Use internal Salsa APIs to make it compile

## Summary

This PR reworks our ecosystem-analyzer workflow so that it automatically
reruns if a PR with the `ecosystem-analyzer` label has new commits
pushed to it, or is reopened after previously being closed. It's
currently easy to forget that you need to remove and re-add the label to
trigger a fresh workflow run, which can then mean that there are stale
(misleading) results in the PR comment posted by the bot. It also means
that it takes longer for CI to finish than it would otherwise, because
it might be a few minutes after pushing new commits to the PR before you
remember that you also need to remove and re-add the label.

To write this PR, I consulted:
- The GitHub workflow trigger documentation:
https://docs.github.com/en/actions/reference/workflows-and-actions/events-that-trigger-workflows#pull_request
- This Stack Overflow answer:
https://stackoverflow.com/a/59588725/13990016

## Test Plan

I experimented with pushing commits to this PR and closing/reopening it,
and both of these actions triggered fresh runs of the ecosystem-analyzer
worfklow when the label was present on the PR. However, removing the
label again meant that the workflow was no longer triggered by these
actions.

.github/actionlint.yaml

@@ -4,10 +4,12 @@
 self-hosted-runner:
   # Various runners we use that aren't recognized out-of-the-box by actionlint:
   labels:
+    - depot-ubuntu-24.04-4
     - depot-ubuntu-latest-8
     - depot-ubuntu-22.04-16
     - depot-ubuntu-22.04-32
     - depot-windows-2022-16
+    - depot-ubuntu-22.04-arm-4
     - github-windows-2025-x86_64-8
     - github-windows-2025-x86_64-16
     - codspeed-macro

.github/workflows/ci.yaml

@@ -952,7 +952,7 @@ jobs:
           tool: cargo-codspeed
 
       - name: "Build benchmarks"
-        run: cargo codspeed build --features "codspeed,instrumented" --profile profiling --no-default-features -p ruff_benchmark --bench formatter --bench lexer --bench linter --bench parser
+        run: cargo codspeed build --features "codspeed,ruff_instrumented" --profile profiling --no-default-features -p ruff_benchmark --bench formatter --bench lexer --bench linter --bench parser
 
       - name: "Run benchmarks"
         uses: CodSpeedHQ/action@346a2d8a8d9d38909abd0bc3d23f773110f076ad # v4.4.1
@@ -960,9 +960,9 @@ jobs:
           mode: simulation
           run: cargo codspeed run
 
-  benchmarks-instrumented-ty:
-    name: "benchmarks instrumented (ty)"
-    runs-on: ubuntu-24.04
+  benchmarks-instrumented-ty-build:
+    name: "benchmarks instrumented ty (build)"
+    runs-on: depot-ubuntu-24.04-4
     needs: determine_changes
     if: |
       github.repository == 'astral-sh/ruff' &&
@@ -971,9 +971,83 @@ jobs:
         needs.determine_changes.outputs.ty == 'true'
       )
     timeout-minutes: 20
+    steps:
+      - name: "Checkout Branch"
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+
+      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
+        with:
+          save-if: ${{ github.ref == 'refs/heads/main' }}
+
+      - name: "Install Rust toolchain"
+        run: rustup show
+
+      - name: "Install codspeed"
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
+        with:
+          tool: cargo-codspeed
+
+      - name: "Build benchmarks"
+        run: cargo codspeed build -m instrumentation --features "codspeed,ty_instrumented" --profile profiling --no-default-features -p ruff_benchmark --bench ty
+
+      - name: "Upload benchmark binary"
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        with:
+          name: benchmarks-instrumented-ty-binary
+          path: target/codspeed/simulation/ruff_benchmark
+          retention-days: 1
+
+  benchmarks-instrumented-ty-run:
+    name: "benchmarks instrumented ty (${{ matrix.benchmark }})"
+    runs-on: ubuntu-24.04
+    needs: benchmarks-instrumented-ty-build
+    timeout-minutes: 20
     permissions:
       contents: read # required for actions/checkout
       id-token: write # required for OIDC authentication with CodSpeed
+    strategy:
+      fail-fast: false
+      matrix:
+        benchmark:
+          - "check_file|micro|anyio"
+          - "attrs|hydra|datetype"
+    steps:
+      - name: "Checkout Branch"
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          persist-credentials: false
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
+
+      - name: "Install codspeed"
+        uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
+        with:
+          tool: cargo-codspeed
+
+      - name: "Download benchmark binary"
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v4.3.0
+        with:
+          name: benchmarks-instrumented-ty-binary
+          path: target/codspeed/simulation/ruff_benchmark
+
+      - name: "Restore binary permissions"
+        run: chmod +x target/codspeed/simulation/ruff_benchmark/ty
+
+      - name: "Run benchmarks"
+        uses: CodSpeedHQ/action@346a2d8a8d9d38909abd0bc3d23f773110f076ad # v4.4.1
+        with:
+          mode: simulation
+          run: cargo codspeed run --bench ty "${{ matrix.benchmark }}"
+
+  benchmarks-walltime-build:
+    name: "benchmarks walltime (build)"
+    # We only run this job if `github.repository == 'astral-sh/ruff'`,
+    # so hardcoding depot here is fine
+    runs-on: depot-ubuntu-22.04-arm-4
+    needs: determine_changes
+    if: ${{ github.repository == 'astral-sh/ruff' && !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.ty == 'true' || github.ref == 'refs/heads/main') }}
+    timeout-minutes: 20
     steps:
       - name: "Checkout Branch"
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
@@ -994,49 +1068,51 @@ jobs:
           tool: cargo-codspeed
 
       - name: "Build benchmarks"
-        run: cargo codspeed build --features "codspeed,instrumented" --profile profiling --no-default-features -p ruff_benchmark --bench ty
+        run: cargo codspeed build -m walltime --features "codspeed,ty_walltime" --profile profiling --no-default-features -p ruff_benchmark
 
-      - name: "Run benchmarks"
-        uses: CodSpeedHQ/action@346a2d8a8d9d38909abd0bc3d23f773110f076ad # v4.4.1
+      - name: "Upload benchmark binary"
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
-          mode: simulation
-          run: cargo codspeed run
+          name: benchmarks-walltime-binary
+          path: target/codspeed/walltime/ruff_benchmark
+          retention-days: 1
 
-  benchmarks-walltime:
-    name: "benchmarks walltime (${{ matrix.benchmarks }})"
+  benchmarks-walltime-run:
+    name: "benchmarks walltime (${{ matrix.benchmark }})"
     runs-on: codspeed-macro
-    needs: determine_changes
-    if: ${{ github.repository == 'astral-sh/ruff' && !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.ty == 'true' || github.ref == 'refs/heads/main') }}
+    needs: benchmarks-walltime-build
     timeout-minutes: 20
     permissions:
       contents: read # required for actions/checkout
       id-token: write # required for OIDC authentication with CodSpeed
     strategy:
       matrix:
-        benchmarks:
-          - "medium|multithreaded"
-          - "small|large"
+        benchmark:
+          - colour_science
+          - "pandas|tanjun|altair"
+          - "static_frame|sympy"
+          - "pydantic|multithreaded|freqtrade"
     steps:
       - name: "Checkout Branch"
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
 
-      - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
-        with:
-          save-if: ${{ github.ref == 'refs/heads/main' }}
       - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
-      - name: "Install Rust toolchain"
-        run: rustup show
-
       - name: "Install codspeed"
         uses: taiki-e/install-action@3575e532701a5fc614b0c842e4119af4cc5fd16d # v2.62.60
         with:
           tool: cargo-codspeed
 
-      - name: "Build benchmarks"
-        run: cargo codspeed build --features "codspeed,walltime" --profile profiling --no-default-features -p ruff_benchmark
+      - name: "Download benchmark binary"
+        uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
+        with:
+          name: benchmarks-walltime-binary
+          path: target/codspeed/walltime/ruff_benchmark
+
+      - name: "Restore binary permissions"
+        run: chmod +x target/codspeed/walltime/ruff_benchmark/ty_walltime
 
       - name: "Run benchmarks"
         uses: CodSpeedHQ/action@346a2d8a8d9d38909abd0bc3d23f773110f076ad # v4.4.1
@@ -1047,4 +1123,4 @@ jobs:
           CODSPEED_PERF_ENABLED: false
         with:
           mode: walltime
-          run: cargo codspeed run --bench ty_walltime "${{ matrix.benchmarks }}"
+          run: cargo codspeed run --bench ty_walltime -m walltime "${{ matrix.benchmark }}"

.github/workflows/ty-ecosystem-analyzer.yaml

@@ -4,7 +4,13 @@ permissions: {}
 
 on:
   pull_request:
-    types: [labeled]
+    # The default for `pull_request` is to trigger on `synchronize`, `opened` and `reopened`.
+    # We also add `labeled` here so that the workflow triggers when a label is initially added.
+    types:
+      - labeled
+      - synchronize
+      - opened
+      - reopened
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.sha }}
@@ -23,7 +29,7 @@ jobs:
     name: Compute diagnostic diff
     runs-on: ${{ github.repository == 'astral-sh/ruff' && 'depot-ubuntu-22.04-32' || 'ubuntu-latest' }}
     timeout-minutes: 20
-    if: contains(github.event.label.name, 'ecosystem-analyzer')
+    if: contains( github.event.pull_request.labels.*.name, 'ecosystem-analyzer')
     steps:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:

.github/workflows/ty-ecosystem-report.yaml

@@ -1,3 +1,7 @@
+# This workflow is a cron job that generates a report describing
+# all diagnostics ty emits across the whole ecosystem. The report
+# is uploaded to https://ty-ecosystem-ext.pages.dev/ on a weekly basis.
+
 name: ty ecosystem-report
 
 permissions: {}
@@ -14,7 +18,6 @@ env:
   CARGO_TERM_COLOR: always
   RUSTUP_MAX_RETRIES: 10
   RUST_BACKTRACE: 1
-  CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
 
 jobs:
   ty-ecosystem-report:
@@ -31,12 +34,12 @@ jobs:
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
-          enable-cache: true # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact
+          enable-cache: true
 
       - uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5 # v2.8.2
         with:
           workspaces: "ruff"
-          lookup-only: false # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact
+          lookup-only: false
 
       - name: Install Rust toolchain
         run: rustup show
@@ -70,11 +73,10 @@ jobs:
             ecosystem-diagnostics.json \
             --output dist/index.html
 
-      - name: "Deploy to Cloudflare Pages"
-        if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        id: deploy
-        uses: cloudflare/wrangler-action@da0e0dfe58b7a431659754fdf3f186c529afbe65 # v3.14.1
+      # NOTE: astral-sh-bot uses this artifact to publish the ecosystem report.
+      # Make sure to update the bot if you rename the artifact.
+      - name: "Upload ecosystem report"
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
         with:
-          apiToken: ${{ secrets.CF_API_TOKEN }}
-          accountId: ${{ secrets.CF_ACCOUNT_ID }}
-          command: pages deploy dist --project-name=ty-ecosystem --branch main --commit-hash ${GITHUB_SHA}
+          name: full-report
+          path: dist/

Cargo.lock

@@ -3129,6 +3129,7 @@ dependencies = [
  "salsa",
  "schemars",
  "serde",
+ "ty_module_resolver",
  "ty_python_semantic",
  "zip",
 ]
@@ -3619,8 +3620,8 @@ checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
 
 [[package]]
 name = "salsa"
-version = "0.24.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=55e5e7d32fa3fc189276f35bb04c9438f9aedbd1#55e5e7d32fa3fc189276f35bb04c9438f9aedbd1"
+version = "0.25.2"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=0298d2951e45ccf1450f1a09fb379dc7e48ddee9#0298d2951e45ccf1450f1a09fb379dc7e48ddee9"
 dependencies = [
  "boxcar",
  "compact_str",
@@ -3644,13 +3645,13 @@ dependencies = [
 
 [[package]]
 name = "salsa-macro-rules"
-version = "0.24.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=55e5e7d32fa3fc189276f35bb04c9438f9aedbd1#55e5e7d32fa3fc189276f35bb04c9438f9aedbd1"
+version = "0.25.2"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=0298d2951e45ccf1450f1a09fb379dc7e48ddee9#0298d2951e45ccf1450f1a09fb379dc7e48ddee9"
 
 [[package]]
 name = "salsa-macros"
-version = "0.24.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=55e5e7d32fa3fc189276f35bb04c9438f9aedbd1#55e5e7d32fa3fc189276f35bb04c9438f9aedbd1"
+version = "0.25.2"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=0298d2951e45ccf1450f1a09fb379dc7e48ddee9#0298d2951e45ccf1450f1a09fb379dc7e48ddee9"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4375,6 +4376,7 @@ dependencies = [
  "tracing-flame",
  "tracing-subscriber",
  "ty_combine",
+ "ty_module_resolver",
  "ty_project",
  "ty_python_semantic",
  "ty_server",
@@ -4389,7 +4391,6 @@ dependencies = [
  "ordermap",
  "ruff_db",
  "ruff_python_ast",
- "ty_python_semantic",
 ]
 
 [[package]]
@@ -4407,8 +4408,8 @@ dependencies = [
  "tempfile",
  "toml",
  "ty_ide",
+ "ty_module_resolver",
  "ty_project",
- "ty_python_semantic",
  "walkdir",
 ]
 
@@ -4438,11 +4439,35 @@ dependencies = [
  "salsa",
  "smallvec",
  "tracing",
+ "ty_module_resolver",
  "ty_project",
  "ty_python_semantic",
  "ty_vendored",
 ]
 
+[[package]]
+name = "ty_module_resolver"
+version = "0.0.0"
+dependencies = [
+ "anyhow",
+ "camino",
+ "compact_str",
+ "get-size2",
+ "insta",
+ "ruff_db",
+ "ruff_memory_usage",
+ "ruff_python_ast",
+ "ruff_python_stdlib",
+ "rustc-hash",
+ "salsa",
+ "strum",
+ "strum_macros",
+ "tempfile",
+ "thiserror 2.0.17",
+ "tracing",
+ "ty_vendored",
+]
+
 [[package]]
 name = "ty_project"
 version = "0.0.0"
@@ -4477,6 +4502,7 @@ dependencies = [
  "toml",
  "tracing",
  "ty_combine",
+ "ty_module_resolver",
  "ty_python_semantic",
  "ty_static",
  "ty_vendored",
@@ -4529,11 +4555,11 @@ dependencies = [
  "strsim",
  "strum",
  "strum_macros",
- "tempfile",
  "test-case",
  "thiserror 2.0.17",
  "tracing",
- "ty_python_semantic",
+ "ty_combine",
+ "ty_module_resolver",
  "ty_static",
  "ty_test",
  "ty_vendored",
@@ -4572,6 +4598,7 @@ dependencies = [
  "tracing-subscriber",
  "ty_combine",
  "ty_ide",
+ "ty_module_resolver",
  "ty_project",
  "ty_python_semantic",
 ]
@@ -4612,6 +4639,7 @@ dependencies = [
  "thiserror 2.0.17",
  "toml",
  "tracing",
+ "ty_module_resolver",
  "ty_python_semantic",
  "ty_static",
  "ty_vendored",

Cargo.toml

@@ -45,6 +45,7 @@ ty = { path = "crates/ty" }
 ty_combine = { path = "crates/ty_combine" }
 ty_completion_eval = { path = "crates/ty_completion_eval" }
 ty_ide = { path = "crates/ty_ide" }
+ty_module_resolver = { path = "crates/ty_module_resolver" }
 ty_project = { path = "crates/ty_project", default-features = false }
 ty_python_semantic = { path = "crates/ty_python_semantic" }
 ty_server = { path = "crates/ty_server" }
@@ -146,7 +147,7 @@ regex-automata = { version = "0.4.9" }
 rustc-hash = { version = "2.0.0" }
 rustc-stable-hash = { version = "0.1.2" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "55e5e7d32fa3fc189276f35bb04c9438f9aedbd1", default-features = false, features = [
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "0298d2951e45ccf1450f1a09fb379dc7e48ddee9", default-features = false, features = [
     "compact_str",
     "macros",
     "salsa_unstable",

crates/ruff/tests/cli/snapshots/cli__format__output_format_github.snap

@@ -14,6 +14,6 @@ info:
 success: false
 exit_code: 1
 ----- stdout -----
-::error title=Ruff (unformatted),file=[TMP]/input.py,line=1,col=1,endLine=2,endColumn=1::input.py:1:1: unformatted: File would be reformatted
+::error title=Ruff (unformatted),file=[TMP]/input.py,line=1,endLine=2::input.py:1:1: unformatted: File would be reformatted
 
 ----- stderr -----

crates/ruff_benchmark/Cargo.toml

@@ -19,32 +19,32 @@ doctest = false
 [[bench]]
 name = "linter"
 harness = false
-required-features = ["instrumented"]
+required-features = ["ruff_instrumented"]
 
 [[bench]]
 name = "lexer"
 harness = false
-required-features = ["instrumented"]
+required-features = ["ruff_instrumented"]
 
 [[bench]]
 name = "parser"
 harness = false
-required-features = ["instrumented"]
+required-features = ["ruff_instrumented"]
 
 [[bench]]
 name = "formatter"
 harness = false
-required-features = ["instrumented"]
+required-features = ["ruff_instrumented"]
 
 [[bench]]
 name = "ty"
 harness = false
-required-features = ["instrumented"]
+required-features = ["ty_instrumented"]
 
 [[bench]]
 name = "ty_walltime"
 harness = false
-required-features = ["walltime"]
+required-features = ["ty_walltime"]
 
 [dependencies]
 ruff_db = { workspace = true, features = ["testing"] }
@@ -67,25 +67,32 @@ tracing = { workspace = true }
 workspace = true
 
 [features]
-default = ["instrumented", "walltime"]
-# Enables the benchmark that should only run with codspeed's instrumented runner
-instrumented = [
+default = ["ty_instrumented", "ty_walltime", "ruff_instrumented"]
+# Enables the ruff instrumented benchmarks
+ruff_instrumented = [
     "criterion",
     "ruff_linter",
     "ruff_python_formatter",
     "ruff_python_parser",
     "ruff_python_trivia",
+    "mimalloc",
+    "tikv-jemallocator",
+]
+# Enables the ty instrumented benchmarks
+ty_instrumented = [
+    "criterion",
     "ty_project",
+    "ruff_python_trivia",
 ]
 codspeed = ["codspeed-criterion-compat"]
-# Enables benchmark that should only run with codspeed's walltime runner.
-walltime = ["ruff_db/os", "ty_project", "divan"]
+# Enables the ty_walltime benchmarks
+ty_walltime = ["ruff_db/os", "ty_project", "divan"]
 
-[target.'cfg(target_os = "windows")'.dev-dependencies]
-mimalloc = { workspace = true }
+[target.'cfg(target_os = "windows")'.dependencies]
+mimalloc = { workspace = true, optional = true }
 
-[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64", target_arch = "riscv64")))'.dev-dependencies]
-tikv-jemallocator = { workspace = true }
+[target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64", target_arch = "riscv64")))'.dependencies]
+tikv-jemallocator = { workspace = true, optional = true }
 
 [dev-dependencies]
 rustc-hash = { workspace = true }

crates/ruff_benchmark/benches/ty_walltime.rs

@@ -194,7 +194,7 @@ static SYMPY: Benchmark = Benchmark::new(
         max_dep_date: "2025-06-17",
         python_version: PythonVersion::PY312,
     },
-    13100,
+    13106,
 );
 
 static TANJUN: Benchmark = Benchmark::new(
@@ -235,30 +235,55 @@ fn run_single_threaded(bencher: Bencher, benchmark: &Benchmark) {
         });
 }
 
-#[bench(args=[&ALTAIR, &FREQTRADE, &TANJUN], sample_size=2, sample_count=3)]
-fn small(bencher: Bencher, benchmark: &Benchmark) {
-    run_single_threaded(bencher, benchmark);
+#[bench(sample_size = 2, sample_count = 3)]
+fn altair(bencher: Bencher) {
+    run_single_threaded(bencher, &ALTAIR);
 }
 
-#[bench(args=[&COLOUR_SCIENCE, &PANDAS, &STATIC_FRAME], sample_size=1, sample_count=3)]
-fn medium(bencher: Bencher, benchmark: &Benchmark) {
-    run_single_threaded(bencher, benchmark);
+#[bench(sample_size = 2, sample_count = 3)]
+fn freqtrade(bencher: Bencher) {
+    run_single_threaded(bencher, &FREQTRADE);
 }
 
-#[bench(args=[&SYMPY, &PYDANTIC], sample_size=1, sample_count=2)]
-fn large(bencher: Bencher, benchmark: &Benchmark) {
-    run_single_threaded(bencher, benchmark);
+#[bench(sample_size = 2, sample_count = 3)]
+fn tanjun(bencher: Bencher) {
+    run_single_threaded(bencher, &TANJUN);
 }
 
-#[bench(args=[&ALTAIR], sample_size=3, sample_count=8)]
-fn multithreaded(bencher: Bencher, benchmark: &Benchmark) {
+#[bench(sample_size = 2, sample_count = 3)]
+fn pydantic(bencher: Bencher) {
+    run_single_threaded(bencher, &PYDANTIC);
+}
+
+#[bench(sample_size = 1, sample_count = 3)]
+fn static_frame(bencher: Bencher) {
+    run_single_threaded(bencher, &STATIC_FRAME);
+}
+
+#[bench(sample_size = 1, sample_count = 2)]
+fn colour_science(bencher: Bencher) {
+    run_single_threaded(bencher, &COLOUR_SCIENCE);
+}
+
+#[bench(sample_size = 1, sample_count = 2)]
+fn pandas(bencher: Bencher) {
+    run_single_threaded(bencher, &PANDAS);
+}
+
+#[bench(sample_size = 1, sample_count = 2)]
+fn sympy(bencher: Bencher) {
+    run_single_threaded(bencher, &SYMPY);
+}
+
+#[bench(sample_size = 3, sample_count = 8)]
+fn multithreaded(bencher: Bencher) {
     let thread_pool = ThreadPoolBuilder::new().build().unwrap();
 
     bencher
-        .with_inputs(|| benchmark.setup_iteration())
+        .with_inputs(|| ALTAIR.setup_iteration())
         .bench_local_values(|db| {
             thread_pool.install(|| {
-                check_project(&db, benchmark.project.name, benchmark.max_diagnostics);
+                check_project(&db, ALTAIR.project.name, ALTAIR.max_diagnostics);
                 db
             })
         });

crates/ruff_benchmark/src/lib.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-#[cfg(feature = "instrumented")]
+#[cfg(any(feature = "ty_instrumented", feature = "ruff_instrumented"))]
 pub mod criterion;
 pub mod real_world_projects;
 

crates/ruff_db/src/cancellation.rs

@@ -0,0 +1,51 @@
+use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
+
+/// Signals a [`CancellationToken`] that it should be canceled.
+#[derive(Debug, Clone)]
+pub struct CancellationTokenSource {
+    cancelled: Arc<AtomicBool>,
+}
+
+impl Default for CancellationTokenSource {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl CancellationTokenSource {
+    pub fn new() -> Self {
+        Self {
+            cancelled: Arc::new(AtomicBool::new(false)),
+        }
+    }
+
+    pub fn is_cancellation_requested(&self) -> bool {
+        self.cancelled.load(std::sync::atomic::Ordering::Relaxed)
+    }
+
+    /// Creates a new token that uses this source.
+    pub fn token(&self) -> CancellationToken {
+        CancellationToken {
+            cancelled: self.cancelled.clone(),
+        }
+    }
+
+    /// Requests cancellation for operations using this token.
+    pub fn cancel(&self) {
+        self.cancelled
+            .store(true, std::sync::atomic::Ordering::Relaxed);
+    }
+}
+
+/// Token signals whether an operation should be canceled.
+#[derive(Debug, Clone)]
+pub struct CancellationToken {
+    cancelled: Arc<AtomicBool>,
+}
+
+impl CancellationToken {
+    pub fn is_cancelled(&self) -> bool {
+        self.cancelled.load(std::sync::atomic::Ordering::Relaxed)
+    }
+}

crates/ruff_db/src/diagnostic/mod.rs

@@ -1,4 +1,4 @@
-use std::{fmt::Formatter, path::Path, sync::Arc};
+use std::{borrow::Cow, fmt::Formatter, path::Path, sync::Arc};
 
 use ruff_diagnostics::{Applicability, Fix};
 use ruff_source_file::{LineColumn, SourceCode, SourceFile};
@@ -11,6 +11,7 @@ pub use self::render::{
     ceil_char_boundary,
     github::{DisplayGithubDiagnostics, GithubRenderer},
 };
+use crate::cancellation::CancellationToken;
 use crate::{Db, files::File};
 
 mod render;
@@ -410,11 +411,6 @@ impl Diagnostic {
         self.id().is_invalid_syntax()
     }
 
-    /// Returns the message body to display to the user.
-    pub fn body(&self) -> &str {
-        self.primary_message()
-    }
-
     /// Returns the message of the first sub-diagnostic with a `Help` severity.
     ///
     /// Note that this is used as the fix title/suggestion for some of Ruff's output formats, but in
@@ -1312,6 +1308,8 @@ pub struct DisplayDiagnosticConfig {
     show_fix_diff: bool,
     /// The lowest applicability that should be shown when reporting diagnostics.
     fix_applicability: Applicability,
+
+    cancellation_token: Option<CancellationToken>,
 }
 
 impl DisplayDiagnosticConfig {
@@ -1385,6 +1383,20 @@ impl DisplayDiagnosticConfig {
     pub fn fix_applicability(&self) -> Applicability {
         self.fix_applicability
     }
+
+    pub fn with_cancellation_token(
+        mut self,
+        token: Option<CancellationToken>,
+    ) -> DisplayDiagnosticConfig {
+        self.cancellation_token = token;
+        self
+    }
+
+    pub fn is_canceled(&self) -> bool {
+        self.cancellation_token
+            .as_ref()
+            .is_some_and(|token| token.is_cancelled())
+    }
 }
 
 impl Default for DisplayDiagnosticConfig {
@@ -1398,6 +1410,7 @@ impl Default for DisplayDiagnosticConfig {
             show_fix_status: false,
             show_fix_diff: false,
             fix_applicability: Applicability::Safe,
+            cancellation_token: None,
         }
     }
 }
@@ -1474,6 +1487,15 @@ pub enum ConciseMessage<'a> {
     Custom(&'a str),
 }
 
+impl<'a> ConciseMessage<'a> {
+    pub fn to_str(&self) -> Cow<'a, str> {
+        match self {
+            ConciseMessage::MainDiagnostic(s) | ConciseMessage::Custom(s) => Cow::Borrowed(s),
+            ConciseMessage::Both { .. } => Cow::Owned(self.to_string()),
+        }
+    }
+}
+
 impl std::fmt::Display for ConciseMessage<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         match *self {
@@ -1490,6 +1512,16 @@ impl std::fmt::Display for ConciseMessage<'_> {
     }
 }
 
+#[cfg(feature = "serde")]
+impl serde::Serialize for ConciseMessage<'_> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.collect_str(self)
+    }
+}
+
 /// A diagnostic message string.
 ///
 /// This is, for all intents and purposes, equivalent to a `Box<str>`.

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

@@ -52,7 +52,7 @@ impl AzureRenderer<'_> {
                 f,
                 "code={code};]{body}",
                 code = diag.secondary_code_or_id(),
-                body = diag.body(),
+                body = diag.concise_message(),
             )?;
         }
 

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

@@ -28,6 +28,10 @@ impl<'a> ConciseRenderer<'a> {
 
         let sep = fmt_styled(":", stylesheet.separator);
         for diag in diagnostics {
+            if self.config.is_canceled() {
+                return Ok(());
+            }
+
             if let Some(span) = diag.primary_span() {
                 write!(
                     f,

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

@@ -53,6 +53,10 @@ impl<'a> FullRenderer<'a> {
             .hyperlink(stylesheet.hyperlink);
 
         for diag in diagnostics {
+            if self.config.is_canceled() {
+                return Ok(());
+            }
+
             let resolved = Resolved::new(self.resolver, diag, self.config);
             let renderable = resolved.to_renderable(self.config.context);
             for diag in renderable.diagnostics.iter() {

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

@@ -49,14 +49,26 @@ impl<'a> GithubRenderer<'a> {
                 }
                 .unwrap_or_default();
 
-                write!(
-                    f,
-                    ",line={row},col={column},endLine={end_row},endColumn={end_column}::",
-                    row = start_location.line,
-                    column = start_location.column,
-                    end_row = end_location.line,
-                    end_column = end_location.column,
-                )?;
+                // GitHub Actions workflow commands have constraints on error annotations:
+                // - `col` and `endColumn` cannot be set if `line` and `endLine` are different
+                // See: https://github.com/astral-sh/ruff/issues/22074
+                if start_location.line == end_location.line {
+                    write!(
+                        f,
+                        ",line={row},col={column},endLine={end_row},endColumn={end_column}::",
+                        row = start_location.line,
+                        column = start_location.column,
+                        end_row = end_location.line,
+                        end_column = end_location.column,
+                    )?;
+                } else {
+                    write!(
+                        f,
+                        ",line={row},endLine={end_row}::",
+                        row = start_location.line,
+                        end_row = end_location.line,
+                    )?;
+                }
 
                 write!(
                     f,
@@ -75,7 +87,7 @@ impl<'a> GithubRenderer<'a> {
                 write!(f, "{id}:", id = diagnostic.id())?;
             }
 
-            writeln!(f, " {}", diagnostic.body())?;
+            writeln!(f, " {}", diagnostic.concise_message())?;
         }
 
         Ok(())

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

@@ -98,7 +98,7 @@ impl Serialize for SerializedMessages<'_> {
             }
             fingerprints.insert(message_fingerprint);
 
-            let description = diagnostic.body();
+            let description = diagnostic.concise_message();
             let check_name = diagnostic.secondary_code_or_id();
             let severity = match diagnostic.severity() {
                 Severity::Info => "info",

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

@@ -6,7 +6,7 @@ use ruff_notebook::NotebookIndex;
 use ruff_source_file::{LineColumn, OneIndexed};
 use ruff_text_size::Ranged;
 
-use crate::diagnostic::{Diagnostic, DiagnosticSource, DisplayDiagnosticConfig};
+use crate::diagnostic::{ConciseMessage, Diagnostic, DiagnosticSource, DisplayDiagnosticConfig};
 
 use super::FileResolver;
 
@@ -101,7 +101,7 @@ pub(super) fn diagnostic_to_json<'a>(
         JsonDiagnostic {
             code: diagnostic.secondary_code_or_id(),
             url: diagnostic.documentation_url(),
-            message: diagnostic.body(),
+            message: diagnostic.concise_message(),
             fix,
             cell: notebook_cell_index,
             location: start_location.map(JsonLocation::from),
@@ -113,7 +113,7 @@ pub(super) fn diagnostic_to_json<'a>(
         JsonDiagnostic {
             code: diagnostic.secondary_code_or_id(),
             url: diagnostic.documentation_url(),
-            message: diagnostic.body(),
+            message: diagnostic.concise_message(),
             fix,
             cell: notebook_cell_index,
             location: Some(start_location.unwrap_or_default().into()),
@@ -226,7 +226,7 @@ pub(crate) struct JsonDiagnostic<'a> {
     filename: Option<&'a str>,
     fix: Option<JsonFix<'a>>,
     location: Option<JsonLocation>,
-    message: &'a str,
+    message: ConciseMessage<'a>,
     noqa_row: Option<OneIndexed>,
     url: Option<&'a str>,
 }

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

@@ -56,17 +56,17 @@ impl<'a> JunitRenderer<'a> {
                         start_location: location,
                     } = diagnostic;
                     let mut status = TestCaseStatus::non_success(NonSuccessKind::Failure);
-                    status.set_message(diagnostic.body());
+                    status.set_message(diagnostic.concise_message().to_str());
 
                     if let Some(location) = location {
                         status.set_description(format!(
                             "line {row}, col {col}, {body}",
                             row = location.line,
                             col = location.column,
-                            body = diagnostic.body()
+                            body = diagnostic.concise_message()
                         ));
                     } else {
-                        status.set_description(diagnostic.body());
+                        status.set_description(diagnostic.concise_message().to_str());
                     }
 
                     let code = diagnostic

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

@@ -55,7 +55,7 @@ impl PylintRenderer<'_> {
                 f,
                 "{path}:{row}: [{code}] {body}",
                 path = filename,
-                body = diagnostic.body()
+                body = diagnostic.concise_message()
             )?;
         }
 

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

@@ -5,7 +5,7 @@ use ruff_diagnostics::{Edit, Fix};
 use ruff_source_file::{LineColumn, SourceCode};
 use ruff_text_size::Ranged;
 
-use crate::diagnostic::Diagnostic;
+use crate::diagnostic::{ConciseMessage, Diagnostic};
 
 use super::FileResolver;
 
@@ -76,7 +76,7 @@ fn diagnostic_to_rdjson<'a>(
     let edits = diagnostic.fix().map(Fix::edits).unwrap_or_default();
 
     RdjsonDiagnostic {
-        message: diagnostic.body(),
+        message: diagnostic.concise_message(),
         location,
         code: RdjsonCode {
             value: diagnostic
@@ -155,7 +155,7 @@ struct RdjsonDiagnostic<'a> {
     code: RdjsonCode<'a>,
     #[serde(skip_serializing_if = "Option::is_none")]
     location: Option<RdjsonLocation<'a>>,
-    message: &'a str,
+    message: ConciseMessage<'a>,
     #[serde(skip_serializing_if = "Vec::is_empty")]
     suggestions: Vec<RdjsonSuggestion<'a>>,
 }

crates/ruff_db/src/diagnostic/render/snapshots/ruff_db__diagnostic__render__github__tests__syntax_errors.snap

@@ -2,5 +2,5 @@
 source: crates/ruff_db/src/diagnostic/render/github.rs
 expression: env.render_diagnostics(&diagnostics)
 ---
-::error title=ty (invalid-syntax),file=/syntax_errors.py,line=1,col=15,endLine=2,endColumn=1::syntax_errors.py:1:15: invalid-syntax: Expected one or more symbol names after import
-::error title=ty (invalid-syntax),file=/syntax_errors.py,line=3,col=12,endLine=4,endColumn=1::syntax_errors.py:3:12: invalid-syntax: Expected ')', found newline
+::error title=ty (invalid-syntax),file=/syntax_errors.py,line=1,endLine=2::syntax_errors.py:1:15: invalid-syntax: Expected one or more symbol names after import
+::error title=ty (invalid-syntax),file=/syntax_errors.py,line=3,endLine=4::syntax_errors.py:3:12: invalid-syntax: Expected ')', found newline

crates/ruff_db/src/lib.rs

@@ -12,6 +12,7 @@ use std::hash::BuildHasherDefault;
 use std::num::NonZeroUsize;
 use ty_static::EnvVars;
 
+pub mod cancellation;
 pub mod diagnostic;
 pub mod display;
 pub mod file_revision;

crates/ruff_db/src/system/os.rs

@@ -275,16 +275,16 @@ impl OsSystem {
     /// instead of at least one system call for each component between `path` and `prefix`.
     ///
     /// However, using `canonicalize` to resolve the path's casing doesn't work in two cases:
-    /// * if `path` is a symlink because `canonicalize` then returns the symlink's target and not the symlink's source path.
-    /// * on Windows: If `path` is a mapped network drive because `canonicalize` then returns the UNC path
-    ///   (e.g. `Z:\` is mapped to `\\server\share` and `canonicalize` then returns `\\?\UNC\server\share`).
+    /// * if `path` is a symlink, `canonicalize` returns the symlink's target and not the symlink's source path.
+    /// * on Windows: If `path` is a mapped network drive, `canonicalize` returns the UNC path
+    ///   (e.g. `Z:\` is mapped to `\\server\share` and `canonicalize` returns `\\?\UNC\server\share`).
     ///
     /// Symlinks and mapped network drives should be rare enough that this fast path is worth trying first,
     /// even if it comes at a cost for those rare use cases.
     fn path_exists_case_sensitive_fast(&self, path: &SystemPath) -> Option<bool> {
         // This is a more forgiving version of `dunce::simplified` that removes all `\\?\` prefixes on Windows.
         // We use this more forgiving version because we don't intend on using either path for anything other than comparison
-        // and the prefix is only relevant when passing the path to other programs and its longer than 200 something
+        // and the prefix is only relevant when passing the path to other programs and it's longer than 200 something
         // characters.
         fn simplify_ignore_verbatim(path: &SystemPath) -> &SystemPath {
             if cfg!(windows) {
@@ -298,9 +298,7 @@ impl OsSystem {
             }
         }
 
-        let simplified = simplify_ignore_verbatim(path);
-
-        let Ok(canonicalized) = simplified.as_std_path().canonicalize() else {
+        let Ok(canonicalized) = path.as_std_path().canonicalize() else {
             // The path doesn't exist or can't be accessed. The path doesn't exist.
             return Some(false);
         };
@@ -309,12 +307,13 @@ impl OsSystem {
             // The original path is valid UTF8 but the canonicalized path isn't. This definitely suggests
             // that a symlink is involved. Fall back to the slow path.
             tracing::debug!(
-                "Falling back to the slow case-sensitive path existence check because the canonicalized path of `{simplified}` is not valid UTF-8"
+                "Falling back to the slow case-sensitive path existence check because the canonicalized path of `{path}` is not valid UTF-8"
             );
             return None;
         };
 
         let simplified_canonicalized = simplify_ignore_verbatim(&canonicalized);
+        let simplified = simplify_ignore_verbatim(path);
 
         // Test if the paths differ by anything other than casing. If so, that suggests that
         // `path` pointed to a symlink (or some other none reversible path normalization happened).

crates/ruff_db/src/testing.rs

@@ -37,7 +37,7 @@ pub fn assert_const_function_query_was_not_run<Db, Q, QDb, R>(
 
     let event = events.iter().find(|event| {
         if let salsa::EventKind::WillExecute { database_key } = event.kind {
-            db.ingredient_debug_name(database_key.ingredient_index()) == query_name
+            db.ingredient_debug_name(database_key.ingredient_index(db.zalsa())) == query_name
         } else {
             false
         }
@@ -89,7 +89,7 @@ where
 
     let event = events.iter().find(|event| {
         if let salsa::EventKind::WillExecute { database_key } = event.kind {
-            db.ingredient_debug_name(database_key.ingredient_index()) == query_name
+            db.ingredient_debug_name(database_key.ingredient_index(db.zalsa())) == query_name
                 && database_key.key_index() == input.as_id()
         } else {
             false

crates/ruff_dev/src/generate_ty_options.rs

@@ -1,11 +1,13 @@
 //! Generate a Markdown-compatible listing of configuration options for `pyproject.toml`.
 
+use std::borrow::Cow;
+use std::{fmt::Write, path::PathBuf};
+
 use anyhow::bail;
 use itertools::Itertools;
 use pretty_assertions::StrComparison;
-use std::{fmt::Write, path::PathBuf};
-
 use ruff_options_metadata::{OptionField, OptionSet, OptionsMetadata, Visit};
+use ruff_python_trivia::textwrap;
 use ty_project::metadata::Options;
 
 use crate::{
@@ -165,62 +167,69 @@ fn emit_field(output: &mut String, name: &str, field: &OptionField, parents: &[S
     let _ = writeln!(output, "**Default value**: `{}`", field.default);
     output.push('\n');
     let _ = writeln!(output, "**Type**: `{}`", field.value_type);
+
     output.push('\n');
     output.push_str("**Example usage**:\n\n");
-    output.push_str(&format_example(
-        "pyproject.toml",
-        &format_header(
-            field.scope,
-            field.example,
-            parents,
-            ConfigurationFile::PyprojectToml,
-        ),
-        field.example,
-    ));
-    output.push('\n');
-}
 
-fn format_example(title: &str, header: &str, content: &str) -> String {
-    if header.is_empty() {
-        format!("```toml title=\"{title}\"\n{content}\n```\n",)
-    } else {
-        format!("```toml title=\"{title}\"\n{header}\n{content}\n```\n",)
+    for configuration_file in [ConfigurationFile::PyprojectToml, ConfigurationFile::TyToml] {
+        let (header, example) =
+            format_snippet(field.scope, field.example, parents, configuration_file);
+        output.push_str(&format_tab(configuration_file.name(), &header, &example));
+
+        output.push('\n');
     }
 }
 
+fn format_tab(tab_name: &str, header: &str, content: &str) -> String {
+    let header = if header.is_empty() {
+        String::new()
+    } else {
+        format!("\n    {header}")
+    };
+    format!(
+        "=== \"{}\"\n\n    ```toml{}\n{}\n    ```\n",
+        tab_name,
+        header,
+        textwrap::indent(content, "    ")
+    )
+}
 /// Format the TOML header for the example usage for a given option.
 ///
-/// For example: `[tool.ruff.format]` or `[tool.ruff.lint.isort]`.
-fn format_header(
+/// For example: `[tool.ty.rules]`.
+fn format_snippet<'a>(
     scope: Option<&str>,
-    example: &str,
+    example: &'a str,
     parents: &[Set],
     configuration: ConfigurationFile,
-) -> String {
-    let tool_parent = match configuration {
-        ConfigurationFile::PyprojectToml => Some("tool.ty"),
-        ConfigurationFile::TyToml => None,
-    };
+) -> (String, Cow<'a, str>) {
+    let mut example = Cow::Borrowed(example);
 
-    let header = tool_parent
+    let header = configuration
+        .parent_table()
         .into_iter()
         .chain(parents.iter().filter_map(|parent| parent.name()))
         .chain(scope)
         .join(".");
 
+    // Rewrite examples starting with `[tool.ty]` or `[[tool.ty]]` to their `ty.toml` equivalent.
+    if matches!(configuration, ConfigurationFile::TyToml) {
+        example = example.replace("[tool.ty.", "[").into();
+    }
+
     // Ex) `[[tool.ty.xx]]`
     if example.starts_with(&format!("[[{header}")) {
-        return String::new();
+        return (String::new(), example);
     }
+
     // Ex) `[tool.ty.rules]`
     if example.starts_with(&format!("[{header}")) {
-        return String::new();
+        return (String::new(), example);
     }
 
     if header.is_empty() {
-        String::new()
+        (String::new(), example)
     } else {
-        format!("[{header}]")
+        (format!("[{header}]"), example)
     }
 }
 
@@ -243,10 +252,25 @@ impl Visit for CollectOptionsVisitor {
 #[derive(Debug, Copy, Clone)]
 enum ConfigurationFile {
     PyprojectToml,
-    #[expect(dead_code)]
     TyToml,
 }
 
+impl ConfigurationFile {
+    const fn name(self) -> &'static str {
+        match self {
+            Self::PyprojectToml => "pyproject.toml",
+            Self::TyToml => "ty.toml",
+        }
+    }
+
+    const fn parent_table(self) -> Option<&'static str> {
+        match self {
+            Self::PyprojectToml => Some("tool.ty"),
+            Self::TyToml => None,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use anyhow::Result;

crates/ruff_graph/Cargo.toml

@@ -16,6 +16,7 @@ ruff_linter = { workspace = true }
 ruff_macros = { workspace = true }
 ruff_python_ast = { workspace = true }
 ruff_python_parser = { workspace = true }
+ty_module_resolver = { workspace = true }
 ty_python_semantic = { workspace = true }
 
 anyhow = { workspace = true }

crates/ruff_graph/src/collector.rs

@@ -3,7 +3,7 @@ use ruff_python_ast::visitor::source_order::{
     SourceOrderVisitor, walk_expr, walk_module, walk_stmt,
 };
 use ruff_python_ast::{self as ast, Expr, Mod, Stmt};
-use ty_python_semantic::ModuleName;
+use ty_module_resolver::ModuleName;
 
 /// Collect all imports for a given Python file.
 #[derive(Default, Debug)]

crates/ruff_graph/src/db.rs

@@ -7,10 +7,11 @@ use ruff_db::files::{File, Files};
 use ruff_db::system::{OsSystem, System, SystemPathBuf};
 use ruff_db::vendored::{VendoredFileSystem, VendoredFileSystemBuilder};
 use ruff_python_ast::PythonVersion;
+use ty_module_resolver::{SearchPathSettings, SearchPaths};
 use ty_python_semantic::lint::{LintRegistry, RuleSelection};
 use ty_python_semantic::{
-    Db, Program, ProgramSettings, PythonEnvironment, PythonPlatform, PythonVersionSource,
-    PythonVersionWithSource, SearchPathSettings, SysPrefixPathOrigin, default_lint_registry,
+    AnalysisSettings, Db, Program, ProgramSettings, PythonEnvironment, PythonPlatform,
+    PythonVersionSource, PythonVersionWithSource, SysPrefixPathOrigin, default_lint_registry,
 };
 
 static EMPTY_VENDORED: std::sync::LazyLock<VendoredFileSystem> = std::sync::LazyLock::new(|| {
@@ -26,6 +27,7 @@ pub struct ModuleDb {
     files: Files,
     system: OsSystem,
     rule_selection: Arc<RuleSelection>,
+    analysis_settings: Arc<AnalysisSettings>,
 }
 
 impl ModuleDb {
@@ -85,6 +87,13 @@ impl SourceDb for ModuleDb {
     }
 }
 
+#[salsa::db]
+impl ty_module_resolver::Db for ModuleDb {
+    fn search_paths(&self) -> &SearchPaths {
+        Program::get(self).search_paths(self)
+    }
+}
+
 #[salsa::db]
 impl Db for ModuleDb {
     fn should_check_file(&self, file: File) -> bool {
@@ -102,6 +111,10 @@ impl Db for ModuleDb {
     fn verbose(&self) -> bool {
         false
     }
+
+    fn analysis_settings(&self) -> &AnalysisSettings {
+        &self.analysis_settings
+    }
 }
 
 #[salsa::db]

crates/ruff_graph/src/resolver.rs

@@ -1,6 +1,6 @@
 use ruff_db::files::{File, FilePath, system_path_to_file};
 use ruff_db::system::SystemPath;
-use ty_python_semantic::{
+use ty_module_resolver::{
     ModuleName, resolve_module, resolve_module_confident, resolve_real_module,
     resolve_real_module_confident,
 };

crates/ruff_linter/src/message/grouped.rs

@@ -197,7 +197,7 @@ impl Display for RuleCodeAndBody<'_> {
                         f,
                         "{fix}{body}",
                         fix = format_args!("[{}] ", "*".cyan()),
-                        body = self.message.body(),
+                        body = self.message.concise_message(),
                     );
                 }
             }
@@ -208,14 +208,14 @@ impl Display for RuleCodeAndBody<'_> {
                 f,
                 "{code} {body}",
                 code = code.red().bold(),
-                body = self.message.body(),
+                body = self.message.concise_message(),
             )
         } else {
             write!(
                 f,
                 "{code}: {body}",
                 code = self.message.id().as_str().red().bold(),
-                body = self.message.body(),
+                body = self.message.concise_message(),
             )
         }
     }

crates/ruff_linter/src/message/sarif.rs

@@ -334,7 +334,7 @@ impl<'a> SarifResult<'a> {
             rule_id: RuleCode::from(diagnostic),
             level: "error".to_string(),
             message: SarifMessage {
-                text: diagnostic.body().to_string(),
+                text: diagnostic.concise_message().to_string(),
             },
             fixes: Self::fix(diagnostic, &uri).into_iter().collect(),
             locations: vec![SarifLocation {

crates/ruff_python_parser/resources/inline/err/decorator_missing_expression.py

@@ -3,3 +3,6 @@
 def foo(): ...
 @@
 def foo(): ...
+@test
+@
+class Test

crates/ruff_python_parser/src/parser/expression.rs

@@ -477,6 +477,17 @@ impl<'src> Parser<'src> {
         }
     }
 
+    pub(super) fn parse_missing_name(&mut self) -> ast::ExprName {
+        let identifier = self.parse_missing_identifier();
+
+        ast::ExprName {
+            range: identifier.range,
+            id: identifier.id,
+            ctx: ExprContext::Invalid,
+            node_index: AtomicNodeIndex::NONE,
+        }
+    }
+
     /// Parses an identifier.
     ///
     /// For an invalid identifier, the `id` field will be an empty string.
@@ -524,16 +535,20 @@ impl<'src> Parser<'src> {
                 node_index: AtomicNodeIndex::NONE,
             }
         } else {
-            self.add_error(
-                ParseErrorType::OtherError("Expected an identifier".into()),
-                range,
-            );
+            self.parse_missing_identifier()
+        }
+    }
 
-            ast::Identifier {
-                id: Name::empty(),
-                range: self.missing_node_range(),
-                node_index: AtomicNodeIndex::NONE,
-            }
+    fn parse_missing_identifier(&mut self) -> ast::Identifier {
+        self.add_error(
+            ParseErrorType::OtherError("Expected an identifier".into()),
+            self.current_token_range(),
+        );
+
+        ast::Identifier {
+            id: Name::empty(),
+            range: self.missing_node_range(),
+            node_index: AtomicNodeIndex::NONE,
         }
     }
 

crates/ruff_python_parser/src/parser/statement.rs

@@ -2782,13 +2782,20 @@ impl<'src> Parser<'src> {
         // def foo(): ...
         // @@
         // def foo(): ...
+        // @test
+        // @
+        // class Test
         while self.at(TokenKind::At) {
             progress.assert_progressing(self);
 
             let decorator_start = self.node_start();
             self.bump(TokenKind::At);
 
-            let parsed_expr = self.parse_named_expression_or_higher(ExpressionContext::default());
+            let parsed_expr = if self.at(TokenKind::Def) || self.at(TokenKind::Class) {
+                Expr::Name(self.parse_missing_name()).into()
+            } else {
+                self.parse_named_expression_or_higher(ExpressionContext::default())
+            };
 
             if self.options.target_version < PythonVersion::PY39 {
                 // test_ok decorator_expression_dotted_ident_py38
@@ -2914,21 +2921,27 @@ impl<'src> Parser<'src> {
                     self.current_token_range(),
                 );
 
-                // TODO(dhruvmanila): It seems that this recovery drops all the parsed
-                // decorators. Maybe we could convert them into statement expression
-                // with a flag indicating that this expression is part of a decorator.
-                // It's only possible to keep them if it's a function or class definition.
-                // We could possibly keep them if there's indentation error:
-                //
-                // ```python
-                // @decorator
-                //   @decorator
-                // def foo(): ...
-                // ```
-                //
-                // Or, parse it as a binary expression where the left side is missing.
-                // We would need to convert each decorator into a binary expression.
-                self.parse_statement()
+                let range = self.node_range(start);
+
+                ast::StmtFunctionDef {
+                    node_index: AtomicNodeIndex::default(),
+                    range,
+                    is_async: false,
+                    decorator_list: decorators,
+                    name: ast::Identifier {
+                        id: Name::empty(),
+                        range: self.missing_node_range(),
+                        node_index: AtomicNodeIndex::NONE,
+                    },
+                    type_params: None,
+                    parameters: Box::new(ast::Parameters {
+                        range: self.missing_node_range(),
+                        ..ast::Parameters::default()
+                    }),
+                    returns: None,
+                    body: vec![],
+                }
+                .into()
             }
         }
     }

crates/ruff_python_parser/tests/snapshots/invalid_syntax@decorator_missing_expression.py.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/ruff_python_parser/tests/fixtures.rs
-input_file: crates/ruff_python_parser/resources/inline/err/decorator_missing_expression.py
 ---
 ## AST
 
@@ -8,40 +7,57 @@ input_file: crates/ruff_python_parser/resources/inline/err/decorator_missing_exp
 Module(
     ModModule {
         node_index: NodeIndex(None),
-        range: 0..51,
+        range: 0..70,
         body: [
-            AnnAssign(
-                StmtAnnAssign {
+            FunctionDef(
+                StmtFunctionDef {
                     node_index: NodeIndex(None),
-                    range: 5..15,
-                    target: Call(
-                        ExprCall {
+                    range: 0..15,
+                    is_async: false,
+                    decorator_list: [
+                        Decorator {
+                            range: 0..1,
                             node_index: NodeIndex(None),
-                            range: 5..10,
-                            func: Name(
+                            expression: Name(
                                 ExprName {
                                     node_index: NodeIndex(None),
-                                    range: 5..8,
-                                    id: Name("foo"),
-                                    ctx: Load,
+                                    range: 1..1,
+                                    id: Name(""),
+                                    ctx: Invalid,
                                 },
                             ),
-                            arguments: Arguments {
-                                range: 8..10,
+                        },
+                    ],
+                    name: Identifier {
+                        id: Name("foo"),
+                        range: 5..8,
+                        node_index: NodeIndex(None),
+                    },
+                    type_params: None,
+                    parameters: Parameters {
+                        range: 8..10,
+                        node_index: NodeIndex(None),
+                        posonlyargs: [],
+                        args: [],
+                        vararg: None,
+                        kwonlyargs: [],
+                        kwarg: None,
+                    },
+                    returns: None,
+                    body: [
+                        Expr(
+                            StmtExpr {
                                 node_index: NodeIndex(None),
-                                args: [],
-                                keywords: [],
+                                range: 12..15,
+                                value: EllipsisLiteral(
+                                    ExprEllipsisLiteral {
+                                        node_index: NodeIndex(None),
+                                        range: 12..15,
+                                    },
+                                ),
                             },
-                        },
-                    ),
-                    annotation: EllipsisLiteral(
-                        ExprEllipsisLiteral {
-                            node_index: NodeIndex(None),
-                            range: 12..15,
-                        },
-                    ),
-                    value: None,
-                    simple: false,
+                        ),
+                    ],
                 },
             ),
             FunctionDef(
@@ -161,6 +177,46 @@ Module(
                     ],
                 },
             ),
+            ClassDef(
+                StmtClassDef {
+                    node_index: NodeIndex(None),
+                    range: 51..69,
+                    decorator_list: [
+                        Decorator {
+                            range: 51..56,
+                            node_index: NodeIndex(None),
+                            expression: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 52..56,
+                                    id: Name("test"),
+                                    ctx: Load,
+                                },
+                            ),
+                        },
+                        Decorator {
+                            range: 57..58,
+                            node_index: NodeIndex(None),
+                            expression: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 58..58,
+                                    id: Name(""),
+                                    ctx: Invalid,
+                                },
+                            ),
+                        },
+                    ],
+                    name: Identifier {
+                        id: Name("Test"),
+                        range: 65..69,
+                        node_index: NodeIndex(None),
+                    },
+                    type_params: None,
+                    arguments: None,
+                    body: [],
+                },
+            ),
         ],
     },
 )
@@ -169,15 +225,7 @@ Module(
 
   |
 1 | @def foo(): ...
-  |  ^^^ Syntax Error: Expected an identifier, but found a keyword `def` that cannot be used here
-2 | @
-3 | def foo(): ...
-  |
-
-
-  |
-1 | @def foo(): ...
-  |      ^^^ Syntax Error: Expected newline, found name
+  |  ^^^ Syntax Error: Expected an identifier
 2 | @
 3 | def foo(): ...
   |
@@ -199,6 +247,7 @@ Module(
 4 | @@
   |  ^ Syntax Error: Expected an expression
 5 | def foo(): ...
+6 | @test
   |
 
 
@@ -208,4 +257,23 @@ Module(
 4 | @@
   |   ^ Syntax Error: Expected an expression
 5 | def foo(): ...
+6 | @test
+7 | @
+  |
+
+
+  |
+5 | def foo(): ...
+6 | @test
+7 | @
+  |  ^ Syntax Error: Expected an expression
+8 | class Test
+  |
+
+
+  |
+6 | @test
+7 | @
+8 | class Test
+  |           ^ Syntax Error: Expected `:`, found newline
   |

crates/ruff_python_parser/tests/snapshots/invalid_syntax@decorator_unexpected_token.py.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/ruff_python_parser/tests/fixtures.rs
-input_file: crates/ruff_python_parser/resources/inline/err/decorator_unexpected_token.py
 ---
 ## AST
 
@@ -10,6 +9,44 @@ Module(
         node_index: NodeIndex(None),
         range: 0..34,
         body: [
+            FunctionDef(
+                StmtFunctionDef {
+                    node_index: NodeIndex(None),
+                    range: 0..4,
+                    is_async: false,
+                    decorator_list: [
+                        Decorator {
+                            range: 0..4,
+                            node_index: NodeIndex(None),
+                            expression: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 1..4,
+                                    id: Name("foo"),
+                                    ctx: Load,
+                                },
+                            ),
+                        },
+                    ],
+                    name: Identifier {
+                        id: Name(""),
+                        range: 4..4,
+                        node_index: NodeIndex(None),
+                    },
+                    type_params: None,
+                    parameters: Parameters {
+                        range: 4..4,
+                        node_index: NodeIndex(None),
+                        posonlyargs: [],
+                        args: [],
+                        vararg: None,
+                        kwonlyargs: [],
+                        kwarg: None,
+                    },
+                    returns: None,
+                    body: [],
+                },
+            ),
             With(
                 StmtWith {
                     node_index: NodeIndex(None),
@@ -46,6 +83,44 @@ Module(
                     ],
                 },
             ),
+            FunctionDef(
+                StmtFunctionDef {
+                    node_index: NodeIndex(None),
+                    range: 23..27,
+                    is_async: false,
+                    decorator_list: [
+                        Decorator {
+                            range: 23..27,
+                            node_index: NodeIndex(None),
+                            expression: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 24..27,
+                                    id: Name("foo"),
+                                    ctx: Load,
+                                },
+                            ),
+                        },
+                    ],
+                    name: Identifier {
+                        id: Name(""),
+                        range: 27..27,
+                        node_index: NodeIndex(None),
+                    },
+                    type_params: None,
+                    parameters: Parameters {
+                        range: 27..27,
+                        node_index: NodeIndex(None),
+                        posonlyargs: [],
+                        args: [],
+                        vararg: None,
+                        kwonlyargs: [],
+                        kwarg: None,
+                    },
+                    returns: None,
+                    body: [],
+                },
+            ),
             Assign(
                 StmtAssign {
                     node_index: NodeIndex(None),

crates/ruff_server/src/lint.rs

@@ -243,7 +243,7 @@ fn to_lsp_diagnostic(
 ) -> (usize, lsp_types::Diagnostic) {
     let diagnostic_range = diagnostic.range().unwrap_or_default();
     let name = diagnostic.name();
-    let body = diagnostic.body().to_string();
+    let body = diagnostic.concise_message().to_string();
     let fix = diagnostic.fix();
     let suggestion = diagnostic.first_help_text();
     let code = diagnostic.secondary_code();

crates/ruff_wasm/src/lib.rs

@@ -241,7 +241,7 @@ impl Workspace {
                 let range = msg.range().unwrap_or_default();
                 ExpandedMessage {
                     code: msg.secondary_code_or_id().to_string(),
-                    message: msg.body().to_string(),
+                    message: msg.concise_message().to_string(),
                     start_location: source_code
                         .source_location(range.start(), self.position_encoding)
                         .into(),

crates/ty/Cargo.toml

@@ -42,6 +42,7 @@ wild = { workspace = true }
 [dev-dependencies]
 ruff_db = { workspace = true, features = ["testing"] }
 ruff_python_trivia = { workspace = true }
+ty_module_resolver = { workspace = true }
 
 dunce = { workspace = true }
 insta = { workspace = true, features = ["filters"] }

crates/ty/docs/configuration.md

@@ -20,11 +20,59 @@ Valid severities are:
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.rules]
-possibly-unresolved-reference = "warn"
-division-by-zero = "ignore"
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.rules]
+    possibly-unresolved-reference = "warn"
+    division-by-zero = "ignore"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [rules]
+    possibly-unresolved-reference = "warn"
+    division-by-zero = "ignore"
+    ```
+
+---
+
+## `analysis`
+
+### `respect-type-ignore-comments`
+
+Whether ty should respect `type: ignore` comments.
+
+When set to `false`, `type: ignore` comments are treated like any other normal
+comment and can't be used to suppress ty errors (you have to use `ty: ignore` instead).
+
+Setting this option can be useful when using ty alongside other type checkers or when
+you prefer using `ty: ignore` over `type: ignore`.
+
+Defaults to `true`.
+
+**Default value**: `true`
+
+**Type**: `bool`
+
+**Example usage**:
+
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.analysis]
+    # Disable support for `type: ignore` comments
+    respect-type-ignore-comments = false
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [analysis]
+    # Disable support for `type: ignore` comments
+    respect-type-ignore-comments = false
+    ```
 
 ---
 
@@ -47,10 +95,19 @@ configuration setting.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.environment]
-extra-paths = ["./shared/my-search-path"]
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.environment]
+    extra-paths = ["./shared/my-search-path"]
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [environment]
+    extra-paths = ["./shared/my-search-path"]
+    ```
 
 ---
 
@@ -78,10 +135,19 @@ This option can be used to point to virtual or system Python environments.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.environment]
-python = "./custom-venv-location/.venv"
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.environment]
+    python = "./custom-venv-location/.venv"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [environment]
+    python = "./custom-venv-location/.venv"
+    ```
 
 ---
 
@@ -105,11 +171,21 @@ If no platform is specified, ty will use the current platform:
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.environment]
-# Tailor type stubs and conditionalized type definitions to windows.
-python-platform = "win32"
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.environment]
+    # Tailor type stubs and conditionalized type definitions to windows.
+    python-platform = "win32"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [environment]
+    # Tailor type stubs and conditionalized type definitions to windows.
+    python-platform = "win32"
+    ```
 
 ---
 
@@ -139,10 +215,19 @@ to reflect the differing contents of the standard library across Python versions
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.environment]
-python-version = "3.12"
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.environment]
+    python-version = "3.12"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [environment]
+    python-version = "3.12"
+    ```
 
 ---
 
@@ -167,11 +252,21 @@ it will also be included in the first party search path.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.environment]
-# Multiple directories (priority order)
-root = ["./src", "./lib", "./vendor"]
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.environment]
+    # Multiple directories (priority order)
+    root = ["./src", "./lib", "./vendor"]
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [environment]
+    # Multiple directories (priority order)
+    root = ["./src", "./lib", "./vendor"]
+    ```
 
 ---
 
@@ -187,10 +282,19 @@ bundled as a zip file in the binary
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.environment]
-typeshed = "/path/to/custom/typeshed"
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.environment]
+    typeshed = "/path/to/custom/typeshed"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [environment]
+    typeshed = "/path/to/custom/typeshed"
+    ```
 
 ---
 
@@ -240,15 +344,29 @@ If not specified, defaults to `[]` (excludes no files).
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[[tool.ty.overrides]]
-exclude = [
-    "generated",
-    "*.proto",
-    "tests/fixtures/**",
-    "!tests/fixtures/important.py"  # Include this one file
-]
-```
+=== "pyproject.toml"
+
+    ```toml
+    [[tool.ty.overrides]]
+    exclude = [
+        "generated",
+        "*.proto",
+        "tests/fixtures/**",
+        "!tests/fixtures/important.py"  # Include this one file
+    ]
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [[overrides]]
+    exclude = [
+        "generated",
+        "*.proto",
+        "tests/fixtures/**",
+        "!tests/fixtures/important.py"  # Include this one file
+    ]
+    ```
 
 ---
 
@@ -268,13 +386,25 @@ If not specified, defaults to `["**"]` (matches all files).
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[[tool.ty.overrides]]
-include = [
-    "src",
-    "tests",
-]
-```
+=== "pyproject.toml"
+
+    ```toml
+    [[tool.ty.overrides]]
+    include = [
+        "src",
+        "tests",
+    ]
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [[overrides]]
+    include = [
+        "src",
+        "tests",
+    ]
+    ```
 
 ---
 
@@ -292,13 +422,25 @@ severity levels or disable them entirely.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[[tool.ty.overrides]]
-include = ["src"]
+=== "pyproject.toml"
 
-[tool.ty.overrides.rules]
-possibly-unresolved-reference = "ignore"
-```
+    ```toml
+    [[tool.ty.overrides]]
+    include = ["src"]
+
+    [tool.ty.overrides.rules]
+    possibly-unresolved-reference = "ignore"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [[overrides]]
+    include = ["src"]
+
+    [overrides.rules]
+    possibly-unresolved-reference = "ignore"
+    ```
 
 ---
 
@@ -358,15 +500,29 @@ to re-include `dist` use `exclude = ["!dist"]`
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.src]
-exclude = [
-    "generated",
-    "*.proto",
-    "tests/fixtures/**",
-    "!tests/fixtures/important.py"  # Include this one file
-]
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.src]
+    exclude = [
+        "generated",
+        "*.proto",
+        "tests/fixtures/**",
+        "!tests/fixtures/important.py"  # Include this one file
+    ]
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [src]
+    exclude = [
+        "generated",
+        "*.proto",
+        "tests/fixtures/**",
+        "!tests/fixtures/important.py"  # Include this one file
+    ]
+    ```
 
 ---
 
@@ -399,13 +555,25 @@ matches `<project_root>/src` and not `<project_root>/test/src`).
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.src]
-include = [
-    "src",
-    "tests",
-]
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.src]
+    include = [
+        "src",
+        "tests",
+    ]
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [src]
+    include = [
+        "src",
+        "tests",
+    ]
+    ```
 
 ---
 
@@ -421,10 +589,19 @@ Enabled by default.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.src]
-respect-ignore-files = false
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.src]
+    respect-ignore-files = false
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [src]
+    respect-ignore-files = false
+    ```
 
 ---
 
@@ -450,10 +627,19 @@ it will also be included in the first party search path.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.src]
-root = "./app"
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.src]
+    root = "./app"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [src]
+    root = "./app"
+    ```
 
 ---
 
@@ -471,11 +657,21 @@ Defaults to `false`.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.terminal]
-# Error if ty emits any warning-level diagnostics.
-error-on-warning = true
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.terminal]
+    # Error if ty emits any warning-level diagnostics.
+    error-on-warning = true
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [terminal]
+    # Error if ty emits any warning-level diagnostics.
+    error-on-warning = true
+    ```
 
 ---
 
@@ -491,10 +687,19 @@ Defaults to `full`.
 
 **Example usage**:
 
-```toml title="pyproject.toml"
-[tool.ty.terminal]
-output-format = "concise"
-```
+=== "pyproject.toml"
+
+    ```toml
+    [tool.ty.terminal]
+    output-format = "concise"
+    ```
+
+=== "ty.toml"
+
+    ```toml
+    [terminal]
+    output-format = "concise"
+    ```
 
 ---
 

crates/ty/docs/rules.md

@@ -8,7 +8,7 @@
 Default level: <a href="../../rules#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.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20ambiguous-protocol-member" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L511" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L538" target="_blank">View source</a>
 </small>
 
 
@@ -80,7 +80,7 @@ def test(): -> "int":
 Default level: <a href="../../rules#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%20call-non-callable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L135" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L137" target="_blank">View source</a>
 </small>
 
 
@@ -98,13 +98,44 @@ Calling a non-callable object will raise a `TypeError` at runtime.
 4()  # TypeError: 'int' object is not callable
 ```
 
+## `call-top-callable`
+
+<small>
+Default level: <a href="../../rules#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/0.0.7">0.0.7</a> ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20call-top-callable" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L155" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for calls to objects typed as `Top[Callable[..., T]]` (the infinite union of all
+callable types with return type `T`).
+
+**Why is this bad?**
+
+When an object is narrowed to `Top[Callable[..., object]]` (e.g., via `callable(x)` or
+`isinstance(x, Callable)`), we know the object is callable, but we don't know its
+precise signature. This type represents the set of all possible callable types
+(including, e.g., functions that take no arguments and functions that require arguments),
+so no specific set of arguments can be guaranteed to be valid.
+
+**Examples**
+
+```python
+def f(x: object):
+    if callable(x):
+        x()  # error: We know `x` is callable, but not what arguments it accepts
+```
+
 ## `conflicting-argument-forms`
 
 <small>
 Default level: <a href="../../rules#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%20conflicting-argument-forms" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L179" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L206" target="_blank">View source</a>
 </small>
 
 
@@ -136,7 +167,7 @@ f(int)  # error
 Default level: <a href="../../rules#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%20conflicting-declarations" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L205" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L232" target="_blank">View source</a>
 </small>
 
 
@@ -167,7 +198,7 @@ a = 1
 Default level: <a href="../../rules#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%20conflicting-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L230" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L257" target="_blank">View source</a>
 </small>
 
 
@@ -199,7 +230,7 @@ class C(A, B): ...
 Default level: <a href="../../rules#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%20cyclic-class-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L256" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L283" target="_blank">View source</a>
 </small>
 
 
@@ -231,7 +262,7 @@ class B(A): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-type-alias-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L282" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L309" target="_blank">View source</a>
 </small>
 
 
@@ -259,7 +290,7 @@ type B = A
 Default level: <a href="../../rules#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.16">0.0.1-alpha.16</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20deprecated" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L326" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L353" target="_blank">View source</a>
 </small>
 
 
@@ -286,7 +317,7 @@ old_func()  # emits [deprecated] diagnostic
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Preview (since <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%20division-by-zero" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L304" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L331" target="_blank">View source</a>
 </small>
 
 
@@ -315,7 +346,7 @@ false positives it can produce.
 Default level: <a href="../../rules#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%20duplicate-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L347" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L374" target="_blank">View source</a>
 </small>
 
 
@@ -342,7 +373,7 @@ class B(A, A): ...
 Default level: <a href="../../rules#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.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-kw-only" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L368" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L395" target="_blank">View source</a>
 </small>
 
 
@@ -380,11 +411,24 @@ class A:  # Crash at runtime
 Default level: <a href="../../rules#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%20escape-character-in-forward-annotation" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L120" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L154" target="_blank">View source</a>
 </small>
 
 
-TODO #14889
+**What it does**
+
+Checks for forward annotations that contain escape characters.
+
+**Why is this bad?**
+
+Static analysis tools like ty can't analyze type annotations that contain escape characters.
+
+**Example**
+
+
+```python
+def foo() -> "intt\b": ...
+```
 
 ## `fstring-type-annotation`
 
@@ -423,7 +467,7 @@ def test(): -> "int":
 Default level: <a href="../../rules#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%20ignore-comment-unknown-rule" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L47" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L50" target="_blank">View source</a>
 </small>
 
 
@@ -485,7 +529,7 @@ def test(): -> "Literal[5]":
 Default level: <a href="../../rules#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%20inconsistent-mro" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L594" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L621" target="_blank">View source</a>
 </small>
 
 
@@ -515,7 +559,7 @@ class C(A, B): ...
 Default level: <a href="../../rules#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%20index-out-of-bounds" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L618" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L645" target="_blank">View source</a>
 </small>
 
 
@@ -541,7 +585,7 @@ t[3]  # IndexError: tuple index out of range
 Default level: <a href="../../rules#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.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20instance-layout-conflict" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L400" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L427" target="_blank">View source</a>
 </small>
 
 
@@ -630,7 +674,7 @@ an atypical memory layout.
 Default level: <a href="../../rules#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#L672" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L699" target="_blank">View source</a>
 </small>
 
 
@@ -657,7 +701,7 @@ func("foo")  # error: [invalid-argument-type]
 Default level: <a href="../../rules#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#L712" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L739" target="_blank">View source</a>
 </small>
 
 
@@ -685,7 +729,7 @@ a: int = ''
 Default level: <a href="../../rules#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#L2015" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2042" target="_blank">View source</a>
 </small>
 
 
@@ -719,7 +763,7 @@ C.instance_var = 3  # error: Cannot assign to instance variable
 Default level: <a href="../../rules#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#L734" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L761" target="_blank">View source</a>
 </small>
 
 
@@ -755,7 +799,7 @@ asyncio.run(main())
 Default level: <a href="../../rules#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#L764" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L791" target="_blank">View source</a>
 </small>
 
 
@@ -779,7 +823,7 @@ class A(42): ...  # error: [invalid-base]
 Default level: <a href="../../rules#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#L815" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L842" target="_blank">View source</a>
 </small>
 
 
@@ -806,7 +850,7 @@ with 1:
 Default level: <a href="../../rules#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#L836" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L863" target="_blank">View source</a>
 </small>
 
 
@@ -835,7 +879,7 @@ a: str
 Default level: <a href="../../rules#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#L859" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L886" target="_blank">View source</a>
 </small>
 
 
@@ -879,7 +923,7 @@ except ZeroDivisionError:
 Default level: <a href="../../rules#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.28">0.0.1-alpha.28</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-explicit-override" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1685" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1712" target="_blank">View source</a>
 </small>
 
 
@@ -921,7 +965,7 @@ class D(A):
 Default level: <a href="../../rules#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.35">0.0.1-alpha.35</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-frozen-dataclass-subclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2241" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2268" target="_blank">View source</a>
 </small>
 
 
@@ -965,7 +1009,7 @@ class NonFrozenChild(FrozenBase):  # Error raised here
 Default level: <a href="../../rules#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#L895" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L922" target="_blank">View source</a>
 </small>
 
 
@@ -1003,7 +1047,7 @@ class D(Generic[U, T]): ...
 Default level: <a href="../../rules#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%20invalid-ignore-comment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L72" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L75" target="_blank">View source</a>
 </small>
 
 
@@ -1033,7 +1077,7 @@ a = 20 / 0  # type: ignore
 Default level: <a href="../../rules#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.17">0.0.1-alpha.17</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L639" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L666" target="_blank">View source</a>
 </small>
 
 
@@ -1072,7 +1116,7 @@ carol = Person(name="Carol", age=25)  # typo!
 Default level: <a href="../../rules#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#L926" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L953" target="_blank">View source</a>
 </small>
 
 
@@ -1107,7 +1151,7 @@ def f(t: TypeVar("U")): ...
 Default level: <a href="../../rules#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#L1023" 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>
 
 
@@ -1141,7 +1185,7 @@ class B(metaclass=f): ...
 Default level: <a href="../../rules#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%20invalid-method-override" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2143" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2170" target="_blank">View source</a>
 </small>
 
 
@@ -1248,7 +1292,7 @@ Correct use of `@override` is enforced by ty's `invalid-explicit-override` rule.
 Default level: <a href="../../rules#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-named-tuple" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L546" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L573" target="_blank">View source</a>
 </small>
 
 
@@ -1302,7 +1346,7 @@ AttributeError: Cannot overwrite NamedTuple attribute _asdict
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-newtype" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L999" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1026" target="_blank">View source</a>
 </small>
 
 
@@ -1332,7 +1376,7 @@ Baz = NewType("Baz", int | str)  # error: invalid base for `typing.NewType`
 Default level: <a href="../../rules#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#L1050" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1077" target="_blank">View source</a>
 </small>
 
 
@@ -1382,7 +1426,7 @@ def foo(x: int) -> int: ...
 Default level: <a href="../../rules#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#L1149" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1176" target="_blank">View source</a>
 </small>
 
 
@@ -1408,7 +1452,7 @@ def f(a: int = ''): ...
 Default level: <a href="../../rules#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-paramspec" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L954" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L981" target="_blank">View source</a>
 </small>
 
 
@@ -1439,7 +1483,7 @@ P2 = ParamSpec("S2")  # error: ParamSpec name must match the variable it's assig
 Default level: <a href="../../rules#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-protocol" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L482" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L509" target="_blank">View source</a>
 </small>
 
 
@@ -1473,7 +1517,7 @@ TypeError: Protocols can only inherit from other protocols, got <class 'int'>
 Default level: <a href="../../rules#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#L1169" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1196" target="_blank">View source</a>
 </small>
 
 
@@ -1522,7 +1566,7 @@ def g():
 Default level: <a href="../../rules#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#L693" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L720" target="_blank">View source</a>
 </small>
 
 
@@ -1547,7 +1591,7 @@ def func() -> int:
 Default level: <a href="../../rules#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#L1212" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1239" target="_blank">View source</a>
 </small>
 
 
@@ -1597,7 +1641,45 @@ Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.
 </small>
 
 
-TODO #14889
+**What it does**
+
+Checks for string-literal annotations where the string cannot be
+parsed as a Python expression.
+
+**Why is this bad?**
+
+Type annotations are expected to be Python expressions that
+describe the expected type of a variable, parameter, attribute or
+`return` statement.
+
+Type annotations are permitted to be string-literal expressions, in
+order to enable forward references to names not yet defined.
+However, it must be possible to parse the contents of that string
+literal as a normal Python expression.
+
+**Example**
+
+
+```python
+def foo() -> "intstance of C":
+    return 42
+
+class C: ...
+```
+
+Use instead:
+
+```python
+def foo() -> "C":
+    return 42
+
+class C: ...
+```
+
+**References**
+
+- [Typing spec: The meaning of annotations](https://typing.python.org/en/latest/spec/annotations.html#the-meaning-of-annotations)
+- [Typing spec: String annotations](https://typing.python.org/en/latest/spec/annotations.html#string-annotations)
 
 ## `invalid-type-alias-type`
 
@@ -1605,7 +1687,7 @@ TODO #14889
 Default level: <a href="../../rules#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#L978" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1005" target="_blank">View source</a>
 </small>
 
 
@@ -1632,7 +1714,7 @@ NewAlias = TypeAliasType(get_name(), int)        # error: TypeAliasType name mus
 Default level: <a href="../../rules#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.29">0.0.1-alpha.29</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1444" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1471" target="_blank">View source</a>
 </small>
 
 
@@ -1679,7 +1761,7 @@ Bar[int]  # error: too few arguments
 Default level: <a href="../../rules#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#L1251" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1278" target="_blank">View source</a>
 </small>
 
 
@@ -1709,7 +1791,7 @@ TYPE_CHECKING = ''
 Default level: <a href="../../rules#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#L1275" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1302" target="_blank">View source</a>
 </small>
 
 
@@ -1739,7 +1821,7 @@ b: Annotated[int]  # `Annotated` expects at least two arguments
 Default level: <a href="../../rules#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#L1327" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1354" target="_blank">View source</a>
 </small>
 
 
@@ -1773,7 +1855,7 @@ f(10)  # Error
 Default level: <a href="../../rules#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#L1299" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1326" target="_blank">View source</a>
 </small>
 
 
@@ -1807,7 +1889,7 @@ class C:
 Default level: <a href="../../rules#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#L1355" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1382" target="_blank">View source</a>
 </small>
 
 
@@ -1842,7 +1924,7 @@ T = TypeVar('T', bound=str)  # valid bound TypeVar
 Default level: <a href="../../rules#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#L1384" target="_blank">View source</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>
 </small>
 
 
@@ -1867,7 +1949,7 @@ func()  # TypeError: func() missing 1 required positional argument: 'x'
 Default level: <a href="../../rules#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#L2116" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2143" target="_blank">View source</a>
 </small>
 
 
@@ -1900,7 +1982,7 @@ alice["age"]  # KeyError
 Default level: <a href="../../rules#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#L1403" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1430" target="_blank">View source</a>
 </small>
 
 
@@ -1929,7 +2011,7 @@ func("string")  # error: [no-matching-overload]
 Default level: <a href="../../rules#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#L1426" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1453" target="_blank">View source</a>
 </small>
 
 
@@ -1953,7 +2035,7 @@ Subscripting an object that does not support it will raise a `TypeError` at runt
 Default level: <a href="../../rules#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#L1485" 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>
 
 
@@ -1979,7 +2061,7 @@ for i in 34:  # TypeError: 'int' object is not iterable
 Default level: <a href="../../rules#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.29">0.0.1-alpha.29</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20override-of-final-method" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1658" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1685" target="_blank">View source</a>
 </small>
 
 
@@ -2012,7 +2094,7 @@ class B(A):
 Default level: <a href="../../rules#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#L1536" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1563" target="_blank">View source</a>
 </small>
 
 
@@ -2039,7 +2121,7 @@ f(1, x=2)  # Error raised here
 Default level: <a href="../../rules#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#L1869" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1896" target="_blank">View source</a>
 </small>
 
 
@@ -2066,7 +2148,7 @@ f(x=1)  # Error raised here
 Default level: <a href="../../rules#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#L1557" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1584" target="_blank">View source</a>
 </small>
 
 
@@ -2094,7 +2176,7 @@ A.c  # AttributeError: type object 'A' has no attribute 'c'
 Default level: <a href="../../rules#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-implicit-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L153" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L180" target="_blank">View source</a>
 </small>
 
 
@@ -2126,7 +2208,7 @@ A()[0]  # TypeError: 'A' object is not subscriptable
 Default level: <a href="../../rules#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.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#L1579" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1606" target="_blank">View source</a>
 </small>
 
 
@@ -2163,7 +2245,7 @@ from module import a  # ImportError: cannot import name 'a' from 'module'
 Default level: <a href="../../rules#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#L1609" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1636" target="_blank">View source</a>
 </small>
 
 
@@ -2227,7 +2309,7 @@ def test(): -> "int":
 Default level: <a href="../../rules#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#L2043" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2070" target="_blank">View source</a>
 </small>
 
 
@@ -2254,7 +2336,7 @@ cast(int, f())  # Redundant
 Default level: <a href="../../rules#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#L1991" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2018" target="_blank">View source</a>
 </small>
 
 
@@ -2284,7 +2366,7 @@ static_assert(int(2.0 * 3.0) == 6)  # error: does not have a statically known tr
 Default level: <a href="../../rules#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#L1635" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1662" target="_blank">View source</a>
 </small>
 
 
@@ -2313,7 +2395,7 @@ class B(A): ...  # Error raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.30">0.0.1-alpha.30</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20super-call-in-named-tuple-method" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1803" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1830" target="_blank">View source</a>
 </small>
 
 
@@ -2347,7 +2429,7 @@ class F(NamedTuple):
 Default level: <a href="../../rules#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#L1743" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1770" target="_blank">View source</a>
 </small>
 
 
@@ -2374,7 +2456,7 @@ f("foo")  # Error raised here
 Default level: <a href="../../rules#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#L1721" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1748" target="_blank">View source</a>
 </small>
 
 
@@ -2402,7 +2484,7 @@ def _(x: int):
 Default level: <a href="../../rules#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#L1764" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1791" target="_blank">View source</a>
 </small>
 
 
@@ -2448,7 +2530,7 @@ class A:
 Default level: <a href="../../rules#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#L1830" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1857" target="_blank">View source</a>
 </small>
 
 
@@ -2472,7 +2554,7 @@ reveal_type(1)  # NameError: name 'reveal_type' is not defined
 Default level: <a href="../../rules#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#L1848" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1875" target="_blank">View source</a>
 </small>
 
 
@@ -2499,7 +2581,7 @@ f(x=1, y=2)  # Error raised here
 Default level: <a href="../../rules#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#L1890" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1917" target="_blank">View source</a>
 </small>
 
 
@@ -2527,7 +2609,7 @@ A().foo  # AttributeError: 'A' object has no attribute 'foo'
 Default level: <a href="../../rules#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#L2064" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2091" target="_blank">View source</a>
 </small>
 
 
@@ -2585,7 +2667,7 @@ def g():
 Default level: <a href="../../rules#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#L1912" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1939" target="_blank">View source</a>
 </small>
 
 
@@ -2610,7 +2692,7 @@ import foo  # ModuleNotFoundError: No module named 'foo'
 Default level: <a href="../../rules#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#L1931" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1958" target="_blank">View source</a>
 </small>
 
 
@@ -2635,7 +2717,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../../rules#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#L782" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L809" target="_blank">View source</a>
 </small>
 
 
@@ -2674,7 +2756,7 @@ class D(C): ...  # error: [unsupported-base]
 Default level: <a href="../../rules#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#L1505" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1532" target="_blank">View source</a>
 </small>
 
 
@@ -2711,7 +2793,7 @@ b1 < b2 < b1  # exception raised here
 Default level: <a href="../../rules#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#L1950" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1977" target="_blank">View source</a>
 </small>
 
 
@@ -2739,7 +2821,7 @@ A() + A()  # TypeError: unsupported operand type(s) for +: 'A' and 'A'
 Default level: <a href="../../rules#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%20unused-ignore-comment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L22" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L25" target="_blank">View source</a>
 </small>
 
 
@@ -2770,7 +2852,7 @@ a = 20 / 2
 Default level: <a href="../../rules#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#L1093" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1120" target="_blank">View source</a>
 </small>
 
 
@@ -2833,7 +2915,7 @@ def foo(x: int | str) -> int | str:
 Default level: <a href="../../rules#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#L1972" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1999" target="_blank">View source</a>
 </small>
 
 

crates/ty/src/lib.rs

@@ -10,9 +10,9 @@ use ty_static::EnvVars;
 
 use std::fmt::Write;
 use std::process::{ExitCode, Termination};
+use std::sync::Mutex;
 
 use anyhow::Result;
-use std::sync::Mutex;
 
 use crate::args::{CheckCommand, Command, TerminalColor};
 use crate::logging::{VerbosityLevel, setup_tracing};
@@ -22,6 +22,7 @@ use clap::{CommandFactory, Parser};
 use colored::Colorize;
 use crossbeam::channel as crossbeam_channel;
 use rayon::ThreadPoolBuilder;
+use ruff_db::cancellation::{CancellationToken, CancellationTokenSource};
 use ruff_db::diagnostic::{
     Diagnostic, DiagnosticId, DisplayDiagnosticConfig, DisplayDiagnostics, Severity,
 };
@@ -121,7 +122,9 @@ fn run_check(args: CheckCommand) -> anyhow::Result<ExitStatus> {
     let force_exclude = args.force_exclude();
 
     let mut project_metadata = match &config_file {
-        Some(config_file) => ProjectMetadata::from_config_file(config_file.clone(), &system)?,
+        Some(config_file) => {
+            ProjectMetadata::from_config_file(config_file.clone(), &project_path, &system)?
+        }
         None => ProjectMetadata::discover(&project_path, &system)?,
     };
 
@@ -225,6 +228,11 @@ struct MainLoop {
     printer: Printer,
 
     project_options_overrides: ProjectOptionsOverrides,
+
+    /// Cancellation token that gets set by Ctrl+C.
+    /// Used for long-running operations on the main thread. Operations on background threads
+    /// use Salsa's cancellation mechanism.
+    cancellation_token: CancellationToken,
 }
 
 impl MainLoop {
@@ -234,6 +242,9 @@ impl MainLoop {
     ) -> (Self, MainLoopCancellationToken) {
         let (sender, receiver) = crossbeam_channel::bounded(10);
 
+        let cancellation_token_source = CancellationTokenSource::new();
+        let cancellation_token = cancellation_token_source.token();
+
         (
             Self {
                 sender: sender.clone(),
@@ -241,8 +252,12 @@ impl MainLoop {
                 watcher: None,
                 project_options_overrides,
                 printer,
+                cancellation_token,
+            },
+            MainLoopCancellationToken {
+                sender,
+                source: cancellation_token_source,
             },
-            MainLoopCancellationToken { sender },
         )
     }
 
@@ -314,6 +329,7 @@ impl MainLoop {
                     let display_config = DisplayDiagnosticConfig::default()
                         .format(terminal_settings.output_format.into())
                         .color(colored::control::SHOULD_COLORIZE.should_colorize())
+                        .with_cancellation_token(Some(self.cancellation_token.clone()))
                         .show_fix_diff(true);
 
                     if check_revision == revision {
@@ -357,19 +373,21 @@ impl MainLoop {
                                 )?;
                             }
 
-                            if is_human_readable {
-                                writeln!(
-                                    self.printer.stream_for_failure_summary(),
-                                    "Found {} diagnostic{}",
-                                    diagnostics_count,
-                                    if diagnostics_count > 1 { "s" } else { "" }
-                                )?;
-                            }
+                            if !self.cancellation_token.is_cancelled() {
+                                if is_human_readable {
+                                    writeln!(
+                                        self.printer.stream_for_failure_summary(),
+                                        "Found {} diagnostic{}",
+                                        diagnostics_count,
+                                        if diagnostics_count > 1 { "s" } else { "" }
+                                    )?;
+                                }
 
-                            if exit_status.is_internal_error() {
-                                tracing::warn!(
-                                    "A fatal error occurred while checking some files. Not all project files were analyzed. See the diagnostics list above for details."
-                                );
+                                if exit_status.is_internal_error() {
+                                    tracing::warn!(
+                                        "A fatal error occurred while checking some files. Not all project files were analyzed. See the diagnostics list above for details."
+                                    );
+                                }
                             }
 
                             if self.watcher.is_none() {
@@ -496,10 +514,12 @@ impl ty_project::ProgressReporter for IndicatifReporter {
 #[derive(Debug)]
 struct MainLoopCancellationToken {
     sender: crossbeam_channel::Sender<MainLoopMessage>,
+    source: CancellationTokenSource,
 }
 
 impl MainLoopCancellationToken {
     fn stop(self) {
+        self.source.cancel();
         self.sender.send(MainLoopMessage::Exit).unwrap();
     }
 }

crates/ty/tests/cli/analysis_options.rs

@@ -0,0 +1,43 @@
+use insta_cmd::assert_cmd_snapshot;
+
+use crate::CliTest;
+
+/// ty ignores `type: ignore` comments when setting `respect-type-ignore-comments=false`
+#[test]
+fn respect_type_ignore_comments_is_turned_off() -> anyhow::Result<()> {
+    let case = CliTest::with_file(
+        "test.py",
+        r#"
+            y = a + 5  # type: ignore
+            "#,
+    )?;
+
+    // Assert that there's an `unresolved-reference` diagnostic (error).
+    assert_cmd_snapshot!(case.command(), @r"
+    success: true
+    exit_code: 0
+    ----- stdout -----
+    All checks passed!
+
+    ----- stderr -----
+    ");
+
+    assert_cmd_snapshot!(case.command().arg("--config").arg("analysis.respect-type-ignore-comments=false"), @r"
+    success: false
+    exit_code: 1
+    ----- stdout -----
+    error[unresolved-reference]: Name `a` used when not defined
+     --> test.py:2:5
+      |
+    2 | y = a + 5  # type: ignore
+      |     ^
+      |
+    info: rule `unresolved-reference` is enabled by default
+
+    Found 1 diagnostic
+
+    ----- stderr -----
+    ");
+
+    Ok(())
+}

crates/ty/tests/cli/config_option.rs

@@ -133,7 +133,7 @@ fn cli_config_args_invalid_option() -> anyhow::Result<()> {
       |
     1 | bad-option=true
       | ^^^^^^^^^^
-    unknown field `bad-option`, expected one of `environment`, `src`, `rules`, `terminal`, `overrides`
+    unknown field `bad-option`, expected one of `environment`, `src`, `rules`, `terminal`, `analysis`, `overrides`
 
 
     Usage: ty <COMMAND>

crates/ty/tests/cli/main.rs

@@ -1,3 +1,4 @@
+mod analysis_options;
 mod config_option;
 mod exit_code;
 mod file_selection;
@@ -658,6 +659,8 @@ fn gitlab_diagnostics() -> anyhow::Result<()> {
         r#"
         print(x)     # [unresolved-reference]
         print(4[1])  # [non-subscriptable]
+        from typing_extensions import reveal_type
+        reveal_type('str'.lower())  # [revealed-type]
         "#,
     )?;
 
@@ -708,6 +711,25 @@ fn gitlab_diagnostics() -> anyhow::Result<()> {
             }
           }
         }
+      },
+      {
+        "check_name": "revealed-type",
+        "description": "revealed-type: Revealed type: `LiteralString`",
+        "severity": "info",
+        "fingerprint": "[FINGERPRINT]",
+        "location": {
+          "path": "test.py",
+          "positions": {
+            "begin": {
+              "line": 5,
+              "column": 13
+            },
+            "end": {
+              "line": 5,
+              "column": 26
+            }
+          }
+        }
       }
     ]
     ----- stderr -----
@@ -723,6 +745,8 @@ fn github_diagnostics() -> anyhow::Result<()> {
         r#"
         print(x)     # [unresolved-reference]
         print(4[1])  # [non-subscriptable]
+        from typing_extensions import reveal_type
+        reveal_type('str'.lower())  # [revealed-type]
         "#,
     )?;
 
@@ -732,6 +756,7 @@ fn github_diagnostics() -> anyhow::Result<()> {
     ----- stdout -----
     ::warning title=ty (unresolved-reference),file=<temp_dir>/test.py,line=2,col=7,endLine=2,endColumn=8::test.py:2:7: unresolved-reference: Name `x` used when not defined
     ::error title=ty (non-subscriptable),file=<temp_dir>/test.py,line=3,col=7,endLine=3,endColumn=11::test.py:3:7: non-subscriptable: Cannot subscript object of type `Literal[4]` with no `__getitem__` method
+    ::notice title=ty (revealed-type),file=<temp_dir>/test.py,line=5,col=13,endLine=5,endColumn=26::test.py:5:13: revealed-type: Revealed type: `LiteralString`
 
     ----- stderr -----
     ");

crates/ty/tests/file_watching.rs

@@ -10,12 +10,13 @@ use ruff_db::system::{
     OsSystem, System, SystemPath, SystemPathBuf, UserConfigDirectoryOverrideGuard, file_time_now,
 };
 use ruff_python_ast::PythonVersion;
+use ty_module_resolver::{Module, ModuleName, resolve_module_confident};
 use ty_project::metadata::options::{EnvironmentOptions, Options, ProjectOptionsOverrides};
 use ty_project::metadata::pyproject::{PyProject, Tool};
 use ty_project::metadata::value::{RangedValue, RelativePathBuf};
 use ty_project::watch::{ChangeEvent, ProjectWatcher, directory_watcher};
 use ty_project::{Db, ProjectDatabase, ProjectMetadata};
-use ty_python_semantic::{Module, ModuleName, PythonPlatform, resolve_module_confident};
+use ty_python_semantic::PythonPlatform;
 
 struct TestCase {
     db: ProjectDatabase,
@@ -1019,7 +1020,7 @@ fn search_path() -> anyhow::Result<()> {
     let site_packages = case.root_path().join("site_packages");
 
     assert_eq!(
-        resolve_module_confident(case.db(), &ModuleName::new("a").unwrap()),
+        resolve_module_confident(case.db(), &ModuleName::new_static("a").unwrap()),
         None
     );
 
@@ -1192,7 +1193,7 @@ fn changed_versions_file() -> anyhow::Result<()> {
 
     // Unset the custom typeshed directory.
     assert_eq!(
-        resolve_module_confident(case.db(), &ModuleName::new("os").unwrap()),
+        resolve_module_confident(case.db(), &ModuleName::new_static("os").unwrap()),
         None
     );
 
@@ -1207,7 +1208,7 @@ fn changed_versions_file() -> anyhow::Result<()> {
 
     case.apply_changes(changes, None);
 
-    assert!(resolve_module_confident(case.db(), &ModuleName::new("os").unwrap()).is_some());
+    assert!(resolve_module_confident(case.db(), &ModuleName::new_static("os").unwrap()).is_some());
 
     Ok(())
 }
@@ -1874,11 +1875,11 @@ fn rename_files_casing_only() -> anyhow::Result<()> {
     let mut case = setup([("lib.py", "class Foo: ...")])?;
 
     assert!(
-        resolve_module_confident(case.db(), &ModuleName::new("lib").unwrap()).is_some(),
+        resolve_module_confident(case.db(), &ModuleName::new_static("lib").unwrap()).is_some(),
         "Expected `lib` module to exist."
     );
     assert_eq!(
-        resolve_module_confident(case.db(), &ModuleName::new("Lib").unwrap()),
+        resolve_module_confident(case.db(), &ModuleName::new_static("Lib").unwrap()),
         None,
         "Expected `Lib` module not to exist"
     );
@@ -1911,13 +1912,13 @@ fn rename_files_casing_only() -> anyhow::Result<()> {
 
     // Resolving `lib` should now fail but `Lib` should now succeed
     assert_eq!(
-        resolve_module_confident(case.db(), &ModuleName::new("lib").unwrap()),
+        resolve_module_confident(case.db(), &ModuleName::new_static("lib").unwrap()),
         None,
         "Expected `lib` module to no longer exist."
     );
 
     assert!(
-        resolve_module_confident(case.db(), &ModuleName::new("Lib").unwrap()).is_some(),
+        resolve_module_confident(case.db(), &ModuleName::new_static("Lib").unwrap()).is_some(),
         "Expected `Lib` module to exist"
     );
 

crates/ty_combine/Cargo.toml

@@ -12,7 +12,6 @@ license.workspace = true
 [dependencies]
 ruff_db = { workspace = true }
 ruff_python_ast = { workspace = true }
-ty_python_semantic = { workspace = true }
 
 ordermap = { workspace = true }
 

crates/ty_combine/src/lib.rs

@@ -8,7 +8,6 @@ use std::{collections::HashMap, hash::BuildHasher};
 use ordermap::OrderMap;
 use ruff_db::system::SystemPathBuf;
 use ruff_python_ast::PythonVersion;
-use ty_python_semantic::PythonPlatform;
 
 /// Combine two values, preferring the values in `self`.
 ///
@@ -145,7 +144,6 @@ macro_rules! impl_noop_combine {
 }
 
 impl_noop_combine!(SystemPathBuf);
-impl_noop_combine!(PythonPlatform);
 impl_noop_combine!(PythonVersion);
 
 // std types

crates/ty_completion_eval/Cargo.toml

@@ -15,8 +15,8 @@ ruff_db = { workspace = true, features = ["os"] }
 ruff_text_size = { workspace = true }
 
 ty_ide = { workspace = true }
+ty_module_resolver = { workspace = true }
 ty_project = { workspace = true }
-ty_python_semantic = { workspace = true }
 
 anyhow = { workspace = true }
 bstr = { workspace = true }

crates/ty_completion_eval/src/main.rs

@@ -15,11 +15,11 @@ use regex::bytes::Regex;
 use ruff_db::files::system_path_to_file;
 use ruff_db::system::{OsSystem, SystemPath, SystemPathBuf};
 use ty_ide::Completion;
+use ty_module_resolver::ModuleName;
 use ty_project::metadata::Options;
 use ty_project::metadata::options::EnvironmentOptions;
 use ty_project::metadata::value::RelativePathBuf;
 use ty_project::{ProjectDatabase, ProjectMetadata};
-use ty_python_semantic::ModuleName;
 
 #[derive(Debug, clap::Parser)]
 #[command(

crates/ty_ide/Cargo.toml

@@ -22,6 +22,7 @@ ruff_python_importer = { workspace = true }
 ruff_python_trivia = { workspace = true }
 ruff_source_file = { workspace = true }
 ruff_text_size = { workspace = true }
+ty_module_resolver = { workspace = true }
 ty_python_semantic = { workspace = true }
 ty_project = { workspace = true, features = ["testing"] }
 ty_vendored = { workspace = true }

crates/ty_ide/src/all_symbols.rs

@@ -1,6 +1,6 @@
 use ruff_db::files::File;
+use ty_module_resolver::{Module, ModuleName, all_modules, resolve_real_shadowable_module};
 use ty_project::Db;
-use ty_python_semantic::{Module, ModuleName, all_modules, resolve_real_shadowable_module};
 
 use crate::{
     SymbolKind,
@@ -21,7 +21,7 @@ pub fn all_symbols<'db>(
         return Vec::new();
     }
 
-    let typing_extensions = ModuleName::new("typing_extensions").unwrap();
+    let typing_extensions = ModuleName::new_static("typing_extensions").unwrap();
     let is_typing_extensions_available = importing_from.is_stub(db)
         || resolve_real_shadowable_module(db, importing_from, &typing_extensions).is_some();
 

crates/ty_ide/src/completion.rs

@@ -11,9 +11,10 @@ use ruff_python_ast::{self as ast, AnyNodeRef};
 use ruff_python_codegen::Stylist;
 use ruff_text_size::{Ranged, TextRange, TextSize};
 use rustc_hash::FxHashSet;
+use ty_module_resolver::{KnownModule, ModuleName};
 use ty_python_semantic::types::UnionType;
 use ty_python_semantic::{
-    Completion as SemanticCompletion, KnownModule, ModuleName, NameKind, SemanticModel,
+    Completion as SemanticCompletion, NameKind, SemanticModel,
     types::{CycleDetector, KnownClass, Type},
 };
 
@@ -2106,7 +2107,7 @@ mod tests {
     use insta::assert_snapshot;
     use ruff_python_ast::token::{TokenKind, Tokens};
     use ruff_python_parser::{Mode, ParseOptions};
-    use ty_python_semantic::ModuleName;
+    use ty_module_resolver::ModuleName;
 
     use crate::completion::{Completion, completion};
     use crate::tests::{CursorTest, CursorTestBuilder};
@@ -6685,6 +6686,19 @@ def func():
         .not_contains("False");
     }
 
+    #[test]
+    fn decorator_without_class_or_function() {
+        completion_test_builder(
+            "\
+from dataclasses import dataclass
+
+@dataclass(froz<CURSOR>
+",
+        )
+        .build()
+        .contains("frozen");
+    }
+
     #[test]
     fn statement_keywords_in_if_body() {
         completion_test_builder(

crates/ty_ide/src/importer.rs

@@ -29,10 +29,11 @@ use ruff_python_ast::visitor::source_order::{SourceOrderVisitor, TraversalSignal
 use ruff_python_codegen::Stylist;
 use ruff_python_importer::Insertion;
 use ruff_text_size::{Ranged, TextRange, TextSize};
+use ty_module_resolver::ModuleName;
 use ty_project::Db;
 use ty_python_semantic::semantic_index::definition::DefinitionKind;
 use ty_python_semantic::types::Type;
-use ty_python_semantic::{MemberDefinition, ModuleName, SemanticModel};
+use ty_python_semantic::{MemberDefinition, SemanticModel};
 
 pub(crate) struct Importer<'a> {
     /// The ty Salsa database.
@@ -880,10 +881,10 @@ mod tests {
     use ruff_python_codegen::Stylist;
     use ruff_python_trivia::textwrap::dedent;
     use ruff_text_size::TextSize;
+    use ty_module_resolver::SearchPathSettings;
     use ty_project::ProjectMetadata;
     use ty_python_semantic::{
-        Program, ProgramSettings, PythonPlatform, PythonVersionWithSource, SearchPathSettings,
-        SemanticModel,
+        Program, ProgramSettings, PythonPlatform, PythonVersionWithSource, SemanticModel,
     };
 
     use super::*;

crates/ty_ide/src/inlay_hints.rs

@@ -6614,13 +6614,6 @@ mod tests {
         3 |     y[: type[T@f]] = x
           |              ^^^
           |
-
-        ---------------------------------------------
-        info[inlay-hint-edit]: File after edits
-        info: Source
-
-        def f[T](x: type[T]):
-            y: type[T@f] = x
         "#);
     }
 

crates/ty_ide/src/semantic_tokens.rs

@@ -17,9 +17,6 @@
 //! TODO: Need to properly handle Annotated expressions. All type arguments other
 //! than the first should be treated as value expressions, not as type expressions.
 //!
-//! TODO: An identifier that resolves to a parameter when used within a function
-//! should be classified as a parameter, selfParameter, or clsParameter token.
-//!
 //! TODO: Properties (or perhaps more generally, descriptor objects?) should be
 //! classified as property tokens rather than just variables.
 //!
@@ -230,6 +227,11 @@ impl<'db> SemanticTokenVisitor<'db> {
         modifiers: SemanticTokenModifier,
     ) {
         let range = ranged.range();
+
+        if range.is_empty() {
+            return;
+        }
+
         // Only emit tokens that intersect with the range filter, if one is specified
         if let Some(range_filter) = self.range_filter {
             // Only include ranges that have a non-empty overlap. Adjacent ranges
@@ -707,15 +709,15 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
             }
             ast::Stmt::Import(import) => {
                 for alias in &import.names {
+                    // Create separate tokens for each part of a dotted module name
+                    self.add_dotted_name_tokens(&alias.name, SemanticTokenType::Namespace);
+
                     if let Some(asname) = &alias.asname {
                         self.add_token(
                             asname.range(),
                             SemanticTokenType::Namespace,
                             SemanticTokenModifier::empty(),
                         );
-                    } else {
-                        // Create separate tokens for each part of a dotted module name
-                        self.add_dotted_name_tokens(&alias.name, SemanticTokenType::Namespace);
                     }
                 }
             }
@@ -1131,7 +1133,7 @@ mod tests {
     use ty_project::ProjectMetadata;
 
     #[test]
-    fn test_semantic_tokens_basic() {
+    fn semantic_tokens_basic() {
         let test = SemanticTokenTest::new("def foo(): pass");
 
         let tokens = test.highlight_file();
@@ -1142,7 +1144,7 @@ mod tests {
     }
 
     #[test]
-    fn test_semantic_tokens_class() {
+    fn semantic_tokens_class() {
         let test = SemanticTokenTest::new("class MyClass: pass");
 
         let tokens = test.highlight_file();
@@ -1153,7 +1155,7 @@ mod tests {
     }
 
     #[test]
-    fn test_semantic_tokens_class_args() {
+    fn semantic_tokens_class_args() {
         // This used to cause a panic because of an incorrect
         // insertion-order when visiting arguments inside
         // class definitions.
@@ -1169,7 +1171,7 @@ mod tests {
     }
 
     #[test]
-    fn test_semantic_tokens_variables() {
+    fn semantic_tokens_variables() {
         let test = SemanticTokenTest::new(
             "
 x = 42
@@ -1188,7 +1190,7 @@ y = 'hello'
     }
 
     #[test]
-    fn test_semantic_tokens_walrus() {
+    fn semantic_tokens_walrus() {
         let test = SemanticTokenTest::new(
             "
 if x := 42:
@@ -1207,7 +1209,7 @@ if x := 42:
     }
 
     #[test]
-    fn test_semantic_tokens_self_parameter() {
+    fn semantic_tokens_self_parameter() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -1238,7 +1240,7 @@ class MyClass:
     }
 
     #[test]
-    fn test_semantic_tokens_cls_parameter() {
+    fn semantic_tokens_cls_parameter() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -1261,7 +1263,7 @@ class MyClass:
     }
 
     #[test]
-    fn test_semantic_tokens_staticmethod_parameter() {
+    fn semantic_tokens_staticmethod_parameter() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -1282,7 +1284,7 @@ class MyClass:
     }
 
     #[test]
-    fn test_semantic_tokens_custom_self_cls_names() {
+    fn semantic_tokens_custom_self_cls_names() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -1317,7 +1319,7 @@ class MyClass:
     }
 
     #[test]
-    fn test_semantic_tokens_modifiers() {
+    fn semantic_tokens_modifiers() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -1338,7 +1340,7 @@ class MyClass:
     }
 
     #[test]
-    fn test_semantic_classification_vs_heuristic() {
+    fn semantic_classification_vs_heuristic() {
         let test = SemanticTokenTest::new(
             "
 import sys
@@ -1372,7 +1374,7 @@ z = sys.version
     }
 
     #[test]
-    fn test_builtin_constants() {
+    fn builtin_constants() {
         let test = SemanticTokenTest::new(
             "
 x = True
@@ -1394,7 +1396,7 @@ z = None
     }
 
     #[test]
-    fn test_builtin_constants_in_expressions() {
+    fn builtin_constants_in_expressions() {
         let test = SemanticTokenTest::new(
             "
 def check(value):
@@ -1422,7 +1424,7 @@ result = check(None)
     }
 
     #[test]
-    fn test_builtin_types() {
+    fn builtin_types() {
         let test = SemanticTokenTest::new(
             r#"
             type U = str | int
@@ -1467,7 +1469,7 @@ result = check(None)
     }
 
     #[test]
-    fn test_semantic_tokens_range() {
+    fn semantic_tokens_range() {
         let test = SemanticTokenTest::new(
             "
 def function1():
@@ -1532,7 +1534,7 @@ def function2():
     /// When a token starts right at where the requested range ends,
     /// don't include it in the semantic tokens.
     #[test]
-    fn test_semantic_tokens_range_excludes_boundary_tokens() {
+    fn semantic_tokens_range_excludes_boundary_tokens() {
         let test = SemanticTokenTest::new(
             "
 x = 1
@@ -1555,7 +1557,7 @@ z = 3
     }
 
     #[test]
-    fn test_dotted_module_names() {
+    fn dotted_module_names() {
         let test = SemanticTokenTest::new(
             "
 import os.path
@@ -1582,7 +1584,7 @@ from collections.abc import Mapping
     }
 
     #[test]
-    fn test_module_type_classification() {
+    fn module_type_classification() {
         let test = SemanticTokenTest::new(
             "
 import os
@@ -1610,7 +1612,7 @@ y = sys
     }
 
     #[test]
-    fn test_import_classification() {
+    fn import_classification() {
         let test = SemanticTokenTest::new(
             "
 from os import path
@@ -1641,7 +1643,7 @@ from mymodule import CONSTANT, my_function, MyClass
     }
 
     #[test]
-    fn test_str_annotation() {
+    fn str_annotation() {
         let test = SemanticTokenTest::new(
             r#"
 x: int = 1
@@ -1685,7 +1687,7 @@ w5: "float
     }
 
     #[test]
-    fn test_attribute_classification() {
+    fn attribute_classification() {
         let test = SemanticTokenTest::new(
             "
 import os
@@ -1759,7 +1761,7 @@ u = List.__name__        # __name__ should be variable
     }
 
     #[test]
-    fn test_attribute_fallback_classification() {
+    fn attribute_fallback_classification() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -1790,7 +1792,7 @@ y = obj.unknown_attr     # Should fall back to variable
     }
 
     #[test]
-    fn test_constant_name_detection() {
+    fn constant_name_detection() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -1837,7 +1839,7 @@ w = obj.A             # Should not have readonly modifier (length == 1)
     }
 
     #[test]
-    fn test_type_annotations() {
+    fn type_annotations() {
         let test = SemanticTokenTest::new(
             r#"
 from typing import List, Optional
@@ -2325,7 +2327,7 @@ class MyClass:
     }
 
     #[test]
-    fn test_debug_int_classification() {
+    fn debug_int_classification() {
         let test = SemanticTokenTest::new(
             "
 x: int = 42
@@ -2342,7 +2344,7 @@ x: int = 42
     }
 
     #[test]
-    fn test_debug_user_defined_type_classification() {
+    fn debug_user_defined_type_classification() {
         let test = SemanticTokenTest::new(
             "
 class MyClass:
@@ -2363,7 +2365,7 @@ x: MyClass = MyClass()
     }
 
     #[test]
-    fn test_type_annotation_vs_variable_classification() {
+    fn type_annotation_vs_variable_classification() {
         let test = SemanticTokenTest::new(
             "
 from typing import List, Optional
@@ -2413,7 +2415,7 @@ def test_function(param: int, other: MyClass) -> Optional[List[str]]:
     }
 
     #[test]
-    fn test_protocol_types_in_annotations() {
+    fn protocol_types_in_annotations() {
         let test = SemanticTokenTest::new(
             "
 from typing import Protocol
@@ -2444,7 +2446,7 @@ def test_function(param: MyProtocol) -> None:
     }
 
     #[test]
-    fn test_protocol_type_annotation_vs_value_context() {
+    fn protocol_type_annotation_vs_value_context() {
         let test = SemanticTokenTest::new(
             "
 from typing import Protocol
@@ -2530,7 +2532,7 @@ def test_function(param: my_type_alias): ...
     }
 
     #[test]
-    fn test_type_parameters_pep695() {
+    fn type_parameters_pep695() {
         let test = SemanticTokenTest::new(
             "
 # Test Python 3.12 PEP 695 type parameter syntax
@@ -2654,7 +2656,7 @@ class BoundedContainer[T: int, U = str]:
     }
 
     #[test]
-    fn test_type_parameters_usage_in_function_body() {
+    fn type_parameters_usage_in_function_body() {
         let test = SemanticTokenTest::new(
             "
 def generic_function[T](value: T) -> T:
@@ -2683,7 +2685,7 @@ def generic_function[T](value: T) -> T:
     }
 
     #[test]
-    fn test_decorator_classification() {
+    fn decorator_classification() {
         let test = SemanticTokenTest::new(
             r#"
 @staticmethod
@@ -2713,7 +2715,7 @@ class MyClass:
     }
 
     #[test]
-    fn test_constant_variations() {
+    fn constant_variations() {
         let test = SemanticTokenTest::new(
             r#"
 A = 1
@@ -2756,7 +2758,7 @@ A_1 = 1
     }
 
     #[test]
-    fn test_implicitly_concatenated_strings() {
+    fn implicitly_concatenated_strings() {
         let test = SemanticTokenTest::new(
             r#"x = "hello" "world"
 y = ("multi"
@@ -2783,7 +2785,7 @@ z = 'single' "mixed" 'quotes'"#,
     }
 
     #[test]
-    fn test_bytes_literals() {
+    fn bytes_literals() {
         let test = SemanticTokenTest::new(
             r#"x = b"hello" b"world"
 y = (b"multi"
@@ -2810,7 +2812,7 @@ z = b'single' b"mixed" b'quotes'"#,
     }
 
     #[test]
-    fn test_mixed_string_and_bytes_literals() {
+    fn mixed_string_and_bytes_literals() {
         let test = SemanticTokenTest::new(
             r#"# Test mixed string and bytes literals
 string_concat = "hello" "world"
@@ -2846,7 +2848,7 @@ regular_bytes = b"just bytes""#,
     }
 
     #[test]
-    fn test_fstring_with_mixed_literals() {
+    fn fstring_with_mixed_literals() {
         let test = SemanticTokenTest::new(
             r#"
 # Test f-strings with various literal types
@@ -2898,7 +2900,7 @@ complex_fstring = f"User: {name.upper()}, Count: {len(data)}, Hex: {value:x}"
     }
 
     #[test]
-    fn test_nonlocal_and_global_statements() {
+    fn nonlocal_and_global_statements() {
         let test = SemanticTokenTest::new(
             r#"
 x = "global_value"
@@ -2960,7 +2962,7 @@ def outer():
     }
 
     #[test]
-    fn test_nonlocal_global_edge_cases() {
+    fn nonlocal_global_edge_cases() {
         let test = SemanticTokenTest::new(
             r#"
 # Single variable statements
@@ -3000,7 +3002,7 @@ def test():
     }
 
     #[test]
-    fn test_pattern_matching() {
+    fn pattern_matching() {
         let test = SemanticTokenTest::new(
             r#"
 def process_data(data):
@@ -3056,7 +3058,7 @@ def process_data(data):
     }
 
     #[test]
-    fn test_exception_handlers() {
+    fn exception_handlers() {
         let test = SemanticTokenTest::new(
             r#"
 try:
@@ -3095,7 +3097,7 @@ finally:
     }
 
     #[test]
-    fn test_self_attribute_expression() {
+    fn self_attribute_expression() {
         let test = SemanticTokenTest::new(
             r#"
 from typing import Self
@@ -3135,7 +3137,7 @@ class C:
     }
 
     #[test]
-    fn test_augmented_assignment() {
+    fn augmented_assignment() {
         let test = SemanticTokenTest::new(
             r#"
 x = 0
@@ -3154,7 +3156,7 @@ x += 1
     }
 
     #[test]
-    fn test_type_alias() {
+    fn type_alias() {
         let test = SemanticTokenTest::new("type MyList[T] = list[T]");
 
         let tokens = test.highlight_file();
@@ -3168,7 +3170,7 @@ x += 1
     }
 
     #[test]
-    fn test_for_stmt() {
+    fn for_stmt() {
         let test = SemanticTokenTest::new(
             r#"
 for item in []:
@@ -3190,7 +3192,7 @@ else:
     }
 
     #[test]
-    fn test_with_stmt() {
+    fn with_stmt() {
         let test = SemanticTokenTest::new(
             r#"
 with open("file.txt") as f:
@@ -3210,7 +3212,7 @@ with open("file.txt") as f:
     }
 
     #[test]
-    fn test_comprehensions() {
+    fn comprehensions() {
         let test = SemanticTokenTest::new(
             r#"
 list_comp = [x for x in range(10) if x % 2 == 0]
@@ -3255,7 +3257,7 @@ generator = (x for x in range(10))
 
     /// Regression test for <https://github.com/astral-sh/ty/issues/1406>
     #[test]
-    fn test_invalid_kwargs() {
+    fn invalid_kwargs() {
         let test = SemanticTokenTest::new(
             r#"
 def foo(self, **key, value=10):
@@ -3274,6 +3276,24 @@ def foo(self, **key, value=10):
         "#);
     }
 
+    #[test]
+    fn import_as() {
+        let test = SemanticTokenTest::new(
+            r#"
+            import pathlib as path
+            from pathlib import Path
+            "#,
+        );
+
+        let tokens = test.highlight_file();
+        assert_snapshot!(test.to_snapshot(&tokens), @r#"
+        "pathlib" @ 8..15: Namespace
+        "path" @ 19..23: Namespace
+        "pathlib" @ 29..36: Namespace
+        "Path" @ 44..48: Class
+        "#);
+    }
+
     pub(super) struct SemanticTokenTest {
         pub(super) db: ty_project::TestDb,
         file: File,

crates/ty_ide/src/symbols.rs

@@ -14,8 +14,8 @@ use ruff_python_ast::name::{Name, UnqualifiedName};
 use ruff_python_ast::visitor::source_order::{self, SourceOrderVisitor};
 use ruff_text_size::{Ranged, TextRange};
 use rustc_hash::{FxHashMap, FxHashSet};
+use ty_module_resolver::{ModuleName, resolve_module};
 use ty_project::Db;
-use ty_python_semantic::{ModuleName, resolve_module};
 
 use crate::completion::CompletionKind;
 

crates/ty_module_resolver/Cargo.toml

@@ -0,0 +1,38 @@
+[package]
+name = "ty_module_resolver"
+version = "0.0.0"
+publish = false
+authors = { workspace = true }
+edition = { workspace = true }
+rust-version = { workspace = true }
+homepage = { workspace = true }
+documentation = { workspace = true }
+repository = { workspace = true }
+license = { workspace = true }
+
+[dependencies]
+ruff_db = { workspace = true }
+ruff_memory_usage = { workspace = true }
+ruff_python_ast = { workspace = true, features = ["salsa"] }
+ruff_python_stdlib = { workspace = true }
+
+camino = { workspace = true }
+compact_str = { workspace = true }
+get-size2 = { workspace = true }
+rustc-hash = { workspace = true }
+salsa = { workspace = true }
+thiserror = { workspace = true }
+tracing = { workspace = true }
+strum = { workspace = true }
+strum_macros = { workspace = true }
+
+[dev-dependencies]
+ruff_db = { workspace = true, features = ["testing", "os"] }
+ty_vendored = { workspace = true }
+
+anyhow = { workspace = true }
+insta = { workspace = true, features = ["filters"] }
+tempfile = { workspace = true }
+
+[lints]
+workspace = true

crates/ty_module_resolver/src/db.rs

@@ -0,0 +1,124 @@
+use ruff_db::Db as SourceDb;
+
+use crate::resolve::SearchPaths;
+
+#[salsa::db]
+pub trait Db: SourceDb {
+    /// Returns the search paths for module resolution.
+    fn search_paths(&self) -> &SearchPaths;
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use std::sync::{Arc, Mutex};
+
+    use ruff_db::Db as SourceDb;
+    use ruff_db::files::Files;
+    use ruff_db::system::{DbWithTestSystem, TestSystem};
+    use ruff_db::vendored::VendoredFileSystem;
+    use ruff_python_ast::PythonVersion;
+
+    use super::Db;
+    use crate::resolve::SearchPaths;
+
+    type Events = Arc<Mutex<Vec<salsa::Event>>>;
+
+    #[salsa::db]
+    #[derive(Clone)]
+    pub(crate) struct TestDb {
+        storage: salsa::Storage<Self>,
+        files: Files,
+        system: TestSystem,
+        vendored: VendoredFileSystem,
+        search_paths: Arc<SearchPaths>,
+        python_version: PythonVersion,
+        events: Events,
+    }
+
+    impl TestDb {
+        pub(crate) fn new() -> Self {
+            let events = Events::default();
+            Self {
+                storage: salsa::Storage::new(Some(Box::new({
+                    let events = events.clone();
+                    move |event| {
+                        tracing::trace!("event: {event:?}");
+                        let mut events = events.lock().unwrap();
+                        events.push(event);
+                    }
+                }))),
+                system: TestSystem::default(),
+                vendored: ty_vendored::file_system().clone(),
+                files: Files::default(),
+                search_paths: Arc::new(SearchPaths::empty(ty_vendored::file_system())),
+                python_version: PythonVersion::default(),
+                events,
+            }
+        }
+
+        pub(crate) fn with_search_paths(mut self, search_paths: SearchPaths) -> Self {
+            self.set_search_paths(search_paths);
+            self
+        }
+
+        pub(crate) fn with_python_version(mut self, python_version: PythonVersion) -> Self {
+            self.python_version = python_version;
+            self
+        }
+
+        pub(crate) fn set_search_paths(&mut self, search_paths: SearchPaths) {
+            search_paths.try_register_static_roots(self);
+            self.search_paths = Arc::new(search_paths);
+        }
+
+        /// Takes the salsa events.
+        pub(crate) fn take_salsa_events(&mut self) -> Vec<salsa::Event> {
+            let mut events = self.events.lock().unwrap();
+            std::mem::take(&mut *events)
+        }
+
+        /// Clears the salsa events.
+        pub(crate) fn clear_salsa_events(&mut self) {
+            self.take_salsa_events();
+        }
+    }
+
+    impl DbWithTestSystem for TestDb {
+        fn test_system(&self) -> &TestSystem {
+            &self.system
+        }
+
+        fn test_system_mut(&mut self) -> &mut TestSystem {
+            &mut self.system
+        }
+    }
+
+    #[salsa::db]
+    impl SourceDb for TestDb {
+        fn vendored(&self) -> &VendoredFileSystem {
+            &self.vendored
+        }
+
+        fn system(&self) -> &dyn ruff_db::system::System {
+            &self.system
+        }
+
+        fn files(&self) -> &Files {
+            &self.files
+        }
+
+        fn python_version(&self) -> PythonVersion {
+            self.python_version
+        }
+    }
+
+    #[salsa::db]
+    impl Db for TestDb {
+        fn search_paths(&self) -> &SearchPaths {
+            &self.search_paths
+        }
+    }
+
+    #[salsa::db]
+    impl salsa::Database for TestDb {}
+}

crates/ty_module_resolver/src/lib.rs

@@ -1,24 +1,31 @@
 use std::iter::FusedIterator;
 
-pub use list::{all_modules, list_modules};
-pub use module::KnownModule;
-pub use module::Module;
-pub use path::{SearchPath, SearchPathValidationError};
-pub use resolver::SearchPaths;
-pub(crate) use resolver::file_to_module;
-pub use resolver::{
-    resolve_module, resolve_module_confident, resolve_real_module, resolve_real_module_confident,
-    resolve_real_shadowable_module,
-};
 use ruff_db::system::SystemPath;
 
-use crate::Db;
-pub(crate) use resolver::{ModuleResolveMode, SearchPathIterator, search_paths};
+pub use db::Db;
+pub use module::KnownModule;
+pub use module::Module;
+pub use module_name::{ModuleName, ModuleNameResolutionError};
+pub use path::{SearchPath, SearchPathError};
+pub use resolve::{
+    SearchPaths, file_to_module, resolve_module, resolve_module_confident, resolve_real_module,
+    resolve_real_module_confident, resolve_real_shadowable_module,
+};
+pub use settings::{MisconfigurationMode, SearchPathSettings, SearchPathSettingsError};
+pub use typeshed::{
+    PyVersionRange, TypeshedVersions, TypeshedVersionsParseError, vendored_typeshed_versions,
+};
 
+pub use list::{all_modules, list_modules};
+pub use resolve::{ModuleResolveMode, SearchPathIterator, search_paths};
+
+mod db;
 mod list;
 mod module;
+mod module_name;
 mod path;
-mod resolver;
+mod resolve;
+mod settings;
 mod typeshed;
 
 #[cfg(test)]

crates/ty_module_resolver/src/list.rs

@@ -3,12 +3,10 @@ use std::collections::btree_map::{BTreeMap, Entry};
 use ruff_python_ast::PythonVersion;
 
 use crate::db::Db;
+use crate::module::{Module, ModuleKind};
 use crate::module_name::ModuleName;
-use crate::program::Program;
-
-use super::module::{Module, ModuleKind};
-use super::path::{ModulePath, SearchPath, SystemOrVendoredPathRef};
-use super::resolver::{ModuleResolveMode, ResolverContext, resolve_file_module, search_paths};
+use crate::path::{ModulePath, SearchPath, SystemOrVendoredPathRef};
+use crate::resolve::{ModuleResolveMode, ResolverContext, resolve_file_module, search_paths};
 
 /// List all available modules, including all sub-modules, sorted in lexicographic order.
 pub fn all_modules(db: &dyn Db) -> Vec<Module<'_>> {
@@ -100,7 +98,6 @@ fn list_modules_in<'db>(
 /// in the same directory).
 struct Lister<'db> {
     db: &'db dyn Db,
-    program: Program,
     search_path: &'db SearchPath,
     modules: BTreeMap<&'db ModuleName, Module<'db>>,
 }
@@ -109,10 +106,8 @@ impl<'db> Lister<'db> {
     /// Create new state that can accumulate modules from a list
     /// of file paths.
     fn new(db: &'db dyn Db, search_path: &'db SearchPath) -> Lister<'db> {
-        let program = Program::get(db);
         Lister {
             db,
-            program,
             search_path,
             modules: BTreeMap::new(),
         }
@@ -314,7 +309,7 @@ impl<'db> Lister<'db> {
     /// Returns the Python version we want to perform module resolution
     /// with.
     fn python_version(&self) -> PythonVersion {
-        self.program.python_version(self.db)
+        self.db.python_version()
     }
 
     /// Constructs a resolver context for use with some APIs that require it.
@@ -382,20 +377,17 @@ mod tests {
     use camino::{Utf8Component, Utf8Path};
     use ruff_db::Db as _;
     use ruff_db::files::{File, FilePath, FileRootKind};
-    use ruff_db::system::{
-        DbWithTestSystem, DbWithWritableSystem, OsSystem, SystemPath, SystemPathBuf,
-    };
+    use ruff_db::system::{DbWithTestSystem, DbWithWritableSystem, SystemPath, SystemPathBuf};
     use ruff_db::testing::assert_function_query_was_not_run;
     use ruff_python_ast::PythonVersion;
 
     use crate::db::{Db, tests::TestDb};
-    use crate::module_resolver::module::Module;
-    use crate::module_resolver::resolver::{
+    use crate::module::Module;
+    use crate::resolve::{
         ModuleResolveMode, ModuleResolveModeIngredient, dynamic_resolution_paths,
     };
-    use crate::module_resolver::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
-    use crate::program::{Program, ProgramSettings, SearchPathSettings};
-    use crate::{PythonPlatform, PythonVersionSource, PythonVersionWithSource};
+    use crate::settings::SearchPathSettings;
+    use crate::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
 
     use super::list_modules;
 
@@ -940,7 +932,7 @@ mod tests {
     fn symlink() -> anyhow::Result<()> {
         use anyhow::Context;
 
-        let mut db = TestDb::new();
+        let mut db = TestDb::new().with_python_version(PythonVersion::PY38);
 
         let temp_dir = tempfile::TempDir::with_prefix("PREFIX-SENTINEL")?;
         let root = temp_dir
@@ -948,7 +940,7 @@ mod tests {
             .canonicalize()
             .context("Failed to canonicalize temp dir")?;
         let root = SystemPath::from_std_path(&root).unwrap();
-        db.use_system(OsSystem::new(root));
+        db.use_system(ruff_db::system::OsSystem::new(root));
 
         let src = root.join("src");
         let site_packages = root.join("site-packages");
@@ -965,26 +957,21 @@ mod tests {
         std::fs::write(foo.as_std_path(), "")?;
         std::os::unix::fs::symlink(foo.as_std_path(), bar.as_std_path())?;
 
-        db.files().try_add_root(&db, &src, FileRootKind::Project);
+        let settings = SearchPathSettings {
+            src_roots: vec![src.clone()],
+            custom_typeshed: Some(custom_typeshed),
+            site_packages_paths: vec![site_packages],
+            ..SearchPathSettings::empty()
+        };
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource {
-                    version: PythonVersion::PY38,
-                    source: PythonVersionSource::default(),
-                },
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    custom_typeshed: Some(custom_typeshed),
-                    site_packages_paths: vec![site_packages],
-                    ..SearchPathSettings::new(vec![src])
-                }
+        db.set_search_paths(
+            settings
                 .to_search_paths(db.system(), db.vendored())
                 .expect("Valid search path settings"),
-            },
         );
 
+        db.files().try_add_root(&db, &src, FileRootKind::Project);
+
         // From the original test in the "resolve this module"
         // implementation, this test seems to symlink a Python module
         // and assert that they are treated as two distinct modules.
@@ -1479,18 +1466,15 @@ not_a_directory
         db.files()
             .try_add_root(&db, SystemPath::new("/src"), FileRootKind::Project);
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    site_packages_paths: vec![venv_site_packages],
-                    ..SearchPathSettings::new(vec![src.to_path_buf()])
-                }
+        let settings = SearchPathSettings {
+            site_packages_paths: vec![venv_site_packages],
+            ..SearchPathSettings::new(vec![src.to_path_buf()])
+        };
+
+        db.set_search_paths(
+            settings
                 .to_search_paths(db.system(), db.vendored())
                 .expect("Valid search path settings"),
-            },
         );
 
         insta::assert_debug_snapshot!(
@@ -1533,18 +1517,15 @@ not_a_directory
         db.files()
             .try_add_root(&db, SystemPath::new("/src"), FileRootKind::Project);
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    site_packages_paths: vec![venv_site_packages, system_site_packages],
-                    ..SearchPathSettings::new(vec![SystemPathBuf::from("/src")])
-                }
+        let settings = SearchPathSettings {
+            site_packages_paths: vec![venv_site_packages, system_site_packages],
+            ..SearchPathSettings::new(vec![SystemPathBuf::from("/src")])
+        };
+
+        db.set_search_paths(
+            settings
                 .to_search_paths(db.system(), db.vendored())
                 .expect("Valid search path settings"),
-            },
         );
 
         // The editable installs discovered from the `.pth` file in the
@@ -1585,7 +1566,7 @@ not_a_directory
     #[test]
     #[cfg(unix)]
     fn case_sensitive_resolution_with_symlinked_directory() -> anyhow::Result<()> {
-        use anyhow::Context;
+        use anyhow::Context as _;
 
         let temp_dir = tempfile::TempDir::with_prefix("PREFIX-SENTINEL")?;
         let root = SystemPathBuf::from_path_buf(
@@ -1602,7 +1583,7 @@ not_a_directory
         let a_package_target = root.join("a-package");
         let a_src = src.join("a");
 
-        db.use_system(OsSystem::new(&root));
+        db.use_system(ruff_db::system::OsSystem::new(&root));
 
         db.write_file(
             a_package_target.join("__init__.py"),
@@ -1621,16 +1602,11 @@ not_a_directory
 
         db.files().try_add_root(&db, &root, FileRootKind::Project);
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings::new(vec![src])
-                    .to_search_paths(db.system(), db.vendored())
-                    .expect("valid search path settings"),
-            },
-        );
+        let settings = SearchPathSettings::new(vec![src]);
+        let search_paths = settings
+            .to_search_paths(db.system(), db.vendored())
+            .expect("valid search path settings");
+        db.set_search_paths(search_paths);
 
         insta::with_settings!({
             // Temporary directory often have random chars in them, so
@@ -1662,18 +1638,14 @@ not_a_directory
         db.files()
             .try_add_root(&db, &project_directory, FileRootKind::Project);
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    site_packages_paths: vec![site_packages],
-                    ..SearchPathSettings::new(vec![project_directory])
-                }
+        let settings = SearchPathSettings {
+            site_packages_paths: vec![site_packages],
+            ..SearchPathSettings::new(vec![project_directory])
+        };
+        db.set_search_paths(
+            settings
                 .to_search_paths(db.system(), db.vendored())
                 .unwrap(),
-            },
         );
 
         insta::assert_debug_snapshot!(
@@ -1820,16 +1792,11 @@ not_a_directory
         db.files()
             .try_add_root(&db, SystemPath::new("/"), FileRootKind::Project);
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings::new(vec![project_directory])
-                    .to_search_paths(db.system(), db.vendored())
-                    .unwrap(),
-            },
-        );
+        let settings = SearchPathSettings::new(vec![project_directory]);
+        let search_paths = settings
+            .to_search_paths(db.system(), db.vendored())
+            .expect("Valid search path settings");
+        db.set_search_paths(search_paths);
 
         insta::assert_debug_snapshot!(
             list_snapshot_filter(&db, |m| m.name(&db).as_str() == "foo"),

crates/ty_module_resolver/src/module.rs

@@ -7,10 +7,9 @@ use ruff_db::vendored::VendoredPath;
 use salsa::Database;
 use salsa::plumbing::AsId;
 
-use super::path::SearchPath;
 use crate::Db;
 use crate::module_name::ModuleName;
-use crate::module_resolver::path::SystemOrVendoredPathRef;
+use crate::path::{SearchPath, SystemOrVendoredPathRef};
 
 /// Representation of a Python module.
 #[derive(Clone, Copy, Eq, Hash, PartialEq, salsa::Supertype, salsa::Update)]
@@ -330,16 +329,14 @@ pub enum KnownModule {
     TyExtensions,
     #[strum(serialize = "importlib")]
     ImportLib,
-    #[cfg(test)]
     #[strum(serialize = "unittest.mock")]
     UnittestMock,
-    #[cfg(test)]
     Uuid,
     Warnings,
 }
 
 impl KnownModule {
-    pub(crate) const fn as_str(self) -> &'static str {
+    pub const fn as_str(self) -> &'static str {
         match self {
             Self::Builtins => "builtins",
             Self::Enum => "enum",
@@ -360,23 +357,18 @@ impl KnownModule {
             Self::TyExtensions => "ty_extensions",
             Self::ImportLib => "importlib",
             Self::Warnings => "warnings",
-            #[cfg(test)]
             Self::UnittestMock => "unittest.mock",
-            #[cfg(test)]
             Self::Uuid => "uuid",
             Self::Templatelib => "string.templatelib",
         }
     }
 
-    pub(crate) fn name(self) -> ModuleName {
+    pub fn name(self) -> ModuleName {
         ModuleName::new_static(self.as_str())
             .unwrap_or_else(|| panic!("{self} should be a valid module name!"))
     }
 
-    pub(crate) fn try_from_search_path_and_name(
-        search_path: &SearchPath,
-        name: &ModuleName,
-    ) -> Option<Self> {
+    fn try_from_search_path_and_name(search_path: &SearchPath, name: &ModuleName) -> Option<Self> {
         if search_path.is_standard_library() {
             Self::from_str(name.as_str()).ok()
         } else {
@@ -384,23 +376,23 @@ impl KnownModule {
         }
     }
 
-    pub(crate) const fn is_builtins(self) -> bool {
+    pub const fn is_builtins(self) -> bool {
         matches!(self, Self::Builtins)
     }
 
-    pub(crate) const fn is_typing(self) -> bool {
+    pub const fn is_typing(self) -> bool {
         matches!(self, Self::Typing)
     }
 
-    pub(crate) const fn is_ty_extensions(self) -> bool {
+    pub const fn is_ty_extensions(self) -> bool {
         matches!(self, Self::TyExtensions)
     }
 
-    pub(crate) const fn is_inspect(self) -> bool {
+    pub const fn is_inspect(self) -> bool {
         matches!(self, Self::Inspect)
     }
 
-    pub(crate) const fn is_importlib(self) -> bool {
+    pub const fn is_importlib(self) -> bool {
         matches!(self, Self::ImportLib)
     }
 }

crates/ty_module_resolver/src/module_name.rs

@@ -8,7 +8,8 @@ use ruff_db::files::File;
 use ruff_python_ast as ast;
 use ruff_python_stdlib::identifiers::is_identifier;
 
-use crate::{db::Db, module_resolver::file_to_module};
+use crate::db::Db;
+use crate::resolve::file_to_module;
 
 /// A module name, e.g. `foo.bar`.
 ///
@@ -47,7 +48,7 @@ impl ModuleName {
     /// ## Examples
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// assert_eq!(ModuleName::new_static("foo.bar").as_deref(), Some("foo.bar"));
     /// assert_eq!(ModuleName::new_static(""), None);
@@ -73,7 +74,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// assert_eq!(ModuleName::new_static("foo.bar.baz").unwrap().components().collect::<Vec<_>>(), vec!["foo", "bar", "baz"]);
     /// ```
@@ -87,7 +88,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// assert_eq!(ModuleName::new_static("foo.bar").unwrap().parent(), Some(ModuleName::new_static("foo").unwrap()));
     /// assert_eq!(ModuleName::new_static("foo.bar.baz").unwrap().parent(), Some(ModuleName::new_static("foo.bar").unwrap()));
@@ -106,7 +107,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// assert!(ModuleName::new_static("foo.bar").unwrap().starts_with(&ModuleName::new_static("foo").unwrap()));
     ///
@@ -142,7 +143,7 @@ impl ModuleName {
     /// module name:
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// let this = ModuleName::new_static("importlib.resources").unwrap();
     /// let parent = ModuleName::new_static("importlib").unwrap();
@@ -156,7 +157,7 @@ impl ModuleName {
     /// This shows some cases where it isn't a parent:
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// let this = ModuleName::new_static("importliblib.resources").unwrap();
     /// let parent = ModuleName::new_static("importlib").unwrap();
@@ -199,7 +200,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// assert_eq!(&*ModuleName::from_components(["a"]).unwrap(), "a");
     /// assert_eq!(&*ModuleName::from_components(["a", "b"]).unwrap(), "a.b");
@@ -240,7 +241,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// let mut module_name = ModuleName::new_static("foo").unwrap();
     /// module_name.extend(&ModuleName::new_static("bar").unwrap());
@@ -258,7 +259,7 @@ impl ModuleName {
     /// # Examples
     ///
     /// ```
-    /// use ty_python_semantic::ModuleName;
+    /// use ty_module_resolver::ModuleName;
     ///
     /// assert_eq!(
     ///     ModuleName::new_static("foo.bar.baz").unwrap().ancestors().collect::<Vec<_>>(),
@@ -314,7 +315,7 @@ impl ModuleName {
     /// Computes the absolute module name for the package this file belongs to.
     ///
     /// i.e. this resolves `.`
-    pub(crate) fn package_for_file(
+    pub fn package_for_file(
         db: &dyn Db,
         importing_file: File,
     ) -> Result<Self, ModuleNameResolutionError> {

crates/ty_module_resolver/src/path.rs

@@ -8,11 +8,10 @@ use ruff_db::files::{File, FileError, FilePath, system_path_to_file, vendored_pa
 use ruff_db::system::{System, SystemPath, SystemPathBuf};
 use ruff_db::vendored::{VendoredPath, VendoredPathBuf};
 
-use super::typeshed::{TypeshedVersionsParseError, TypeshedVersionsQueryResult, typeshed_versions};
 use crate::Db;
 use crate::module_name::ModuleName;
-use crate::module_resolver::resolver::{PyTyped, ResolverContext};
-use crate::site_packages::SitePackagesDiscoveryError;
+use crate::resolve::{PyTyped, ResolverContext};
+use crate::typeshed::{TypeshedVersionsQueryResult, typeshed_versions};
 
 /// A path that points to a Python module.
 ///
@@ -397,13 +396,8 @@ fn query_stdlib_version(
     typeshed_versions(*db).query_module(&module_name, *python_version)
 }
 
-/// Enumeration describing the various ways in which validation of a search path might fail.
-///
-/// If validation fails for a search path derived from the user settings,
-/// a message must be displayed to the user,
-/// as type checking cannot be done reliably in these circumstances.
 #[derive(Debug, thiserror::Error)]
-pub enum SearchPathValidationError {
+pub enum SearchPathError {
     /// The path provided by the user was not a directory
     #[error("{0} does not point to a directory")]
     NotADirectory(SystemPathBuf),
@@ -413,41 +407,9 @@ pub enum SearchPathValidationError {
     /// (This is only relevant for stdlib search paths.)
     #[error("The directory at {0} has no `stdlib/` subdirectory")]
     NoStdlibSubdirectory(SystemPathBuf),
-
-    /// The typeshed path provided by the user is a directory,
-    /// but `stdlib/VERSIONS` could not be read.
-    /// (This is only relevant for stdlib search paths.)
-    #[error("Failed to read the custom typeshed versions file '{path}'")]
-    FailedToReadVersionsFile {
-        path: SystemPathBuf,
-        #[source]
-        error: std::io::Error,
-    },
-
-    /// The path provided by the user is a directory,
-    /// and a `stdlib/VERSIONS` file exists, but it fails to parse.
-    /// (This is only relevant for stdlib search paths.)
-    #[error(transparent)]
-    VersionsParseError(TypeshedVersionsParseError),
-
-    /// Failed to discover the site-packages for the configured virtual environment.
-    #[error("Failed to discover the site-packages directory")]
-    SitePackagesDiscovery(#[source] SitePackagesDiscoveryError),
 }
 
-impl From<TypeshedVersionsParseError> for SearchPathValidationError {
-    fn from(value: TypeshedVersionsParseError) -> Self {
-        Self::VersionsParseError(value)
-    }
-}
-
-impl From<SitePackagesDiscoveryError> for SearchPathValidationError {
-    fn from(value: SitePackagesDiscoveryError) -> Self {
-        Self::SitePackagesDiscovery(value)
-    }
-}
-
-type SearchPathResult<T> = Result<T, SearchPathValidationError>;
+type SearchPathResult<T> = Result<T, SearchPathError>;
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, get_size2::GetSize)]
 enum SearchPathInner {
@@ -495,7 +457,7 @@ impl SearchPath {
         if system.is_directory(&root) {
             Ok(root)
         } else {
-            Err(SearchPathValidationError::NotADirectory(root))
+            Err(SearchPathError::NotADirectory(root))
         }
     }
 
@@ -519,17 +481,15 @@ impl SearchPath {
         typeshed: &SystemPath,
     ) -> SearchPathResult<Self> {
         if !system.is_directory(typeshed) {
-            return Err(SearchPathValidationError::NotADirectory(
-                typeshed.to_path_buf(),
-            ));
+            return Err(SearchPathError::NotADirectory(typeshed.to_path_buf()));
         }
 
         let stdlib =
             Self::directory_path(system, typeshed.join("stdlib")).map_err(|err| match err {
-                SearchPathValidationError::NotADirectory(_) => {
-                    SearchPathValidationError::NoStdlibSubdirectory(typeshed.to_path_buf())
+                SearchPathError::NotADirectory(_) => {
+                    SearchPathError::NoStdlibSubdirectory(typeshed.to_path_buf())
                 }
-                err => err,
+                SearchPathError::NoStdlibSubdirectory(_) => err,
             })?;
 
         Ok(Self(Arc::new(SearchPathInner::StandardLibraryCustom(
@@ -585,7 +545,7 @@ impl SearchPath {
 
     /// Does this search path point to the standard library?
     #[must_use]
-    pub(crate) fn is_standard_library(&self) -> bool {
+    pub fn is_standard_library(&self) -> bool {
         matches!(
             &*self.0,
             SearchPathInner::StandardLibraryCustom(_)
@@ -680,7 +640,7 @@ impl SearchPath {
     }
 
     #[must_use]
-    pub(crate) fn as_system_path(&self) -> Option<&SystemPath> {
+    pub fn as_system_path(&self) -> Option<&SystemPath> {
         self.as_path().as_system_path()
     }
 
@@ -709,7 +669,7 @@ impl SearchPath {
     /// Returns a string suitable for describing what kind of search path this is
     /// in user-facing diagnostics.
     #[must_use]
-    pub(crate) fn describe_kind(&self) -> &'static str {
+    pub fn describe_kind(&self) -> &'static str {
         match *self.0 {
             SearchPathInner::Extra(_) => {
                 "extra search path specified on the CLI or in your config file"
@@ -869,8 +829,8 @@ mod tests {
     use ruff_python_ast::PythonVersion;
 
     use crate::db::tests::TestDb;
-    use crate::module_resolver::resolver::ModuleResolveMode;
-    use crate::module_resolver::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
+    use crate::resolve::ModuleResolveMode;
+    use crate::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
 
     use super::*;
 

crates/ty_module_resolver/src/resolve.rs

@@ -48,13 +48,11 @@ use ruff_python_ast::{
 };
 
 use crate::db::Db;
+use crate::module::{Module, ModuleKind};
 use crate::module_name::ModuleName;
-use crate::module_resolver::typeshed::{TypeshedVersions, vendored_typeshed_versions};
-use crate::program::MisconfigurationMode;
-use crate::{Program, SearchPathSettings};
-
-use super::module::{Module, ModuleKind};
-use super::path::{ModulePath, SearchPath, SearchPathValidationError, SystemOrVendoredPathRef};
+use crate::path::{ModulePath, SearchPath, SystemOrVendoredPathRef};
+use crate::typeshed::{TypeshedVersions, vendored_typeshed_versions};
+use crate::{MisconfigurationMode, SearchPathSettings, SearchPathSettingsError};
 
 /// Resolves a module name to a module.
 pub fn resolve_module<'db>(
@@ -137,7 +135,7 @@ pub fn resolve_real_shadowable_module<'db>(
 /// Which files should be visible when doing a module query
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, get_size2::GetSize)]
 #[allow(clippy::enum_variant_names)]
-pub(crate) enum ModuleResolveMode {
+pub enum ModuleResolveMode {
     /// Stubs are allowed to appear.
     ///
     /// This is the "normal" mode almost everything uses, as type checkers are in fact supposed
@@ -326,7 +324,7 @@ pub(crate) fn path_to_module<'db>(db: &'db dyn Db, path: &FilePath) -> Option<Mo
 /// This intuition is particularly useful for understanding why it's correct that we pass
 /// the file itself as `importing_file` to various subroutines.
 #[salsa::tracked(heap_size=ruff_memory_usage::heap_size)]
-pub(crate) fn file_to_module(db: &dyn Db, file: File) -> Option<Module<'_>> {
+pub fn file_to_module(db: &dyn Db, file: File) -> Option<Module<'_>> {
     let _span = tracing::trace_span!("file_to_module", ?file).entered();
 
     let path = SystemOrVendoredPathRef::try_from_file(db, file)?;
@@ -392,8 +390,8 @@ fn file_to_module_impl<'db, 'a>(
     None
 }
 
-pub(crate) fn search_paths(db: &dyn Db, resolve_mode: ModuleResolveMode) -> SearchPathIterator<'_> {
-    Program::get(db).search_paths(db).iter(db, resolve_mode)
+pub fn search_paths(db: &dyn Db, resolve_mode: ModuleResolveMode) -> SearchPathIterator<'_> {
+    db.search_paths().iter(db, resolve_mode)
 }
 
 /// Get the search-paths for desperate resolution of absolute imports in this file.
@@ -554,11 +552,11 @@ impl SearchPaths {
     /// This method also implements the typing spec's [module resolution order].
     ///
     /// [module resolution order]: https://typing.python.org/en/latest/spec/distributing.html#import-resolution-ordering
-    pub(crate) fn from_settings(
+    pub fn from_settings(
         settings: &SearchPathSettings,
         system: &dyn System,
         vendored: &VendoredFileSystem,
-    ) -> Result<Self, SearchPathValidationError> {
+    ) -> Result<Self, SearchPathSettingsError> {
         fn canonicalize(path: &SystemPath, system: &dyn System) -> SystemPathBuf {
             system
                 .canonicalize_path(path)
@@ -586,7 +584,7 @@ impl SearchPaths {
                     if *misconfiguration_mode == MisconfigurationMode::UseDefault {
                         tracing::debug!("Skipping invalid extra search-path: {err}");
                     } else {
-                        return Err(err);
+                        return Err(err.into());
                     }
                 }
             }
@@ -600,7 +598,7 @@ impl SearchPaths {
                     if *misconfiguration_mode == MisconfigurationMode::UseDefault {
                         tracing::debug!("Skipping invalid first-party search-path: {err}");
                     } else {
-                        return Err(err);
+                        return Err(err.into());
                     }
                 }
             }
@@ -614,12 +612,10 @@ impl SearchPaths {
 
             let results = system
                 .read_to_string(&versions_path)
-                .map_err(
-                    |error| SearchPathValidationError::FailedToReadVersionsFile {
-                        path: versions_path,
-                        error,
-                    },
-                )
+                .map_err(|error| SearchPathSettingsError::FailedToReadVersionsFile {
+                    path: versions_path,
+                    error,
+                })
                 .and_then(|versions_content| Ok(versions_content.parse()?))
                 .and_then(|parsed| Ok((parsed, SearchPath::custom_stdlib(system, &typeshed)?)));
 
@@ -653,7 +649,7 @@ impl SearchPaths {
                         tracing::debug!("Skipping invalid real-stdlib search-path: {err}");
                         None
                     } else {
-                        return Err(err);
+                        return Err(err.into());
                     }
                 }
             }
@@ -669,9 +665,9 @@ impl SearchPaths {
                 Ok(path) => site_packages.push(path),
                 Err(err) => {
                     if settings.misconfiguration_mode == MisconfigurationMode::UseDefault {
-                        tracing::debug!("Skipping invalid real-stdlib search-path: {err}");
+                        tracing::debug!("Skipping invalid site-packages search-path: {err}");
                     } else {
-                        return Err(err);
+                        return Err(err.into());
                     }
                 }
             }
@@ -709,13 +705,11 @@ impl SearchPaths {
         // preserve this behaviour to avoid getting into the weeds of corner cases.)
         let stdlib_path_is_shadowed = stdlib_path
             .as_system_path()
-            .map(|path| seen_paths.contains(path))
-            .unwrap_or(false);
+            .is_some_and(|path| seen_paths.contains(path));
         let real_stdlib_path_is_shadowed = real_stdlib_path
             .as_ref()
             .and_then(SearchPath::as_system_path)
-            .map(|path| seen_paths.contains(path))
-            .unwrap_or(false);
+            .is_some_and(|path| seen_paths.contains(path));
 
         let stdlib_path = if stdlib_path_is_shadowed {
             None
@@ -737,8 +731,21 @@ impl SearchPaths {
         })
     }
 
+    /// Returns a new `SearchPaths` with no search paths configured.
+    ///
+    /// This is primarily useful for testing.
+    pub fn empty(vendored: &VendoredFileSystem) -> Self {
+        Self {
+            static_paths: vec![],
+            stdlib_path: Some(SearchPath::vendored_stdlib()),
+            real_stdlib_path: None,
+            site_packages: vec![],
+            typeshed_versions: vendored_typeshed_versions(vendored),
+        }
+    }
+
     /// Registers the file roots for all non-dynamically discovered search paths that aren't first-party.
-    pub(crate) fn try_register_static_roots(&self, db: &dyn Db) {
+    pub fn try_register_static_roots(&self, db: &dyn Db) {
         let files = db.files();
         for path in self
             .static_paths
@@ -779,13 +786,13 @@ impl SearchPaths {
         }
     }
 
-    pub(crate) fn custom_stdlib(&self) -> Option<&SystemPath> {
+    pub fn custom_stdlib(&self) -> Option<&SystemPath> {
         self.stdlib_path
             .as_ref()
             .and_then(SearchPath::as_system_path)
     }
 
-    pub(crate) fn typeshed_versions(&self) -> &TypeshedVersions {
+    pub fn typeshed_versions(&self) -> &TypeshedVersions {
         &self.typeshed_versions
     }
 }
@@ -811,7 +818,7 @@ pub(crate) fn dynamic_resolution_paths<'db>(
         site_packages,
         typeshed_versions: _,
         real_stdlib_path,
-    } = Program::get(db).search_paths(db);
+    } = db.search_paths();
 
     let mut dynamic_paths = Vec::new();
 
@@ -932,7 +939,7 @@ pub(crate) fn dynamic_resolution_paths<'db>(
 /// are only calculated lazily.
 ///
 /// [`sys.path` at runtime]: https://docs.python.org/3/library/site.html#module-site
-pub(crate) struct SearchPathIterator<'db> {
+pub struct SearchPathIterator<'db> {
     db: &'db dyn Db,
     static_paths: std::slice::Iter<'db, SearchPath>,
     stdlib_path: Option<&'db SearchPath>,
@@ -1101,8 +1108,7 @@ fn resolve_name_impl<'a>(
     mode: ModuleResolveMode,
     search_paths: impl Iterator<Item = &'a SearchPath>,
 ) -> Option<ResolvedName> {
-    let program = Program::get(db);
-    let python_version = program.python_version(db);
+    let python_version = db.python_version();
     let resolver_state = ResolverContext::new(db, python_version, mode);
     let is_non_shadowable = mode.is_non_shadowable(python_version.minor, name.as_str());
 
@@ -1740,10 +1746,9 @@ mod tests {
     use ruff_python_ast::PythonVersion;
 
     use crate::db::tests::TestDb;
+    use crate::module::ModuleKind;
     use crate::module_name::ModuleName;
-    use crate::module_resolver::module::ModuleKind;
-    use crate::module_resolver::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
-    use crate::{ProgramSettings, PythonPlatform, PythonVersionWithSource};
+    use crate::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
 
     use super::*;
 
@@ -2267,15 +2272,11 @@ mod tests {
     #[cfg(target_family = "unix")]
     fn symlink() -> anyhow::Result<()> {
         use anyhow::Context;
-
-        use crate::{
-            PythonPlatform, PythonVersionSource, PythonVersionWithSource, program::Program,
-        };
         use ruff_db::system::{OsSystem, SystemPath};
 
         use crate::db::tests::TestDb;
 
-        let mut db = TestDb::new();
+        let mut db = TestDb::new().with_python_version(PythonVersion::PY38);
 
         let temp_dir = tempfile::tempdir()?;
         let root = temp_dir
@@ -2300,22 +2301,15 @@ mod tests {
         std::fs::write(foo.as_std_path(), "")?;
         std::os::unix::fs::symlink(foo.as_std_path(), bar.as_std_path())?;
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource {
-                    version: PythonVersion::PY38,
-                    source: PythonVersionSource::default(),
-                },
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    custom_typeshed: Some(custom_typeshed),
-                    site_packages_paths: vec![site_packages],
-                    ..SearchPathSettings::new(vec![src.clone()])
-                }
-                .to_search_paths(db.system(), db.vendored())
-                .expect("Valid search path settings"),
-            },
+        db.set_search_paths(
+            SearchPathSettings {
+                src_roots: vec![src.clone()],
+                custom_typeshed: Some(custom_typeshed),
+                site_packages_paths: vec![site_packages],
+                ..SearchPathSettings::empty()
+            }
+            .to_search_paths(db.system(), db.vendored())
+            .expect("Valid search path settings"),
         );
 
         let foo_module =
@@ -2848,18 +2842,13 @@ not_a_directory
         ])
         .unwrap();
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    site_packages_paths: vec![venv_site_packages, system_site_packages],
-                    ..SearchPathSettings::new(vec![SystemPathBuf::from("/src")])
-                }
-                .to_search_paths(db.system(), db.vendored())
-                .expect("Valid search path settings"),
-            },
+        db.set_search_paths(
+            SearchPathSettings {
+                site_packages_paths: vec![venv_site_packages, system_site_packages],
+                ..SearchPathSettings::new(vec![SystemPathBuf::from("/src")])
+            }
+            .to_search_paths(db.system(), db.vendored())
+            .expect("Valid search path settings"),
         );
 
         // The editable installs discovered from the `.pth` file in the first `site-packages` directory
@@ -2924,15 +2913,10 @@ not_a_directory
         std::os::unix::fs::symlink(a_package_target.as_std_path(), a_src.as_std_path())
             .context("Failed to symlink `src/a` to `a-package`")?;
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings::new(vec![src])
-                    .to_search_paths(db.system(), db.vendored())
-                    .expect("valid search path settings"),
-            },
+        db.set_search_paths(
+            SearchPathSettings::new(vec![src])
+                .to_search_paths(db.system(), db.vendored())
+                .expect("Valid search path settings"),
         );
 
         // Now try to resolve the module `A` (note the capital `A` instead of `a`).
@@ -2964,19 +2948,14 @@ not_a_directory
         let mut db = TestDb::new();
         db.write_file(&installed_foo_module, "").unwrap();
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource::default(),
-                python_platform: PythonPlatform::default(),
-                search_paths: SearchPathSettings {
-                    site_packages_paths: vec![site_packages.clone()],
-                    ..SearchPathSettings::new(vec![project_directory])
-                }
-                .to_search_paths(db.system(), db.vendored())
-                .unwrap(),
-            },
-        );
+        let search_paths = SearchPathSettings {
+            src_roots: vec![project_directory],
+            site_packages_paths: vec![site_packages.clone()],
+            ..SearchPathSettings::empty()
+        }
+        .to_search_paths(db.system(), db.vendored())
+        .expect("Valid search path settings");
+        db.set_search_paths(search_paths);
 
         let foo_module_file = File::new(&db, FilePath::System(installed_foo_module));
         let module = file_to_module(&db, foo_module_file).unwrap();

crates/ty_module_resolver/src/settings.rs

@@ -0,0 +1,105 @@
+//! Search path configuration settings.
+
+use ruff_db::system::{System, SystemPathBuf};
+use ruff_db::vendored::VendoredFileSystem;
+
+use crate::path::SearchPathError;
+use crate::resolve::SearchPaths;
+use crate::typeshed::TypeshedVersionsParseError;
+
+/// How to handle apparent misconfiguration
+#[derive(PartialEq, Eq, Debug, Copy, Clone, Default, get_size2::GetSize)]
+pub enum MisconfigurationMode {
+    /// Settings Failure Is Not An Error.
+    ///
+    /// This is used by the default database, which we are incentivized to make infallible,
+    /// while still trying to "do our best" to set things up properly where we can.
+    UseDefault,
+    /// Settings Failure Is An Error.
+    #[default]
+    Fail,
+}
+
+/// Configures the search paths for module resolution.
+#[derive(Eq, PartialEq, Debug, Clone)]
+pub struct SearchPathSettings {
+    /// List of user-provided paths that should take first priority in the module resolution.
+    /// Examples in other type checkers are mypy's MYPYPATH environment variable,
+    /// or pyright's stubPath configuration setting.
+    pub extra_paths: Vec<SystemPathBuf>,
+
+    /// The root of the project, used for finding first-party modules.
+    pub src_roots: Vec<SystemPathBuf>,
+
+    /// Optional path to a "custom typeshed" directory on disk for us to use for standard-library types.
+    /// If this is not provided, we will fallback to our vendored typeshed stubs for the stdlib,
+    /// bundled as a zip file in the binary
+    pub custom_typeshed: Option<SystemPathBuf>,
+
+    /// List of site packages paths to use.
+    pub site_packages_paths: Vec<SystemPathBuf>,
+
+    /// Option path to the real stdlib on the system, and not some instance of typeshed.
+    ///
+    /// We should ideally only ever use this for things like goto-definition,
+    /// where typeshed isn't the right answer.
+    pub real_stdlib_path: Option<SystemPathBuf>,
+
+    /// How to handle apparent misconfiguration
+    pub misconfiguration_mode: MisconfigurationMode,
+}
+
+impl SearchPathSettings {
+    pub fn new(src_roots: Vec<SystemPathBuf>) -> Self {
+        Self {
+            src_roots,
+            ..SearchPathSettings::empty()
+        }
+    }
+
+    pub fn empty() -> Self {
+        SearchPathSettings {
+            src_roots: vec![],
+            extra_paths: vec![],
+            custom_typeshed: None,
+            site_packages_paths: vec![],
+            real_stdlib_path: None,
+            misconfiguration_mode: MisconfigurationMode::Fail,
+        }
+    }
+
+    pub fn to_search_paths(
+        &self,
+        system: &dyn System,
+        vendored: &VendoredFileSystem,
+    ) -> Result<SearchPaths, SearchPathSettingsError> {
+        SearchPaths::from_settings(self, system, vendored)
+    }
+}
+
+/// Enumeration describing the various ways in which validation of the search paths options might fail.
+///
+/// If validation fails for a search path derived from the user settings,
+/// a message must be displayed to the user,
+/// as type checking cannot be done reliably in these circumstances.
+#[derive(Debug, thiserror::Error)]
+pub enum SearchPathSettingsError {
+    #[error(transparent)]
+    InvalidSearchPath(#[from] SearchPathError),
+
+    /// The typeshed path provided by the user is a directory,
+    /// but `stdlib/VERSIONS` could not be read.
+    /// (This is only relevant for stdlib search paths.)
+    #[error("Failed to read the custom typeshed versions file '{path}'")]
+    FailedToReadVersionsFile {
+        path: SystemPathBuf,
+        #[source]
+        error: std::io::Error,
+    },
+
+    /// The path provided by the user is a directory,
+    /// and a `stdlib/VERSIONS` file exists, but it fails to parse.
+    /// (This is only relevant for stdlib search paths.)
+    #[error(transparent)]
+    VersionsParseError(#[from] TypeshedVersionsParseError),
+}

crates/ty_module_resolver/src/testing.rs

@@ -1,4 +1,4 @@
-use ruff_db::Db;
+use ruff_db::Db as _;
 use ruff_db::files::FileRootKind;
 use ruff_db::system::{
     DbWithTestSystem as _, DbWithWritableSystem as _, SystemPath, SystemPathBuf,
@@ -7,8 +7,7 @@ use ruff_db::vendored::VendoredPathBuf;
 use ruff_python_ast::PythonVersion;
 
 use crate::db::tests::TestDb;
-use crate::program::{Program, SearchPathSettings};
-use crate::{ProgramSettings, PythonPlatform, PythonVersionSource, PythonVersionWithSource};
+use crate::settings::SearchPathSettings;
 
 /// A test case for the module resolver.
 ///
@@ -20,7 +19,7 @@ pub(crate) struct TestCase<T> {
     pub(crate) stdlib: T,
     // Most test cases only ever need a single `site-packages` directory,
     // so this is a single directory instead of a `Vec` of directories,
-    // like it is in `ruff_db::Program`.
+    // like it is in `SearchPaths`.
     pub(crate) site_packages: SystemPathBuf,
     pub(crate) python_version: PythonVersion,
 }
@@ -105,7 +104,6 @@ pub(crate) struct UnspecifiedTypeshed;
 pub(crate) struct TestCaseBuilder<T> {
     typeshed_option: T,
     python_version: PythonVersion,
-    python_platform: PythonPlatform,
     first_party_files: Vec<FileSpec>,
     site_packages_files: Vec<FileSpec>,
     // Additional file roots (beyond site_packages, src and stdlib)
@@ -166,7 +164,6 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
         Self {
             typeshed_option: UnspecifiedTypeshed,
             python_version: PythonVersion::default(),
-            python_platform: PythonPlatform::default(),
             first_party_files: vec![],
             site_packages_files: vec![],
             roots: vec![],
@@ -178,7 +175,6 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
         let TestCaseBuilder {
             typeshed_option: _,
             python_version,
-            python_platform,
             first_party_files,
             site_packages_files,
             roots,
@@ -186,7 +182,6 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
         TestCaseBuilder {
             typeshed_option: VendoredTypeshed,
             python_version,
-            python_platform,
             first_party_files,
             site_packages_files,
             roots,
@@ -201,7 +196,6 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
         let TestCaseBuilder {
             typeshed_option: _,
             python_version,
-            python_platform,
             first_party_files,
             site_packages_files,
             roots,
@@ -210,7 +204,6 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
         TestCaseBuilder {
             typeshed_option: typeshed,
             python_version,
-            python_platform,
             first_party_files,
             site_packages_files,
             roots,
@@ -241,18 +234,29 @@ impl TestCaseBuilder<MockedTypeshed> {
         let TestCaseBuilder {
             typeshed_option,
             python_version,
-            python_platform,
             first_party_files,
             site_packages_files,
             roots,
         } = self;
 
-        let mut db = TestDb::new();
+        let mut db = TestDb::new().with_python_version(python_version);
 
         let site_packages =
             Self::write_mock_directory(&mut db, "/site-packages", site_packages_files);
         let src = Self::write_mock_directory(&mut db, "/src", first_party_files);
         let typeshed = Self::build_typeshed_mock(&mut db, &typeshed_option);
+        let stdlib = typeshed.join("stdlib");
+
+        let search_paths = SearchPathSettings {
+            src_roots: vec![src.clone()],
+            custom_typeshed: Some(typeshed),
+            site_packages_paths: vec![site_packages.clone()],
+            ..SearchPathSettings::empty()
+        }
+        .to_search_paths(db.system(), db.vendored())
+        .expect("Valid search path settings");
+
+        db = db.with_search_paths(search_paths);
 
         // This root is needed for correct Salsa tracking.
         // Namely, a `SearchPath` is treated as an input, and
@@ -262,36 +266,19 @@ impl TestCaseBuilder<MockedTypeshed> {
         // here, they won't get added.
         //
         // Roots for other search paths are added as part of
-        // search path initialization in `Program::from_settings`,
+        // search path initialization in `SearchPaths::from_settings`,
         // and any remaining are added below.
         db.files()
             .try_add_root(&db, SystemPath::new("/src"), FileRootKind::Project);
 
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource {
-                    version: python_version,
-                    source: PythonVersionSource::default(),
-                },
-                python_platform,
-                search_paths: SearchPathSettings {
-                    custom_typeshed: Some(typeshed.clone()),
-                    site_packages_paths: vec![site_packages.clone()],
-                    ..SearchPathSettings::new(vec![src.clone()])
-                }
-                .to_search_paths(db.system(), db.vendored())
-                .expect("valid search path settings"),
-            },
-        );
-
-        let stdlib = typeshed.join("stdlib");
         db.files()
             .try_add_root(&db, &stdlib, FileRootKind::LibrarySearchPath);
+
         for root in &roots {
             db.files()
                 .try_add_root(&db, root, FileRootKind::LibrarySearchPath);
         }
+
         TestCase {
             db,
             src,
@@ -324,42 +311,34 @@ impl TestCaseBuilder<VendoredTypeshed> {
         let TestCaseBuilder {
             typeshed_option: VendoredTypeshed,
             python_version,
-            python_platform,
             first_party_files,
             site_packages_files,
             roots,
         } = self;
 
-        let mut db = TestDb::new();
+        let mut db = TestDb::new().with_python_version(python_version);
 
         let site_packages =
             Self::write_mock_directory(&mut db, "/site-packages", site_packages_files);
         let src = Self::write_mock_directory(&mut db, "/src", first_party_files);
 
+        let search_paths = SearchPathSettings {
+            src_roots: vec![src.clone()],
+            site_packages_paths: vec![site_packages.clone()],
+            ..SearchPathSettings::empty()
+        }
+        .to_search_paths(db.system(), db.vendored())
+        .expect("Valid search path settings");
+
+        db = db.with_search_paths(search_paths);
+
         db.files()
             .try_add_root(&db, SystemPath::new("/src"), FileRootKind::Project);
-
-        Program::from_settings(
-            &db,
-            ProgramSettings {
-                python_version: PythonVersionWithSource {
-                    version: python_version,
-                    source: PythonVersionSource::default(),
-                },
-                python_platform,
-                search_paths: SearchPathSettings {
-                    site_packages_paths: vec![site_packages.clone()],
-                    ..SearchPathSettings::new(vec![src.clone()])
-                }
-                .to_search_paths(db.system(), db.vendored())
-                .expect("valid search path settings"),
-            },
-        );
-
         for root in &roots {
             db.files()
                 .try_add_root(&db, root, FileRootKind::LibrarySearchPath);
         }
+
         TestCase {
             db,
             src,

crates/ty_module_resolver/src/typeshed.rs

@@ -8,13 +8,10 @@ use ruff_db::vendored::VendoredFileSystem;
 use ruff_python_ast::{PythonVersion, PythonVersionDeserializationError};
 use rustc_hash::FxHashMap;
 
-use crate::Program;
 use crate::db::Db;
 use crate::module_name::ModuleName;
 
-pub(in crate::module_resolver) fn vendored_typeshed_versions(
-    vendored: &VendoredFileSystem,
-) -> TypeshedVersions {
+pub fn vendored_typeshed_versions(vendored: &VendoredFileSystem) -> TypeshedVersions {
     TypeshedVersions::from_str(
         &vendored
             .read_to_string("stdlib/VERSIONS")
@@ -24,7 +21,7 @@ pub(in crate::module_resolver) fn vendored_typeshed_versions(
 }
 
 pub(crate) fn typeshed_versions(db: &dyn Db) -> &TypeshedVersions {
-    Program::get(db).search_paths(db).typeshed_versions()
+    db.search_paths().typeshed_versions()
 }
 
 #[derive(Debug, PartialEq, Eq, Clone)]
@@ -61,7 +58,7 @@ impl std::error::Error for TypeshedVersionsParseError {
 }
 
 #[derive(Debug, PartialEq, Eq, Clone, thiserror::Error)]
-pub(crate) enum TypeshedVersionsParseErrorKind {
+pub enum TypeshedVersionsParseErrorKind {
     #[error("File has too many lines ({0}); maximum allowed is {max_allowed}", max_allowed = NonZeroU16::MAX)]
     TooManyLines(NonZeroUsize),
     #[error("Expected every non-comment line to have exactly one colon")]
@@ -75,16 +72,16 @@ pub(crate) enum TypeshedVersionsParseErrorKind {
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, get_size2::GetSize)]
-pub(crate) struct TypeshedVersions(FxHashMap<ModuleName, PyVersionRange>);
+pub struct TypeshedVersions(FxHashMap<ModuleName, PyVersionRange>);
 
 impl TypeshedVersions {
     #[must_use]
-    pub(crate) fn exact(&self, module_name: &ModuleName) -> Option<&PyVersionRange> {
+    pub fn exact(&self, module_name: &ModuleName) -> Option<&PyVersionRange> {
         self.0.get(module_name)
     }
 
     #[must_use]
-    pub(in crate::module_resolver) fn query_module(
+    pub(crate) fn query_module(
         &self,
         module: &ModuleName,
         python_version: PythonVersion,
@@ -231,14 +228,14 @@ impl fmt::Display for TypeshedVersions {
 }
 
 #[derive(Debug, Clone, Eq, PartialEq, Hash, get_size2::GetSize)]
-pub(crate) enum PyVersionRange {
+pub enum PyVersionRange {
     AvailableFrom(RangeFrom<PythonVersion>),
     AvailableWithin(RangeInclusive<PythonVersion>),
 }
 
 impl PyVersionRange {
     #[must_use]
-    pub(crate) fn contains(&self, version: PythonVersion) -> bool {
+    pub fn contains(&self, version: PythonVersion) -> bool {
         match self {
             Self::AvailableFrom(inner) => inner.contains(&version),
             Self::AvailableWithin(inner) => inner.contains(&version),
@@ -246,7 +243,7 @@ impl PyVersionRange {
     }
 
     /// Display the version range in a way that is suitable for rendering in user-facing diagnostics.
-    pub(crate) fn diagnostic_display(&self) -> impl std::fmt::Display {
+    pub fn diagnostic_display(&self) -> impl std::fmt::Display {
         struct DiagnosticDisplay<'a>(&'a PyVersionRange);
 
         impl fmt::Display for DiagnosticDisplay<'_> {

crates/ty_project/Cargo.toml

@@ -21,6 +21,7 @@ ruff_python_ast = { workspace = true, features = ["serde"] }
 ruff_python_formatter = { workspace = true, optional = true }
 ruff_text_size = { workspace = true }
 ty_combine = { workspace = true }
+ty_module_resolver = { workspace = true }
 ty_python_semantic = { workspace = true, features = ["serde"] }
 ty_static = { workspace = true }
 ty_vendored = { workspace = true }

crates/ty_project/src/db.rs

@@ -14,8 +14,9 @@ use ruff_db::files::{File, Files};
 use ruff_db::system::System;
 use ruff_db::vendored::VendoredFileSystem;
 use salsa::{Database, Event, Setter};
+use ty_module_resolver::SearchPaths;
 use ty_python_semantic::lint::{LintRegistry, RuleSelection};
-use ty_python_semantic::{Db as SemanticDb, Program};
+use ty_python_semantic::{AnalysisSettings, Db as SemanticDb, Program};
 
 mod changes;
 
@@ -446,6 +447,13 @@ impl SalsaMemoryDump {
     }
 }
 
+#[salsa::db]
+impl ty_module_resolver::Db for ProjectDatabase {
+    fn search_paths(&self) -> &SearchPaths {
+        Program::get(self).search_paths(self)
+    }
+}
+
 #[salsa::db]
 impl SemanticDb for ProjectDatabase {
     fn should_check_file(&self, file: File) -> bool {
@@ -462,6 +470,10 @@ impl SemanticDb for ProjectDatabase {
         ty_python_semantic::default_lint_registry()
     }
 
+    fn analysis_settings(&self) -> &AnalysisSettings {
+        self.project().settings(self).analysis()
+    }
+
     fn verbose(&self) -> bool {
         self.project().verbose(self)
     }
@@ -523,9 +535,10 @@ pub(crate) mod tests {
     use ruff_db::files::{FileRootKind, Files};
     use ruff_db::system::{DbWithTestSystem, System, TestSystem};
     use ruff_db::vendored::VendoredFileSystem;
+    use ty_module_resolver::SearchPathSettings;
     use ty_python_semantic::lint::{LintRegistry, RuleSelection};
     use ty_python_semantic::{
-        Program, ProgramSettings, PythonPlatform, PythonVersionWithSource, SearchPathSettings,
+        AnalysisSettings, Program, ProgramSettings, PythonPlatform, PythonVersionWithSource,
     };
 
     use crate::db::Db;
@@ -627,6 +640,13 @@ pub(crate) mod tests {
         }
     }
 
+    #[salsa::db]
+    impl ty_module_resolver::Db for TestDb {
+        fn search_paths(&self) -> &ty_module_resolver::SearchPaths {
+            Program::get(self).search_paths(self)
+        }
+    }
+
     #[salsa::db]
     impl ty_python_semantic::Db for TestDb {
         fn should_check_file(&self, file: ruff_db::files::File) -> bool {
@@ -641,6 +661,10 @@ pub(crate) mod tests {
             ty_python_semantic::default_lint_registry()
         }
 
+        fn analysis_settings(&self) -> &AnalysisSettings {
+            self.project().settings(self).analysis()
+        }
+
         fn verbose(&self) -> bool {
             false
         }

crates/ty_project/src/db/changes.rs

@@ -245,7 +245,9 @@ impl ProjectDatabase {
 
         if result.project_changed {
             let new_project_metadata = match config_file_override {
-                Some(config_file) => ProjectMetadata::from_config_file(config_file, self.system()),
+                Some(config_file) => {
+                    ProjectMetadata::from_config_file(config_file, &project_root, self.system())
+                }
                 None => ProjectMetadata::discover(&project_root, self.system()),
             };
             match new_project_metadata {

crates/ty_project/src/metadata.rs

@@ -56,6 +56,7 @@ impl ProjectMetadata {
 
     pub fn from_config_file(
         path: SystemPathBuf,
+        root: &SystemPath,
         system: &dyn System,
     ) -> Result<Self, ProjectMetadataError> {
         tracing::debug!("Using overridden configuration file at '{path}'");
@@ -70,8 +71,8 @@ impl ProjectMetadata {
         let options = config_file.into_options();
 
         Ok(Self {
-            name: Name::new(system.current_directory().file_name().unwrap_or("root")),
-            root: system.current_directory().to_path_buf(),
+            name: Name::new(root.file_name().unwrap_or("root")),
+            root: root.to_path_buf(),
             options,
             extra_configuration_paths: vec![path],
             misconfiguration_mode: MisconfigurationMode::Fail,

crates/ty_project/src/metadata/options.rs

@@ -28,11 +28,12 @@ use std::ops::Deref;
 use std::sync::Arc;
 use thiserror::Error;
 use ty_combine::Combine;
+use ty_module_resolver::{SearchPathSettings, SearchPathSettingsError, SearchPaths};
 use ty_python_semantic::lint::{Level, LintSource, RuleSelection};
 use ty_python_semantic::{
-    MisconfigurationMode, ProgramSettings, PythonEnvironment, PythonPlatform,
-    PythonVersionFileSource, PythonVersionSource, PythonVersionWithSource, SearchPathSettings,
-    SearchPathValidationError, SearchPaths, SitePackagesPaths, SysPrefixPathOrigin,
+    AnalysisSettings, MisconfigurationMode, ProgramSettings, PythonEnvironment, PythonPlatform,
+    PythonVersionFileSource, PythonVersionSource, PythonVersionWithSource, SitePackagesPaths,
+    SysPrefixPathOrigin,
 };
 use ty_static::EnvVars;
 
@@ -86,6 +87,10 @@ pub struct Options {
     #[option_group]
     pub terminal: Option<TerminalOptions>,
 
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[option_group]
+    pub analysis: Option<AnalysisOptions>,
+
     /// Override configurations for specific file patterns.
     ///
     /// Each override specifies include/exclude patterns and rule configurations
@@ -258,7 +263,7 @@ impl Options {
         system: &dyn System,
         vendored: &VendoredFileSystem,
         misconfiguration_mode: MisconfigurationMode,
-    ) -> Result<SearchPaths, SearchPathValidationError> {
+    ) -> Result<SearchPaths, SearchPathSettingsError> {
         let environment = self.environment.or_default();
         let src = self.src.or_default();
 
@@ -434,6 +439,8 @@ impl Options {
                 color: colored::control::SHOULD_COLORIZE.should_colorize(),
             })?;
 
+        let analysis = self.analysis.or_default().to_settings();
+
         let overrides = self
             .to_overrides_settings(db, project_root, &mut diagnostics)
             .map_err(|err| ToSettingsError {
@@ -446,6 +453,7 @@ impl Options {
             rules: Arc::new(rules),
             terminal,
             src,
+            analysis,
             overrides,
         };
 
@@ -875,10 +883,7 @@ impl Rules {
                     let lint_source = match source {
                         ValueSource::File(_) => LintSource::File,
                         ValueSource::Cli => LintSource::Cli,
-
-                        ValueSource::Editor => {
-                            unreachable!("Can't configure rules from the user's editor")
-                        }
+                        ValueSource::Editor => LintSource::Editor,
                     };
                     if let Ok(severity) = Severity::try_from(**level) {
                         selection.enable(lint, severity, lint_source);
@@ -1014,7 +1019,12 @@ fn build_include_filter(
                             SubDiagnosticSeverity::Info,
                             "The pattern was specified on the CLI",
                         )),
-                        ValueSource::Editor => unreachable!("Can't configure includes from the user's editor"),
+                        ValueSource::Editor => {
+                            diagnostic.sub(SubDiagnostic::new(
+                                SubDiagnosticSeverity::Info,
+                                "The pattern was specified in the editor settings.",
+                            ))
+                        }
                     }
                 })?;
         }
@@ -1097,9 +1107,10 @@ fn build_exclude_filter(
                             SubDiagnosticSeverity::Info,
                             "The pattern was specified on the CLI",
                         )),
-                        ValueSource::Editor => unreachable!(
-                            "Can't configure excludes from the user's editor"
-                        )
+                        ValueSource::Editor => diagnostic.sub(SubDiagnostic::new(
+                            SubDiagnosticSeverity::Info,
+                            "The pattern was specified in the editor settings",
+                        ))
                     }
                 })?;
         }
@@ -1250,6 +1261,55 @@ pub struct TerminalOptions {
     pub error_on_warning: Option<bool>,
 }
 
+#[derive(
+    Debug,
+    Default,
+    Clone,
+    Eq,
+    PartialEq,
+    Combine,
+    Serialize,
+    Deserialize,
+    OptionsMetadata,
+    get_size2::GetSize,
+)]
+#[serde(rename_all = "kebab-case", deny_unknown_fields)]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct AnalysisOptions {
+    /// Whether ty should respect `type: ignore` comments.
+    ///
+    /// When set to `false`, `type: ignore` comments are treated like any other normal
+    /// comment and can't be used to suppress ty errors (you have to use `ty: ignore` instead).
+    ///
+    /// Setting this option can be useful when using ty alongside other type checkers or when
+    /// you prefer using `ty: ignore` over `type: ignore`.
+    ///
+    /// Defaults to `true`.
+    #[option(
+        default = r#"true"#,
+        value_type = "bool",
+        example = r#"
+        # Disable support for `type: ignore` comments
+        respect-type-ignore-comments = false
+        "#
+    )]
+    respect_type_ignore_comments: Option<bool>,
+}
+
+impl AnalysisOptions {
+    fn to_settings(&self) -> AnalysisSettings {
+        let AnalysisSettings {
+            respect_type_ignore_comments: respect_type_ignore_default,
+        } = AnalysisSettings::default();
+
+        AnalysisSettings {
+            respect_type_ignore_comments: self
+                .respect_type_ignore_comments
+                .unwrap_or(respect_type_ignore_default),
+        }
+    }
+}
+
 /// Configuration override that applies to specific files based on glob patterns.
 ///
 /// An override allows you to apply different rule configurations to specific

crates/ty_project/src/metadata/settings.rs

@@ -2,6 +2,7 @@ use std::sync::Arc;
 
 use ruff_db::files::File;
 use ty_combine::Combine;
+use ty_python_semantic::AnalysisSettings;
 use ty_python_semantic::lint::RuleSelection;
 
 use crate::metadata::options::{InnerOverrideOptions, OutputFormat};
@@ -25,6 +26,7 @@ pub struct Settings {
     pub(super) rules: Arc<RuleSelection>,
     pub(super) terminal: TerminalSettings,
     pub(super) src: SrcSettings,
+    pub(super) analysis: AnalysisSettings,
 
     /// Settings for configuration overrides that apply to specific file patterns.
     ///
@@ -54,6 +56,10 @@ impl Settings {
     pub fn overrides(&self) -> &[Override] {
         &self.overrides
     }
+
+    pub fn analysis(&self) -> &AnalysisSettings {
+        &self.analysis
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Default, get_size2::GetSize)]

crates/ty_project/src/watch/project_watcher.rs

@@ -5,7 +5,7 @@ use tracing::info;
 
 use ruff_cache::{CacheKey, CacheKeyHasher};
 use ruff_db::system::{SystemPath, SystemPathBuf};
-use ty_python_semantic::system_module_search_paths;
+use ty_module_resolver::system_module_search_paths;
 
 use crate::db::{Db, ProjectDatabase};
 use crate::watch::Watcher;

crates/ty_python_semantic/Cargo.toml

@@ -24,6 +24,8 @@ ruff_source_file = { workspace = true }
 ruff_text_size = { workspace = true }
 ruff_python_literal = { workspace = true }
 ruff_python_trivia = { workspace = true }
+ty_module_resolver = { workspace = true }
+ty_combine = { workspace = true }
 ty_static = { workspace = true }
 
 anyhow = { workspace = true }
@@ -56,7 +58,6 @@ strsim = "0.11.1"
 [dev-dependencies]
 ruff_db = { workspace = true, features = ["testing", "os"] }
 ruff_python_parser = { workspace = true }
-ty_python_semantic = { workspace = true, features = ["testing"] }
 ty_static = { workspace = true }
 ty_test = { workspace = true }
 ty_vendored = { workspace = true }
@@ -67,7 +68,6 @@ glob = { workspace = true }
 indoc = { workspace = true }
 insta = { workspace = true }
 pretty_assertions = { workspace = true }
-tempfile = { workspace = true }
 quickcheck = { version = "1.0.3", default-features = false }
 quickcheck_macros = { version = "1.0.0" }
 

crates/ty_python_semantic/resources/corpus/cyclic_implicit_attr_union.py

@@ -0,0 +1,10 @@
+# regression test for https://github.com/astral-sh/ty/issues/2085
+
+class Foo:
+    def __init__(self, x: int):
+        self.left = x
+        self.right = x
+    def method(self):
+        self.left, self.right = self.right, self.left
+        if self.right:
+            self.right = self.right

crates/ty_python_semantic/resources/corpus/cyclic_implicit_tuple_alias.py

@@ -0,0 +1,8 @@
+# Regression test for https://github.com/astral-sh/ty/issues/1848
+
+T = tuple[int, 'U']
+
+class C(set['U']):
+    pass
+
+type U = T | C

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

@@ -266,3 +266,12 @@ def _(
 ) -> (int, str):  # error: [invalid-type-form]
     return x
 ```
+
+### Special-cased diagnostic for `callable` used in a type expression
+
+```py
+# error: [invalid-type-form]
+# error: [invalid-type-form]
+def decorator(fn: callable) -> callable:
+    return fn
+```

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

@@ -193,8 +193,7 @@ class B:
 reveal_type(B().name_does_not_matter())  # revealed: B
 reveal_type(B().positional_only(1))  # revealed: B
 reveal_type(B().keyword_only(x=1))  # revealed: B
-# TODO: This should deally be `B`
-reveal_type(B().decorated_method())  # revealed: Self@decorated_method
+reveal_type(B().decorated_method())  # revealed: B
 
 reveal_type(B().a_property)  # revealed: B
 

crates/ty_python_semantic/resources/mdtest/attributes.md

@@ -2775,6 +2775,23 @@ reveal_type(foo.bar)  # revealed: Unknown
 reveal_type(baz.bar)  # revealed: Unknown
 ```
 
+## Diagnostic for function attribute accessed on `Callable` type
+
+<!-- snapshot-diagnostics -->
+
+```toml
+[environment]
+python-version = "3.14"
+```
+
+```py
+from typing import Callable
+
+def f(x: Callable):
+    x.__name__  # error: [unresolved-attribute]
+    x.__annotate__  # error: [unresolved-attribute]
+```
+
 ## References
 
 Some of the tests in the *Class and instance variables* section draw inspiration from

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

@@ -588,6 +588,31 @@ reveal_type(C.f2(1))  # revealed: str
 reveal_type(C().f2(1))  # revealed: str
 ```
 
+When a `@staticmethod` is decorated with `@contextmanager`, accessing it from an instance should not
+bind `self`:
+
+```py
+from contextlib import contextmanager
+from collections.abc import Iterator
+
+class D:
+    @staticmethod
+    @contextmanager
+    def ctx(num: int) -> Iterator[int]:
+        yield num
+
+    def use_ctx(self) -> None:
+        # Accessing via self should not bind self
+        with self.ctx(10) as x:
+            reveal_type(x)  # revealed: int
+
+# Accessing via class works
+reveal_type(D.ctx(5))  # revealed: _GeneratorContextManager[int, None, None]
+
+# Accessing via instance should also work (no self-binding)
+reveal_type(D().ctx(5))  # revealed: _GeneratorContextManager[int, None, None]
+```
+
 ### `__new__`
 
 `__new__` is an implicit `@staticmethod`; accessing it on an instance does not bind the `cls`

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

@@ -71,3 +71,38 @@ e = a.__replace__(x="wrong")  # error: [invalid-argument-type]
 # TODO: this should ideally also be emit an error
 e = replace(a, x="wrong")
 ```
+
+### NamedTuples
+
+NamedTuples also support the `__replace__` protocol:
+
+```py
+from typing import NamedTuple
+from copy import replace
+
+class Point(NamedTuple):
+    x: int
+    y: int
+
+reveal_type(Point.__replace__)  # revealed: (self: Self, *, x: int = ..., y: int = ...) -> Self
+```
+
+The `__replace__` method can either be called directly or through the `replace` function:
+
+```py
+a = Point(1, 2)
+
+b = a.__replace__(x=3, y=4)
+reveal_type(b)  # revealed: Point
+
+b = replace(a, x=3, y=4)
+# TODO: this should be `Point`, once we support specialization of generic protocols
+reveal_type(b)  # revealed: Unknown
+```
+
+Invalid calls to `__replace__` will raise an error:
+
+```py
+# error: [unknown-argument] "Argument `z` does not match any known parameter"
+a.__replace__(z=42)
+```

crates/ty_python_semantic/resources/mdtest/del.md

@@ -171,6 +171,8 @@ reveal_type(c.x)  # revealed: int
 
 ## Delete items
 
+### Basic item deletion
+
 Deleting an item also invalidates the narrowing by the assignment, but accessing the item itself is
 still valid.
 
@@ -189,3 +191,93 @@ def f(l: list[int]):
     del l[0]
     reveal_type(l[0])  # revealed: int
 ```
+
+### `__delitem__` without `__getitem__`
+
+A class or protocol that only defines `__delitem__` (without `__getitem__`) should still support
+item deletion. The `__delitem__` method is independent of `__getitem__`.
+
+```py
+from typing import Protocol, TypeVar
+
+KT = TypeVar("KT")
+
+class CanDelItem(Protocol[KT]):
+    def __delitem__(self, k: KT, /) -> None: ...
+
+def f(x: CanDelItem[int], k: int):
+    # This should be valid - the object has __delitem__
+    del x[k]
+
+class OnlyDelItem:
+    def __delitem__(self, key: int) -> None:
+        pass
+
+d = OnlyDelItem()
+del d[0]  # OK
+
+# error: [non-subscriptable] "Cannot subscript object of type `OnlyDelItem` with no `__getitem__` method"
+d[0]
+```
+
+### `__getitem__` without `__delitem__`
+
+A class that only defines `__getitem__` (without `__delitem__`) should not support item deletion.
+
+```py
+class OnlyGetItem:
+    def __getitem__(self, key: int) -> str:
+        return "value"
+
+g = OnlyGetItem()
+reveal_type(g[0])  # revealed: str
+
+# error: [non-subscriptable] "Cannot delete subscript on object of type `OnlyGetItem` with no `__delitem__` method"
+del g[0]
+```
+
+### TypedDict deletion
+
+Deleting a required key from a TypedDict is a type error because it would make the object no longer
+a valid instance of that TypedDict type. However, deleting `NotRequired` keys (or keys in
+`total=False` TypedDicts) is allowed.
+
+<!-- snapshot-diagnostics -->
+
+```py
+from typing_extensions import TypedDict, NotRequired
+
+class Movie(TypedDict):
+    name: str
+    year: int
+
+class PartialMovie(TypedDict, total=False):
+    name: str
+    year: int
+
+class MixedMovie(TypedDict):
+    name: str
+    year: NotRequired[int]
+
+m: Movie = {"name": "Blade Runner", "year": 1982}
+p: PartialMovie = {"name": "Test"}
+mixed: MixedMovie = {"name": "Test"}
+
+# Required keys cannot be deleted.
+# error: [invalid-argument-type]
+del m["name"]
+
+# In a partial TypedDict (`total=False`), all keys can be deleted.
+del p["name"]
+
+# `NotRequired` keys can always be deleted.
+del mixed["year"]
+
+# But required keys in mixed `TypedDict` still cannot be deleted.
+# error: [invalid-argument-type]
+del mixed["name"]
+
+# And keys that don't exist cannot be deleted.
+# error: [invalid-argument-type]
+del mixed["non_existent"]
+```

crates/ty_python_semantic/resources/mdtest/final.md

@@ -118,9 +118,13 @@ class Child(Parent):
 class OtherChild(Parent): ...
 
 class Grandchild(OtherChild):
+    # TODO: The Liskov violation here maybe shouldn't be emitted? Whether called on the
+    # type or on an instance, it will behave the same from the caller's perspective. The only
+    # difference is whether the method body gets access to `self`, which is not a
+    # concern of Liskov.
     @staticmethod
-    # TODO: we should emit a Liskov violation here too
     # error: [override-of-final-method]
+    # error: [invalid-method-override]
     def foo(): ...
     @property
     # TODO: we should emit a Liskov violation here too
@@ -267,6 +271,7 @@ class ChildOfGood(Good):
     def f(self, x: str) -> str: ...
     @overload
     def f(self, x: int) -> int: ...
+
     # error: [override-of-final-method]
     def f(self, x: int | str) -> int | str:
         return x
@@ -277,6 +282,7 @@ class Bad:
     def f(self, x: str) -> str: ...
     @overload
     def f(self, x: int) -> int: ...
+
     # error: [invalid-overload]
     def f(self, x: int | str) -> int | str:
         return x
@@ -286,6 +292,7 @@ class Bad:
     def g(self, x: str) -> str: ...
     @overload
     def g(self, x: int) -> int: ...
+
     # error: [invalid-overload]
     def g(self, x: int | str) -> int | str:
         return x
@@ -295,6 +302,7 @@ class Bad:
     @overload
     @final
     def h(self, x: int) -> int: ...
+
     # error: [invalid-overload]
     def h(self, x: int | str) -> int | str:
         return x
@@ -304,6 +312,7 @@ class Bad:
     @final
     @overload
     def i(self, x: int) -> int: ...
+
     # error: [invalid-overload]
     def i(self, x: int | str) -> int | str:
         return x
@@ -478,7 +487,8 @@ class B(A):
     #
     # TODO: we should emit a Liskov violation here too
     # error: [override-of-final-method]
-    method4 = 42; unrelated = 56  # fmt: skip
+    method4 = 42
+    unrelated = 56  # fmt: skip
 
 # Possible overrides of possibly `@final` methods...
 class C(A):
@@ -542,6 +552,7 @@ class Child(Parent):
     else:
         # Fine because this doesn't override any reachable definitions
         def foooo(self) -> None: ...
+
         # There are `@final` definitions being overridden here,
         # but the definitions that override them are unreachable
         def spam(self) -> None: ...

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

@@ -80,6 +80,7 @@ class CanIndex(Protocol[T]):
     def __getitem__(self, index: int, /) -> T: ...
 
 class ExplicitlyImplements(CanIndex[T]): ...
+class SubProtocol(CanIndex[T], Protocol): ...
 
 def takes_in_list(x: list[T]) -> list[T]:
     return x
@@ -103,6 +104,18 @@ def deep_explicit(x: ExplicitlyImplements[str]) -> None:
 def deeper_explicit(x: ExplicitlyImplements[set[str]]) -> None:
     reveal_type(takes_in_protocol(x))  # revealed: set[str]
 
+def deep_subprotocol(x: SubProtocol[str]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: str
+
+def deeper_subprotocol(x: SubProtocol[set[str]]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: set[str]
+
+def itself(x: CanIndex[str]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: str
+
+def deep_itself(x: CanIndex[set[str]]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: set[str]
+
 def takes_in_type(x: type[T]) -> type[T]:
     return x
 

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

@@ -144,7 +144,7 @@ class Dict[T](TypedDict):
 
 type DictInt = Dict[int]
 
-# error: [non-subscriptable] "Cannot subscript non-generic type alias: `Dict` is already specialized"
+# error: [non-subscriptable] "Cannot subscript non-generic type alias: `Dict[int]` is already specialized"
 def _(x: DictInt[int]):
     reveal_type(x)  # revealed: Unknown
 

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

@@ -75,6 +75,7 @@ class CanIndex(Protocol[S]):
     def __getitem__(self, index: int, /) -> S: ...
 
 class ExplicitlyImplements[T](CanIndex[T]): ...
+class SubProtocol[T](CanIndex[T], Protocol): ...
 
 def takes_in_list[T](x: list[T]) -> list[T]:
     return x
@@ -98,6 +99,18 @@ def deep_explicit(x: ExplicitlyImplements[str]) -> None:
 def deeper_explicit(x: ExplicitlyImplements[set[str]]) -> None:
     reveal_type(takes_in_protocol(x))  # revealed: set[str]
 
+def deep_subprotocol(x: SubProtocol[str]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: str
+
+def deeper_subprotocol(x: SubProtocol[set[str]]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: set[str]
+
+def itself(x: CanIndex[str]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: str
+
+def deep_itself(x: CanIndex[set[str]]) -> None:
+    reveal_type(takes_in_protocol(x))  # revealed: set[str]
+
 def takes_in_type[T](x: type[T]) -> type[T]:
     return x
 

crates/ty_python_semantic/resources/mdtest/implicit_type_aliases.md

@@ -1179,6 +1179,34 @@ def _(
     reveal_type(subclass_of_p)  # revealed: type[P]
 ```
 
+Using `type[]` with a union type alias distributes the `type[]` over the union elements:
+
+```py
+from typing import Union
+
+class C: ...
+class D: ...
+
+UnionAlias1 = C | D
+UnionAlias2 = Union[C, D]
+
+SubclassOfUnionAlias1 = type[UnionAlias1]
+SubclassOfUnionAlias2 = type[UnionAlias2]
+
+reveal_type(SubclassOfUnionAlias1)  # revealed: <special-form 'type[C | D]'>
+reveal_type(SubclassOfUnionAlias2)  # revealed: <special-form 'type[C | D]'>
+
+def _(
+    subclass_of_union_alias1: SubclassOfUnionAlias1,
+    subclass_of_union_alias2: SubclassOfUnionAlias2,
+):
+    reveal_type(subclass_of_union_alias1)  # revealed: type[C] | type[D]
+    reveal_type(subclass_of_union_alias1())  # revealed: C | D
+
+    reveal_type(subclass_of_union_alias2)  # revealed: type[C] | type[D]
+    reveal_type(subclass_of_union_alias2())  # revealed: C | D
+```
+
 Invalid uses result in diagnostics:
 
 ```py

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

@@ -76,3 +76,63 @@ def reveal_type(obj, /): ...
 ```py
 reveal_type(foo)  # revealed: Unknown
 ```
+
+## Builtins imported from custom project-level stubs
+
+The project can add or replace builtins with the `__builtins__.pyi` stub. They will take precedence
+over the typeshed ones.
+
+```py
+reveal_type(foo)  # revealed: int
+reveal_type(bar)  # revealed: str
+reveal_type(quux(1))  # revealed: int
+b = baz  # error: [unresolved-reference]
+
+reveal_type(ord(100))  # revealed: bool
+a = ord("a")  # error: [invalid-argument-type]
+
+bar = int(123)
+reveal_type(bar)  # revealed: int
+```
+
+`__builtins__.pyi`:
+
+```pyi
+foo: int = ...
+bar: str = ...
+
+def quux(value: int) -> int: ...
+
+unused: str = ...
+
+def ord(x: int) -> bool: ...
+```
+
+Builtins stubs are searched relative to the project root, not the file using them.
+
+`under/some/folder.py`:
+
+```py
+reveal_type(foo)  # revealed: int
+reveal_type(bar)  # revealed: str
+```
+
+## Assigning custom builtins
+
+```py
+import builtins
+
+builtins.foo = 123
+builtins.bar = 456  # error: [unresolved-attribute]
+builtins.baz = 789  # error: [invalid-assignment]
+builtins.chr = lambda x: str(x)  # error: [invalid-assignment]
+builtins.chr = 10
+```
+
+`__builtins__.pyi`:
+
+```pyi
+foo: int
+baz: str
+chr: int
+```

crates/ty_python_semantic/resources/mdtest/literal/f_string.md

@@ -24,6 +24,16 @@ string = "hello"
 reveal_type(f"{string!r}")  # revealed: str
 ```
 
+## Debug Specifier
+
+The `=` specifier causes the expression text and value to be included in the output:
+
+```py
+# f"{1=}" evaluates to "1=1", but we fall back to `str` for now
+reveal_type(f"{1=}")  # revealed: str
+reveal_type(f"value: {42=}")  # revealed: str
+```
+
 ## Format Specifiers
 
 ```py

crates/ty_python_semantic/resources/mdtest/named_tuple.md

@@ -266,10 +266,10 @@ class Person(NamedTuple):
     age: int | None = None
 
 reveal_type(Person._field_defaults)  # revealed: dict[str, Any]
-reveal_type(Person._fields)  # revealed: tuple[str, ...]
+reveal_type(Person._fields)  # revealed: tuple[Literal["name"], Literal["age"]]
 reveal_type(Person._make)  # revealed: bound method <class 'Person'>._make(iterable: Iterable[Any]) -> Person
 reveal_type(Person._asdict)  # revealed: def _asdict(self) -> dict[str, Any]
-reveal_type(Person._replace)  # revealed: def _replace(self, **kwargs: Any) -> Self@_replace
+reveal_type(Person._replace)  # revealed: (self: Self, *, name: str = ..., age: int | None = ...) -> Self
 
 reveal_type(Person._make(("Alice", 42)))  # revealed: Person
 
@@ -277,6 +277,10 @@ person = Person("Alice", 42)
 
 reveal_type(person._asdict())  # revealed: dict[str, Any]
 reveal_type(person._replace(name="Bob"))  # revealed: Person
+
+# Invalid keyword arguments are detected:
+# error: [unknown-argument] "Argument `invalid` does not match any known parameter"
+person._replace(invalid=42)
 ```
 
 When accessing them on child classes of generic `NamedTuple`s, the return type is specialized
@@ -343,7 +347,7 @@ satisfy:
 def expects_named_tuple(x: typing.NamedTuple):
     reveal_type(x)  # revealed: tuple[object, ...] & NamedTupleLike
     reveal_type(x._make)  # revealed: bound method type[NamedTupleLike]._make(iterable: Iterable[Any]) -> NamedTupleLike
-    reveal_type(x._replace)  # revealed: bound method NamedTupleLike._replace(**kwargs) -> NamedTupleLike
+    reveal_type(x._replace)  # revealed: bound method NamedTupleLike._replace(...) -> NamedTupleLike
     # revealed: Overload[(value: tuple[object, ...], /) -> tuple[object, ...], (value: tuple[_T@__add__, ...], /) -> tuple[object, ...]]
     reveal_type(x.__add__)
     reveal_type(x.__iter__)  # revealed: bound method tuple[object, ...].__iter__() -> Iterator[object]
@@ -355,8 +359,9 @@ def _(y: type[typing.NamedTuple]):
 def _(z: typing.NamedTuple[int]): ...
 ```
 
-Any instance of a `NamedTuple` class can therefore be passed for a function parameter that is
-annotated with `NamedTuple`:
+NamedTuples are assignable to `NamedTupleLike`. The `NamedTupleLike._replace` method is typed with
+`(*args, **kwargs)`, which type checkers treat as equivalent to `...` (per the typing spec), making
+all NamedTuple implementations automatically compatible:
 
 ```py
 from typing import NamedTuple, Protocol, Iterable, Any
@@ -368,12 +373,15 @@ class Point(NamedTuple):
 
 reveal_type(Point._make)  # revealed: bound method <class 'Point'>._make(iterable: Iterable[Any]) -> Point
 reveal_type(Point._asdict)  # revealed: def _asdict(self) -> dict[str, Any]
-reveal_type(Point._replace)  # revealed: def _replace(self, **kwargs: Any) -> Self@_replace
+reveal_type(Point._replace)  # revealed: (self: Self, *, x: int = ..., y: int = ...) -> Self
 
+# Point is assignable to NamedTuple.
 static_assert(is_assignable_to(Point, NamedTuple))
 
-expects_named_tuple(Point(x=42, y=56))  # fine
+# NamedTuple instances can be passed to functions expecting NamedTupleLike.
+expects_named_tuple(Point(x=42, y=56))
 
+# But plain tuples are not NamedTupleLike (they don't have _make, _asdict, _replace, etc.).
 # error: [invalid-argument-type] "Argument to function `expects_named_tuple` is incorrect: Expected `tuple[object, ...] & NamedTupleLike`, found `tuple[Literal[1], Literal[2]]`"
 expects_named_tuple((1, 2))
 ```

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

@@ -0,0 +1,95 @@
+# Narrowing for `callable()`
+
+## Basic narrowing
+
+The `callable()` builtin returns `TypeIs[Callable[..., object]]`, which narrows the type to the
+intersection with `Top[Callable[..., object]]`. The `Top[...]` wrapper indicates this is a fully
+static type representing the top materialization of a gradual callable.
+
+Since all callable types are subtypes of `Top[Callable[..., object]]`, intersections with `Top[...]`
+simplify to just the original callable type.
+
+```py
+from typing import Any, Callable
+
+def f(x: Callable[..., Any] | None):
+    if callable(x):
+        # The intersection simplifies because `(...) -> Any` is a subtype of
+        # `Top[(...) -> object]` - all callables are subtypes of the top materialization.
+        reveal_type(x)  # revealed: (...) -> Any
+    else:
+        # Since `(...) -> Any` is a subtype of `Top[(...) -> object]`, the intersection
+        # with the negation is empty (Never), leaving just None.
+        reveal_type(x)  # revealed: None
+```
+
+## Narrowing with other callable types
+
+```py
+from typing import Any, Callable
+
+def g(x: Callable[[int], str] | None):
+    if callable(x):
+        # All callables are subtypes of `Top[(...) -> object]`, so the intersection simplifies.
+        reveal_type(x)  # revealed: (int, /) -> str
+    else:
+        reveal_type(x)  # revealed: None
+
+def h(x: Callable[..., int] | None):
+    if callable(x):
+        reveal_type(x)  # revealed: (...) -> int
+    else:
+        reveal_type(x)  # revealed: None
+```
+
+## Narrowing from object
+
+```py
+from typing import Callable
+
+def f(x: object):
+    if callable(x):
+        reveal_type(x)  # revealed: Top[(...) -> object]
+    else:
+        reveal_type(x)  # revealed: ~Top[(...) -> object]
+```
+
+## Calling narrowed callables
+
+The narrowed type `Top[Callable[..., object]]` represents the set of all possible callable types
+(including, e.g., functions that take no arguments and functions that require arguments). While such
+objects *are* callable (they pass `callable()`), no specific set of arguments can be guaranteed to
+be valid.
+
+```py
+import typing as t
+
+def call_with_args(y: object, a: int, b: str) -> object:
+    if isinstance(y, t.Callable):
+        # error: [call-top-callable]
+        return y(a, b)
+    return None
+```
+
+## Assignability of narrowed callables
+
+A narrowed callable `Top[Callable[..., object]]` should be assignable to `Callable[..., Any]`. This
+is important for decorators and other patterns where we need to pass the narrowed callable to
+functions expecting gradual callables.
+
+```py
+from typing import Any, Callable, TypeVar
+from ty_extensions import static_assert, Top, is_assignable_to
+
+static_assert(is_assignable_to(Top[Callable[..., bool]], Callable[..., int]))
+
+F = TypeVar("F", bound=Callable[..., Any])
+
+def wrap(f: F) -> F:
+    return f
+
+def f(x: object):
+    if callable(x):
+        # x has type `Top[(...) -> object]`, which should be assignable to `Callable[..., Any]`
+        wrap(x)
+```

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

@@ -197,15 +197,86 @@ def _(t1: tuple[int | None, int | None], t2: tuple[int, int] | tuple[None, None]
 
     n = 0
     if t1[n] is not None:
-        # Non-literal subscript narrowing are currently not supported, as well as mypy, pyright
+        # Narrowing the individual element type with a non-literal subscript is not supported
         reveal_type(t1[0])  # revealed: int | None
         reveal_type(t1[n])  # revealed: int | None
         reveal_type(t1[1])  # revealed: int | None
 
+    # However, we can still discriminate between tuples in a union using a variable index:
+    if t2[n] is not None:
+        reveal_type(t2)  # revealed: tuple[int, int]
+
     if t2[0] is not None:
+        reveal_type(t2)  # revealed: tuple[int, int]
         reveal_type(t2[0])  # revealed: int
-        # TODO: should be int
-        reveal_type(t2[1])  # revealed: int | None
+        reveal_type(t2[1])  # revealed: int
+    else:
+        reveal_type(t2)  # revealed: tuple[None, None]
+        reveal_type(t2[0])  # revealed: None
+        reveal_type(t2[1])  # revealed: None
+
+    if t2[0] is None:
+        reveal_type(t2)  # revealed: tuple[None, None]
+    else:
+        reveal_type(t2)  # revealed: tuple[int, int]
+
+def _(t3: tuple[int, str] | tuple[None, None] | tuple[bool, bytes]):
+    # Narrow to tuples where first element is not None
+    if t3[0] is not None:
+        reveal_type(t3)  # revealed: tuple[int, str] | tuple[bool, bytes]
+
+    # Narrow to tuples where first element is None
+    if t3[0] is None:
+        reveal_type(t3)  # revealed: tuple[None, None]
+
+def _(t4: tuple[bool, int] | tuple[bool, str]):
+    # Both tuples have bool at index 0, which is not disjoint from True,
+    # so neither gets filtered out when checking `is True`
+    if t4[0] is True:
+        reveal_type(t4)  # revealed: tuple[bool, int] | tuple[bool, str]
+
+def _(t5: tuple[int, None] | tuple[None, int]):
+    # Narrow on second element (index 1)
+    if t5[1] is not None:
+        reveal_type(t5)  # revealed: tuple[None, int]
+    else:
+        reveal_type(t5)  # revealed: tuple[int, None]
+
+    # Negative index
+    if t5[-1] is None:
+        reveal_type(t5)  # revealed: tuple[int, None]
+
+def _(t6: tuple[int, ...] | tuple[None, None]):
+    # Variadic tuple at index 0 has element type `int` (not a union),
+    # so `tuple[None, None]` gets filtered out
+    if t6[0] is not None:
+        reveal_type(t6)  # revealed: tuple[int, ...]
+
+def _(t6b: tuple[int, ...] | tuple[None, ...]):
+    # Both variadic: `int` is disjoint from None, `None` is not disjoint from None
+    if t6b[0] is not None:
+        reveal_type(t6b)  # revealed: tuple[int, ...]
+    else:
+        reveal_type(t6b)  # revealed: tuple[None, ...]
+
+def _(t7: tuple[int, int] | tuple[None, None]):
+    # Index out of range for both tuples - no narrowing, but errors are emitted
+    # error: [index-out-of-bounds] "Index 5 is out of bounds for tuple `tuple[int, int]` with length 2"
+    # error: [index-out-of-bounds] "Index 5 is out of bounds for tuple `tuple[None, None]` with length 2"
+    if t7[5] is not None:
+        reveal_type(t7)  # revealed: tuple[int, int] | tuple[None, None]
+
+def _(t8: tuple[int, int, int] | tuple[None, None]):
+    # Index in range for first tuple but out of range for second
+    # error: [index-out-of-bounds] "Index 2 is out of bounds for tuple `tuple[None, None]` with length 2"
+    if t8[2] is not None:
+        reveal_type(t8)  # revealed: tuple[int, int, int] | tuple[None, None]
+
+def _(t9: tuple[int | None, str] | tuple[str, int]):
+    # When the element type is a union (like `int | None`), we can't filter
+    # out the tuple.
+    if t9[0] is not None:
+        reveal_type(t9)  # revealed: tuple[int | None, str] | tuple[str, int]
 ```
 
 ### String subscript

crates/ty_python_semantic/resources/mdtest/narrow/conditionals/eq.md

@@ -238,3 +238,20 @@ def _(s: LiteralString | None, t: LiteralString | Any):
         # TODO could be `Literal["foo"] | Any`
         reveal_type(t)  # revealed: LiteralString | Any
 ```
+
+## Narrowing with tuple types
+
+We assume that tuple subclasses don't override `tuple.__eq__`, which only returns True for other
+tuples. So they are excluded from the narrowed type when comparing to non-tuple values.
+
+```py
+from typing import Literal
+
+def _(x: Literal["a", "b"] | tuple[int, int]):
+    if x == "a":
+        # tuple type is excluded because it's disjoint from the string literal
+        reveal_type(x)  # revealed: Literal["a"]
+    else:
+        # tuple type remains in the else branch
+        reveal_type(x)  # revealed: Literal["b"] | tuple[int, int]
+```

crates/ty_python_semantic/resources/mdtest/narrow/conditionals/in.md

@@ -191,3 +191,20 @@ def test(x: Status | int):
     else:
         reveal_type(x)  # revealed: Literal[Status.REJECTED] | int
 ```
+
+## Union with tuple and `Literal`
+
+We assume that tuple subclasses don't override `tuple.__eq__`, which only returns True for other
+tuples. So they are excluded from the narrowed type when disjoint from the RHS values.
+
+```py
+from typing import Literal
+
+def test(x: Literal["none", "auto", "required"] | tuple[list[str], Literal["auto", "required"]]):
+    if x in ("auto", "required"):
+        # tuple type is excluded because it's disjoint from the string literals
+        reveal_type(x)  # revealed: Literal["auto", "required"]
+    else:
+        # tuple type remains in the else branch
+        reveal_type(x)  # revealed: Literal["none"] | tuple[list[str], Literal["auto", "required"]]
+```

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

@@ -213,8 +213,7 @@ def f(x: dict[str, int] | list[str], y: object):
         reveal_type(x)  # revealed: list[str]
 
     if isinstance(y, t.Callable):
-        # TODO: a better top-materialization for `Callable`s (https://github.com/astral-sh/ty/issues/1426)
-        reveal_type(y)  # revealed: () -> object
+        reveal_type(y)  # revealed: Top[(...) -> object]
 ```
 
 ## Class types