool: ...
     def __eq__(self, other: ConstraintSet) -> bool: ...
     def __ne__(self, other: ConstraintSet) -> bool: ...

docs/integrations.md

@@ -80,7 +80,7 @@ You can add the following configuration to `.gitlab-ci.yml` to run a `ruff forma
   stage: build
   interruptible: true
   image:
-    name: ghcr.io/astral-sh/ruff:0.14.2-alpine
+    name: ghcr.io/astral-sh/ruff:0.14.3-alpine
   before_script:
     - cd $CI_PROJECT_DIR
     - ruff --version
@@ -106,7 +106,7 @@ Ruff can be used as a [pre-commit](https://pre-commit.com) hook via [`ruff-pre-c
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.14.2
+  rev: v0.14.3
   hooks:
     # Run the linter.
     - id: ruff-check
@@ -119,7 +119,7 @@ To enable lint fixes, add the `--fix` argument to the lint hook:
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.14.2
+  rev: v0.14.3
   hooks:
     # Run the linter.
     - id: ruff-check
@@ -133,7 +133,7 @@ To avoid running on Jupyter Notebooks, remove `jupyter` from the list of allowed
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.14.2
+  rev: v0.14.3
   hooks:
     # Run the linter.
     - id: ruff-check

docs/tutorial.md

@@ -369,7 +369,7 @@ This tutorial has focused on Ruff's command-line interface, but Ruff can also be
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.14.2
+  rev: v0.14.3
   hooks:
     # Run the linter.
     - id: ruff

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "maturin"
 
 [project]
 name = "ruff"
-version = "0.14.2"
+version = "0.14.3"
 description = "An extremely fast Python linter and code formatter, written in Rust."
 authors = [{ name = "Astral Software Inc.", email = "hey@astral.sh" }]
 readme = "README.md"

scripts/benchmarks/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "scripts"
-version = "0.14.2"
+version = "0.14.3"
 description = ""
 authors = ["Charles Marsh <charlie.r.marsh@gmail.com>"]
 

scripts/release.sh

@@ -12,7 +12,7 @@ project_root="$(dirname "$script_root")"
 echo "Updating metadata with rooster..."
 cd "$project_root"
 uvx --python 3.12 --isolated -- \
-    rooster@0.1.0 release "$@"
+    rooster@0.1.1 release "$@"
 
 echo "Updating lockfile..."
 cargo update -p ruff

ty.schema.json

@@ -584,8 +584,8 @@
           ]
         },
         "invalid-key": {
-          "title": "detects invalid subscript accesses",
-          "description": "## What it does\nChecks for subscript accesses with invalid keys.\n\n## Why is this bad?\nUsing an invalid key will raise a `KeyError` at runtime.\n\n## Examples\n```python\nfrom typing import TypedDict\n\nclass Person(TypedDict):\n    name: str\n    age: int\n\nalice = Person(name=\"Alice\", age=30)\nalice[\"height\"]  # KeyError: 'height'\n```",
+          "title": "detects invalid subscript accesses or TypedDict literal keys",
+          "description": "## What it does\nChecks for subscript accesses with invalid keys and `TypedDict` construction with an\nunknown key.\n\n## Why is this bad?\nSubscripting with an invalid key will raise a `KeyError` at runtime.\n\nCreating a `TypedDict` with an unknown key is likely a mistake; if the `TypedDict` is\n`closed=true` it also violates the expectations of the type.\n\n## Examples\n```python\nfrom typing import TypedDict\n\nclass Person(TypedDict):\n    name: str\n    age: int\n\nalice = Person(name=\"Alice\", age=30)\nalice[\"height\"]  # KeyError: 'height'\n\nbob: Person = { \"name\": \"Bob\", \"age\": 30 }  # typo!\n\ncarol = Person(name=\"Carol\", age=25)  # typo!\n```",
           "default": "error",
           "oneOf": [
             {