Zizmor

Revert "Only run the relevant test"
This reverts commit 82dc27f2680b8085280136848ffe2ee1d2952a4e.
2025-07-03 07:23:11 -05:00 · 2025-07-03 07:01:28 -05:00 · 2025-07-03 07:01:28 -05:00 · 2025-07-03 07:01:28 -05:00 · 2025-07-03 07:01:28 -05:00 · 2025-07-03 07:01:27 -05:00
376 changed files with 5247 additions and 20014 deletions
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -214,7 +214,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: |
          rustup component add clippy
@@ -234,17 +234,17 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@f3a27926ea13d7be3ee2f4cbb925883cf9442b56 # v2.56.7
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@f3a27926ea13d7be3ee2f4cbb925883cf9442b56 # v2.56.7
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
        with:
          tool: cargo-insta
      - name: ty mdtests (GitHub annotations)
@@ -292,17 +292,17 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@f3a27926ea13d7be3ee2f4cbb925883cf9442b56 # v2.56.7
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
        with:
          tool: cargo-nextest
      - name: "Install cargo insta"
-        uses: taiki-e/install-action@f3a27926ea13d7be3ee2f4cbb925883cf9442b56 # v2.56.7
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
        with:
          tool: cargo-insta
      - name: "Run tests"
@@ -321,14 +321,30 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - name: Setup Dev Drive
+        run: ${{ github.workspace }}/.github/workflows/setup-dev-drive.ps1
+
+      # actions/checkout does not let us clone into anywhere outside `github.workspace`, so we have to copy the clone
+      - name: Copy Git Repo to Dev Drive
+        env:
+          RUFF_WORKSPACE: ${{ env.RUFF_WORKSPACE }}
+        run: |
+          Copy-Item -Path "${{ github.workspace }}" -Destination "${env:RUFF_WORKSPACE}" -Recurse
+
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
+        with:
+          workspaces: ${{ env.RUFF_WORKSPACE }}
+
      - name: "Install Rust toolchain"
+        working-directory: ${{ env.RUFF_WORKSPACE }}
        run: rustup show
+
      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@f3a27926ea13d7be3ee2f4cbb925883cf9442b56 # v2.56.7
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
        with:
          tool: cargo-nextest
      - name: "Run tests"
+        working-directory: ${{ env.RUFF_WORKSPACE }}
        shell: bash
        env:
          NEXTEST_PROFILE: "ci"
@@ -348,7 +364,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
@@ -377,7 +393,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Install mold"
@@ -400,18 +416,27 @@ jobs:
        with:
          file: "Cargo.toml"
          field: "workspace.package.rust-version"
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        env:
          MSRV: ${{ steps.msrv.outputs.value }}
        run: rustup default "${MSRV}"
      - name: "Install mold"
        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
-      - name: "Build tests"
+      - name: "Install cargo nextest"
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
+        with:
+          tool: cargo-nextest
+      - name: "Install cargo insta"
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
+        with:
+          tool: cargo-insta
+      - name: "Run tests"
        shell: bash
        env:
+          NEXTEST_PROFILE: "ci"
          MSRV: ${{ steps.msrv.outputs.value }}
-        run: cargo "+${MSRV}" test --no-run --all-features
+        run: cargo "+${MSRV}" insta test --all-features --unreferenced reject --test-runner nextest

  cargo-fuzz-build:
    name: "cargo fuzz build"
@@ -423,7 +448,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
        with:
          workspaces: "fuzz -> target"
      - name: "Install Rust toolchain"
@@ -485,7 +510,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup component add rustfmt
      # Run all code generation scripts, and verify that the current output is
@@ -699,7 +724,7 @@ jobs:
        with:
          python-version: ${{ env.PYTHON_VERSION }}
          architecture: x64
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Prep README.md"
        run: python scripts/transform_readme.py --target pypi
      - name: "Build wheels"
@@ -723,7 +748,7 @@ jobs:
        with:
          persist-credentials: false
      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
        with:
          node-version: 22
@@ -756,7 +781,7 @@ jobs:
      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
        with:
          python-version: "3.13"
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Add SSH key"
        if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
        uses: webfactory/ssh-agent@a6f90b1f127823b31d4d4a8d96047790581349bd # v0.9.1
@@ -795,7 +820,7 @@ jobs:
      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
        with:
          persist-credentials: false
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: "Install Rust toolchain"
        run: rustup show
      - name: "Run checks"
@@ -865,7 +890,7 @@ jobs:
          persist-credentials: false
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
        with:
          node-version: 22
@@ -896,14 +921,14 @@ jobs:
        with:
          persist-credentials: false

-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1

      - name: "Install Rust toolchain"
        run: rustup show

      - name: "Install codspeed"
-        uses: taiki-e/install-action@f3a27926ea13d7be3ee2f4cbb925883cf9442b56 # v2.56.7
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
        with:
          tool: cargo-codspeed

@@ -929,14 +954,14 @@ jobs:
        with:
          persist-credentials: false

-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1

      - name: "Install Rust toolchain"
        run: rustup show

      - name: "Install codspeed"
-        uses: taiki-e/install-action@f3a27926ea13d7be3ee2f4cbb925883cf9442b56 # v2.56.7
+        uses: taiki-e/install-action@d12e869b89167df346dd0ff65da342d1fb1202fb # v2.53.2
        with:
          tool: cargo-codspeed

--- a/.github/workflows/daily_fuzz.yaml
+++ b/.github/workflows/daily_fuzz.yaml
@@ -39,7 +39,7 @@ jobs:
        run: rustup show
      - name: "Install mold"
        uses: rui314/setup-mold@85c79d00377f0d32cdbae595a46de6f7c2fa6599 # v1
-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
      - name: Build ruff
        # A debug build means the script runs slower once it gets started,
        # but this is outweighed by the fact that a release build takes *much* longer to compile in CI
--- a/.github/workflows/mypy_primer.yaml
+++ b/.github/workflows/mypy_primer.yaml
@@ -12,7 +12,6 @@ on:
      - ".github/workflows/mypy_primer.yaml"
      - ".github/workflows/mypy_primer_comment.yaml"
      - "Cargo.lock"
-      - "!**.md"

 concurrency:
  group: ${{ github.workflow }}-${{ github.ref_name }}-${{ github.event.pull_request.number || github.sha }}
@@ -40,7 +39,7 @@ jobs:
      - name: Install the latest version of uv
        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1

-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
        with:
          workspaces: "ruff"

@@ -50,12 +49,46 @@ jobs:
      - name: Run mypy_primer
        shell: bash
        env:
-          PRIMER_SELECTOR: crates/ty_python_semantic/resources/primer/good.txt
-          DIFF_FILE: mypy_primer.diff
+          TY_MEMORY_REPORT: mypy_primer
        run: |
          cd ruff
-          scripts/mypy_primer.sh
-          echo ${{ github.event.number }} > ../pr-number
+
+          echo "Enabling mypy primer specific configuration overloads (see .github/mypy-primer-ty.toml)"
+          mkdir -p ~/.config/ty
+          cp .github/mypy-primer-ty.toml ~/.config/ty/ty.toml
+
+          PRIMER_SELECTOR="$(paste -s -d'|' crates/ty_python_semantic/resources/primer/good.txt)"
+
+          echo "new commit"
+          git rev-list --format=%s --max-count=1 "$GITHUB_SHA"
+
+          MERGE_BASE="$(git merge-base "$GITHUB_SHA" "origin/$GITHUB_BASE_REF")"
+          git checkout -b base_commit "$MERGE_BASE"
+          echo "base commit"
+          git rev-list --format=%s --max-count=1 base_commit
+
+          cd ..
+
+          echo "Project selector: $PRIMER_SELECTOR"
+          # Allow the exit code to be 0 or 1, only fail for actual mypy_primer crashes/bugs
+          uvx \
+            --from="git+https://github.com/hauntsaninja/mypy_primer@e5f55447969d33ae3c7ccdb183e2a37101867270" \
+            mypy_primer \
+            --repo ruff \
+            --type-checker ty \
+            --old base_commit \
+            --new "$GITHUB_SHA" \
+            --project-selector "/($PRIMER_SELECTOR)\$" \
+            --output concise \
+            --debug > mypy_primer.diff || [ $? -eq 1 ]
+
+          # Output diff with ANSI color codes
+          cat mypy_primer.diff
+
+          # Remove ANSI color codes before uploading
+          sed -ie 's/\x1b\[[0-9;]*m//g' mypy_primer.diff
+
+          echo ${{ github.event.number }} > pr-number

      - name: Upload diff
        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
@@ -68,41 +101,3 @@ jobs:
        with:
          name: pr-number
          path: pr-number
-
-  memory_usage:
-    name: Run memory statistics
-    runs-on: depot-ubuntu-22.04-32
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-        with:
-          path: ruff
-          fetch-depth: 0
-          persist-credentials: false
-
-      - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1
-
-      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
-        with:
-          workspaces: "ruff"
-
-      - name: Install Rust toolchain
-        run: rustup show
-
-      - name: Run mypy_primer
-        shell: bash
-        env:
-          TY_MAX_PARALLELISM: 1 # for deterministic memory numbers
-          TY_MEMORY_REPORT: mypy_primer
-          PRIMER_SELECTOR: crates/ty_python_semantic/resources/primer/memory.txt
-          DIFF_FILE: mypy_primer_memory.diff
-        run: |
-          cd ruff
-          scripts/mypy_primer.sh
-
-      - name: Upload diff
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: mypy_primer_memory_diff
-          path: mypy_primer_memory.diff
--- a/.github/workflows/mypy_primer_comment.yaml
+++ b/.github/workflows/mypy_primer_comment.yaml
@@ -45,28 +45,15 @@ jobs:
          if_no_artifact_found: ignore
          allow_forks: true

-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
-        name: "Download mypy_primer memory results"
-        id: download-mypy_primer_memory_diff
-        if: steps.pr-number.outputs.pr-number
-        with:
-          name: mypy_primer_memory_diff
-          workflow: mypy_primer.yaml
-          pr: ${{ steps.pr-number.outputs.pr-number }}
-          path: pr/mypy_primer_memory_diff
-          workflow_conclusion: completed
-          if_no_artifact_found: ignore
-          allow_forks: true
-
      - name: Generate comment content
        id: generate-comment
-        if: ${{ steps.download-mypy_primer_diff.outputs.found_artifact == 'true' && steps.download-mypy_primer_memory_diff.outputs.found_artifact == 'true' }}
+        if: steps.download-mypy_primer_diff.outputs.found_artifact == 'true'
        run: |
          # Guard against malicious mypy_primer results that symlink to a secret
          # file on this runner
-          if [[ -L pr/mypy_primer_diff/mypy_primer.diff ]] || [[ -L pr/mypy_primer_memory_diff/mypy_primer_memory.diff ]]
+          if [[ -L pr/mypy_primer_diff/mypy_primer.diff ]]
          then
-              echo "Error: mypy_primer.diff and mypy_primer_memory.diff cannot be a symlink"
+              echo "Error: mypy_primer.diff cannot be a symlink"
              exit 1
          fi

@@ -87,18 +74,6 @@ jobs:
            echo 'No ecosystem changes detected ✅' >> comment.txt
          fi

-          if [ -s "pr/mypy_primer_memory_diff/mypy_primer_memory.diff" ]; then
-            echo '<details>' >> comment.txt
-            echo '<summary>Memory usage changes were detected when running on open source projects</summary>' >> comment.txt
-            echo '' >> comment.txt
-            echo '```diff' >> comment.txt
-            cat pr/mypy_primer_memory_diff/mypy_primer_memory.diff >> comment.txt
-            echo '```' >> comment.txt
-            echo '</details>' >> comment.txt
-          else
-            echo 'No memory usage changes detected ✅' >> comment.txt
-          fi
-
          echo 'comment<<EOF' >> "$GITHUB_OUTPUT"
          cat comment.txt >> "$GITHUB_OUTPUT"
          echo 'EOF' >> "$GITHUB_OUTPUT"
--- a/.github/workflows/publish-docs.yml
+++ b/.github/workflows/publish-docs.yml
@@ -68,7 +68,7 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup show

-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8

      - name: "Install Insiders dependencies"
        if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
--- a/.github/workflows/setup-dev-drive.ps1
+++ b/.github/workflows/setup-dev-drive.ps1
@@ -0,0 +1,93 @@
+# Configures a drive for testing in CI.
+#
+# When using standard GitHub Actions runners, a `D:` drive is present and has
+# similar or better performance characteristics than a ReFS dev drive. Sometimes
+# using a larger runner is still more performant (e.g., when running the test
+# suite) and we need to create a dev drive. This script automatically configures
+# the appropriate drive.
+#
+# When using GitHub Actions' "larger runners", the `D:` drive is not present and
+# we create a DevDrive mount on `C:`. This is purported to be more performant
+# than an ReFS drive, though we did not see a change when we switched over.
+#
+# When using Depot runners, the underling infrastructure is EC2, which does not
+# support Hyper-V. The `New-VHD` commandlet only works with Hyper-V, but we can
+# create a ReFS drive using `diskpart` and `format` directory. We cannot use a
+# DevDrive, as that also requires Hyper-V. The Depot runners use `D:` already,
+# so we must check if it's a Depot runner first, and we use `V:` as the target
+# instead.
+
+
+if ($env:DEPOT_RUNNER -eq "1") {
+    Write-Output "DEPOT_RUNNER detected, setting up custom dev drive..."
+
+    # Create VHD and configure drive using diskpart
+    $vhdPath = "C:\ruff_dev_drive.vhdx"
+    @"
+create vdisk file="$vhdPath" maximum=20480 type=expandable
+attach vdisk
+create partition primary
+active
+assign letter=V
+"@ | diskpart
+
+    # Format the drive as ReFS
+    format V: /fs:ReFS /q /y
+    $Drive = "V:"
+
+    Write-Output "Custom dev drive created at $Drive"
+} elseif (Test-Path "D:\") {
+	# Note `Get-PSDrive` is not sufficient because the drive letter is assigned.
+    Write-Output "Using existing drive at D:"
+    $Drive = "D:"
+} else {
+	# The size (20 GB) is chosen empirically to be large enough for our
+	# workflows; larger drives can take longer to set up.
+	$Volume = New-VHD -Path C:/ruff_dev_drive.vhdx -SizeBytes 20GB |
+						Mount-VHD -Passthru |
+						Initialize-Disk -Passthru |
+						New-Partition -AssignDriveLetter -UseMaximumSize |
+						Format-Volume -DevDrive -Confirm:$false -Force
+
+	$Drive = "$($Volume.DriveLetter):"
+
+	# Set the drive as trusted
+	# See https://learn.microsoft.com/en-us/windows/dev-drive/#how-do-i-designate-a-dev-drive-as-trusted
+	fsutil devdrv trust $Drive
+
+	# Disable antivirus filtering on dev drives
+	# See https://learn.microsoft.com/en-us/windows/dev-drive/#how-do-i-configure-additional-filters-on-dev-drive
+	fsutil devdrv enable /disallowAv
+
+	# Remount so the changes take effect
+	Dismount-VHD -Path C:/ruff_dev_drive.vhdx
+	Mount-VHD -Path C:/ruff_dev_drive.vhdx
+
+	# Show some debug information
+	Write-Output $Volume
+	fsutil devdrv query $Drive
+
+    Write-Output "Using Dev Drive at $Volume"
+}
+
+$Tmp = "$($Drive)\ruff-tmp"
+
+# Create the directory ahead of time in an attempt to avoid race-conditions
+New-Item $Tmp -ItemType Directory
+
+# Move Cargo to the dev drive
+New-Item -Path "$($Drive)/.cargo/bin" -ItemType Directory -Force
+if (Test-Path "C:/Users/runneradmin/.cargo") {
+    Copy-Item -Path "C:/Users/runneradmin/.cargo/*" -Destination "$($Drive)/.cargo/" -Recurse -Force
+}
+
+Write-Output `
+	"DEV_DRIVE=$($Drive)" `
+	"TMP=$($Tmp)" `
+	"TEMP=$($Tmp)" `
+	"UV_INTERNAL__TEST_DIR=$($Tmp)" `
+	"RUSTUP_HOME=$($Drive)/.rustup" `
+	"CARGO_HOME=$($Drive)/.cargo" `
+	"RUFF_WORKSPACE=$($Drive)/ruff" `
+	"PATH=$($Drive)/.cargo/bin;$env:PATH" `
+	>> $env:GITHUB_ENV
--- a/.github/workflows/ty-ecosystem-analyzer.yaml
+++ b/.github/workflows/ty-ecosystem-analyzer.yaml
@@ -17,7 +17,6 @@ env:
  RUSTUP_MAX_RETRIES: 10
  RUST_BACKTRACE: 1
  REF_NAME: ${{ github.ref_name }}
-  CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}

 jobs:
  ty-ecosystem-analyzer:
@@ -35,7 +34,7 @@ jobs:
      - name: Install the latest version of uv
        uses: astral-sh/setup-uv@bd01e18f51369d5a26f1651c3cb451d3417e3bba # v6.3.1

-      - uses: Swatinem/rust-cache@98c8021b550208e191a6a3145459bfc9fb29c4c0 # v2.8.0
+      - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
        with:
          workspaces: "ruff"

@@ -64,75 +63,32 @@ jobs:

          cd ..

-          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@f0eec0e549684d8e1d7b8bc3e351202124b63bda"
+          uv tool install "git+https://github.com/astral-sh/ecosystem-analyzer@9c34dc514ee9aef6735db1dfebb80f63acbc3440"

          ecosystem-analyzer \
            --repository ruff \
-            diff \
-            --projects-old ruff/projects_old.txt \
-            --projects-new ruff/projects_new.txt \
-            --old old_commit \
-            --new new_commit \
-            --output-old diagnostics-old.json \
-            --output-new diagnostics-new.json
+            analyze \
+            --projects ruff/projects_old.txt \
+            --commit old_commit \
+            --output diagnostics_old.json

-          mkdir dist
+          ecosystem-analyzer \
+            --repository ruff \
+            analyze \
+            --projects ruff/projects_new.txt \
+            --commit new_commit \
+            --output diagnostics_new.json

          ecosystem-analyzer \
            generate-diff \
-            diagnostics-old.json \
-            diagnostics-new.json \
+            diagnostics_old.json \
+            diagnostics_new.json \
            --old-name "main (merge base)" \
            --new-name "$REF_NAME" \
-            --output-html dist/diff.html
+            --output-html diff.html

-          ecosystem-analyzer \
-            generate-diff-statistics \
-            diagnostics-old.json \
-            diagnostics-new.json \
-            --old-name "main (merge base)" \
-            --new-name "$REF_NAME" \
-            --output diff-statistics.md
-
-          echo '## `ecosystem-analyzer` results' > comment.md
-          echo >> comment.md
-          cat diff-statistics.md >> comment.md
-
-          cat diff-statistics.md >> "$GITHUB_STEP_SUMMARY"
-
-          echo ${{ github.event.number }} > pr-number
-
-      - name: "Deploy to Cloudflare Pages"
-        if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        id: deploy
-        uses: cloudflare/wrangler-action@da0e0dfe58b7a431659754fdf3f186c529afbe65 # v3.14.1
-        with:
-          apiToken: ${{ secrets.CF_API_TOKEN }}
-          accountId: ${{ secrets.CF_ACCOUNT_ID }}
-          command: pages deploy dist --project-name=ty-ecosystem --branch ${{ github.head_ref }} --commit-hash ${GITHUB_SHA}
-
-      - name: "Append deployment URL"
-        if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        env:
-          DEPLOYMENT_URL: ${{ steps.deploy.outputs.pages-deployment-alias-url }}
-        run: |
-          echo >> comment.md
-          echo "**[Full report with detailed diff]($DEPLOYMENT_URL/diff)**" >> comment.md
-
-      - name: Upload comment
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: comment.md
-          path: comment.md
-
-      - name: Upload pr-number
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
-        with:
-          name: pr-number
-          path: pr-number
-
-      - name: Upload diagnostics diff
+      - name: Upload HTML diff report
        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
        with:
          name: diff.html
-          path: dist/diff.html
+          path: diff.html
--- a/.github/workflows/ty-ecosystem-analyzer_comment.yaml
+++ b/.github/workflows/ty-ecosystem-analyzer_comment.yaml
@@ -1,85 +0,0 @@
-name: PR comment (ty ecosystem-analyzer)
-
-on: # zizmor: ignore[dangerous-triggers]
-  workflow_run:
-    workflows: [ty ecosystem-analyzer]
-    types: [completed]
-  workflow_dispatch:
-    inputs:
-      workflow_run_id:
-        description: The ty ecosystem-analyzer workflow that triggers the workflow run
-        required: true
-
-jobs:
-  comment:
-    runs-on: ubuntu-24.04
-    permissions:
-      pull-requests: write
-    steps:
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
-        name: Download PR number
-        with:
-          name: pr-number
-          run_id: ${{ github.event.workflow_run.id ||  github.event.inputs.workflow_run_id }}
-          if_no_artifact_found: ignore
-          allow_forks: true
-
-      - name: Parse pull request number
-        id: pr-number
-        run: |
-          if [[ -f pr-number ]]
-          then
-            echo "pr-number=$(<pr-number)" >> "$GITHUB_OUTPUT"
-          fi
-
-      - uses: dawidd6/action-download-artifact@20319c5641d495c8a52e688b7dc5fada6c3a9fbc # v8
-        name: "Download comment.md"
-        id: download-comment
-        if: steps.pr-number.outputs.pr-number
-        with:
-          name: comment.md
-          workflow: ty-ecosystem-analyzer.yaml
-          pr: ${{ steps.pr-number.outputs.pr-number }}
-          path: pr/comment
-          workflow_conclusion: completed
-          if_no_artifact_found: ignore
-          allow_forks: true
-
-      - name: Generate comment content
-        id: generate-comment
-        if: ${{ steps.download-comment.outputs.found_artifact == 'true' }}
-        run: |
-          # Guard against malicious ty ecosystem-analyzer results that symlink to a secret
-          # file on this runner
-          if [[ -L pr/comment/comment.md ]]
-          then
-              echo "Error: comment.md cannot be a symlink"
-              exit 1
-          fi
-
-          # Note: this identifier is used to find the comment to update on subsequent runs
-          echo '<!-- generated-comment ty ecosystem-analyzer -->' > comment.md
-          echo >> comment.md
-          cat pr/comment/comment.md >> comment.md
-
-          echo 'comment<<EOF' >> "$GITHUB_OUTPUT"
-          cat comment.md >> "$GITHUB_OUTPUT"
-          echo 'EOF' >> "$GITHUB_OUTPUT"
-
-      - name: Find existing comment
-        uses: peter-evans/find-comment@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3.1.0
-        if: steps.generate-comment.outcome == 'success'
-        id: find-comment
-        with:
-          issue-number: ${{ steps.pr-number.outputs.pr-number }}
-          comment-author: "github-actions[bot]"
-          body-includes: "<!-- generated-comment ty ecosystem-analyzer -->"
-
-      - name: Create or update comment
-        if: steps.find-comment.outcome == 'success'
-        uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4
-        with:
-          comment-id: ${{ steps.find-comment.outputs.comment-id }}
-          issue-number: ${{ steps.pr-number.outputs.pr-number }}
-          body-path: comment.md
-          edit-mode: replace
--- a/.github/zizmor.yml
+++ b/.github/zizmor.yml
@@ -10,7 +10,6 @@ rules:
    ignore:
      - build-docker.yml
      - publish-playground.yml
-      - ty-ecosystem-analyzer.yaml
  excessive-permissions:
    # it's hard to test what the impact of removing these ignores would be
    # without actually running the release workflow...
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -6,7 +6,7 @@ exclude: |
    crates/ty_vendored/vendor/.*|
    crates/ty_project/resources/.*|
    crates/ty_python_semantic/resources/corpus/.*|
-    crates/ty/docs/(configuration|rules|cli|environment).md|
+    crates/ty/docs/(configuration|rules|cli).md|
    crates/ruff_benchmark/resources/.*|
    crates/ruff_linter/resources/.*|
    crates/ruff_linter/src/rules/.*/snapshots/.*|
@@ -67,7 +67,7 @@ repos:
          - black==25.1.0

  - repo: https://github.com/crate-ci/typos
-    rev: v1.34.0
+    rev: v1.33.1
    hooks:
      - id: typos

@@ -81,7 +81,7 @@ repos:
        pass_filenames: false # This makes it a lot faster

  - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.12.2
+    rev: v0.12.1
    hooks:
      - id: ruff-format
      - id: ruff
@@ -99,12 +99,12 @@ repos:
  # zizmor detects security vulnerabilities in GitHub Actions workflows.
  # Additional configuration for the tool is found in `.github/zizmor.yml`
  - repo: https://github.com/woodruffw/zizmor-pre-commit
-    rev: v1.11.0
+    rev: v1.10.0
    hooks:
      - id: zizmor

  - repo: https://github.com/python-jsonschema/check-jsonschema
-    rev: 0.33.2
+    rev: 0.33.1
    hooks:
      - id: check-github-workflows

--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,89 +1,5 @@
 # Changelog

-## 0.12.3
-
-### Preview features
-
- \[`flake8-bugbear`\] Support non-context-manager calls in `B017` ([#19063](https://github.com/astral-sh/ruff/pull/19063))
- \[`flake8-use-pathlib`\] Add autofixes for `PTH100`, `PTH106`, `PTH107`, `PTH108`, `PTH110`, `PTH111`, `PTH112`, `PTH113`, `PTH114`, `PTH115`, `PTH117`, `PTH119`, `PTH120` ([#19213](https://github.com/astral-sh/ruff/pull/19213))
- \[`flake8-use-pathlib`\] Add autofixes for `PTH203`, `PTH204`, `PTH205` ([#18922](https://github.com/astral-sh/ruff/pull/18922))
-
-### Bug fixes
-
- \[`flake8-return`\] Fix false-positive for variables used inside nested functions in `RET504` ([#18433](https://github.com/astral-sh/ruff/pull/18433))
- Treat form feed as valid whitespace before a line continuation ([#19220](https://github.com/astral-sh/ruff/pull/19220))
- \[`flake8-type-checking`\] Fix syntax error introduced by fix (`TC008`) ([#19150](https://github.com/astral-sh/ruff/pull/19150))
- \[`pyupgrade`\] Keyword arguments in `super` should suppress the `UP008` fix ([#19131](https://github.com/astral-sh/ruff/pull/19131))
-
-### Documentation
-
- \[`flake8-pyi`\] Make example error out-of-the-box (`PYI007`, `PYI008`) ([#19103](https://github.com/astral-sh/ruff/pull/19103))
- \[`flake8-simplify`\] Make example error out-of-the-box (`SIM116`) ([#19111](https://github.com/astral-sh/ruff/pull/19111))
- \[`flake8-type-checking`\] Make example error out-of-the-box (`TC001`) ([#19151](https://github.com/astral-sh/ruff/pull/19151))
- \[`flake8-use-pathlib`\] Make example error out-of-the-box (`PTH210`) ([#19189](https://github.com/astral-sh/ruff/pull/19189))
- \[`pycodestyle`\] Make example error out-of-the-box (`E272`) ([#19191](https://github.com/astral-sh/ruff/pull/19191))
- \[`pycodestyle`\] Make example not raise unnecessary `SyntaxError` (`E114`) ([#19190](https://github.com/astral-sh/ruff/pull/19190))
- \[`pydoclint`\] Make example error out-of-the-box (`DOC501`) ([#19218](https://github.com/astral-sh/ruff/pull/19218))
- \[`pylint`, `pyupgrade`\] Fix syntax errors in examples (`PLW1501`, `UP028`) ([#19127](https://github.com/astral-sh/ruff/pull/19127))
- \[`pylint`\] Update `missing-maxsplit-arg` docs and error to suggest proper usage (`PLC0207`) ([#18949](https://github.com/astral-sh/ruff/pull/18949))
- \[`flake8-bandit`\] Make example error out-of-the-box (`S412`) ([#19241](https://github.com/astral-sh/ruff/pull/19241))
-
-## 0.12.2
-
-### Preview features
-
- \[`flake8-pyi`\] Expand `Optional[A]` to `A | None` (`PYI016`) ([#18572](https://github.com/astral-sh/ruff/pull/18572))
- \[`pyupgrade`\] Mark `UP008` fix safe if no comments are in range ([#18683](https://github.com/astral-sh/ruff/pull/18683))
-
-### Bug fixes
-
- \[`flake8-comprehensions`\] Fix `C420` to prepend whitespace when needed ([#18616](https://github.com/astral-sh/ruff/pull/18616))
- \[`perflint`\] Fix `PERF403` panic on attribute or subscription loop variable ([#19042](https://github.com/astral-sh/ruff/pull/19042))
- \[`pydocstyle`\] Fix `D413` infinite loop for parenthesized docstring ([#18930](https://github.com/astral-sh/ruff/pull/18930))
- \[`pylint`\] Fix `PLW0108` autofix introducing a syntax error when the lambda's body contains an assignment expression ([#18678](https://github.com/astral-sh/ruff/pull/18678))
- \[`refurb`\] Fix false positive on empty tuples (`FURB168`) ([#19058](https://github.com/astral-sh/ruff/pull/19058))
- \[`ruff`\] Allow more `field` calls from `attrs` (`RUF009`) ([#19021](https://github.com/astral-sh/ruff/pull/19021))
- \[`ruff`\] Fix syntax error introduced for an empty string followed by a u-prefixed string (`UP025`) ([#18899](https://github.com/astral-sh/ruff/pull/18899))
-
-### Rule changes
-
- \[`flake8-executable`\] Allow `uvx` in shebang line (`EXE003`) ([#18967](https://github.com/astral-sh/ruff/pull/18967))
- \[`pandas`\] Avoid flagging `PD002` if `pandas` is not imported ([#18963](https://github.com/astral-sh/ruff/pull/18963))
- \[`pyupgrade`\] Avoid PEP-604 unions with `typing.NamedTuple` (`UP007`, `UP045`) ([#18682](https://github.com/astral-sh/ruff/pull/18682))
-
-### Documentation
-
- Document link between `import-outside-top-level (PLC0415)` and `lint.flake8-tidy-imports.banned-module-level-imports` ([#18733](https://github.com/astral-sh/ruff/pull/18733))
- Fix description of the `format.skip-magic-trailing-comma` example ([#19095](https://github.com/astral-sh/ruff/pull/19095))
- \[`airflow`\] Make `AIR302` example error out-of-the-box ([#18988](https://github.com/astral-sh/ruff/pull/18988))
- \[`airflow`\] Make `AIR312` example error out-of-the-box ([#18989](https://github.com/astral-sh/ruff/pull/18989))
- \[`flake8-annotations`\] Make `ANN401` example error out-of-the-box ([#18974](https://github.com/astral-sh/ruff/pull/18974))
- \[`flake8-async`\] Make `ASYNC100` example error out-of-the-box ([#18993](https://github.com/astral-sh/ruff/pull/18993))
- \[`flake8-async`\] Make `ASYNC105` example error out-of-the-box ([#19002](https://github.com/astral-sh/ruff/pull/19002))
- \[`flake8-async`\] Make `ASYNC110` example error out-of-the-box ([#18975](https://github.com/astral-sh/ruff/pull/18975))
- \[`flake8-async`\] Make `ASYNC210` example error out-of-the-box ([#18977](https://github.com/astral-sh/ruff/pull/18977))
- \[`flake8-async`\] Make `ASYNC220`, `ASYNC221`, and `ASYNC222` examples error out-of-the-box ([#18978](https://github.com/astral-sh/ruff/pull/18978))
- \[`flake8-async`\] Make `ASYNC251` example error out-of-the-box ([#18990](https://github.com/astral-sh/ruff/pull/18990))
- \[`flake8-bandit`\] Make `S201` example error out-of-the-box ([#19017](https://github.com/astral-sh/ruff/pull/19017))
- \[`flake8-bandit`\] Make `S604` and `S609` examples error out-of-the-box ([#19049](https://github.com/astral-sh/ruff/pull/19049))
- \[`flake8-bugbear`\] Make `B028` example error out-of-the-box ([#19054](https://github.com/astral-sh/ruff/pull/19054))
- \[`flake8-bugbear`\] Make `B911` example error out-of-the-box ([#19051](https://github.com/astral-sh/ruff/pull/19051))
- \[`flake8-datetimez`\] Make `DTZ011` example error out-of-the-box ([#19055](https://github.com/astral-sh/ruff/pull/19055))
- \[`flake8-datetimez`\] Make `DTZ901` example error out-of-the-box ([#19056](https://github.com/astral-sh/ruff/pull/19056))
- \[`flake8-pyi`\] Make `PYI032` example error out-of-the-box ([#19061](https://github.com/astral-sh/ruff/pull/19061))
- \[`flake8-pyi`\] Make example error out-of-the-box (`PYI014`, `PYI015`) ([#19097](https://github.com/astral-sh/ruff/pull/19097))
- \[`flake8-pyi`\] Make example error out-of-the-box (`PYI042`) ([#19101](https://github.com/astral-sh/ruff/pull/19101))
- \[`flake8-pyi`\] Make example error out-of-the-box (`PYI059`) ([#19080](https://github.com/astral-sh/ruff/pull/19080))
- \[`flake8-pyi`\] Make example error out-of-the-box (`PYI062`) ([#19079](https://github.com/astral-sh/ruff/pull/19079))
- \[`flake8-pytest-style`\] Make example error out-of-the-box (`PT023`) ([#19104](https://github.com/astral-sh/ruff/pull/19104))
- \[`flake8-pytest-style`\] Make example error out-of-the-box (`PT030`) ([#19105](https://github.com/astral-sh/ruff/pull/19105))
- \[`flake8-quotes`\] Make example error out-of-the-box (`Q003`) ([#19106](https://github.com/astral-sh/ruff/pull/19106))
- \[`flake8-simplify`\] Make example error out-of-the-box (`SIM110`) ([#19113](https://github.com/astral-sh/ruff/pull/19113))
- \[`flake8-simplify`\] Make example error out-of-the-box (`SIM113`) ([#19109](https://github.com/astral-sh/ruff/pull/19109))
- \[`flake8-simplify`\] Make example error out-of-the-box (`SIM401`) ([#19110](https://github.com/astral-sh/ruff/pull/19110))
- \[`pyflakes`\] Fix backslash in docs (`F621`) ([#19098](https://github.com/astral-sh/ruff/pull/19098))
- \[`pylint`\] Fix `PLC0415` example ([#18970](https://github.com/astral-sh/ruff/pull/18970))
-
 ## 0.12.1

 ### Preview features
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -591,7 +591,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "117725a109d387c937a1533ce01b450cbde6b88abceea8473c4d7a85853cda3c"
 dependencies = [
 "lazy_static",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -600,7 +600,7 @@ version = "3.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fde0e0ec90c9dfb3b4b1a0891a7dcd0e2bffde2f7efed5fe7c9bb00e5bfb915e"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -629,24 +629,12 @@ name = "console"
 version = "0.15.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "054ccb5b10f9f2cbf51eb355ca1d05c2d279ce1804688d0db74b4733a5aeafd8"
-dependencies = [
- "encode_unicode",
- "libc",
- "once_cell",
- "windows-sys 0.59.0",
-]
-
-[[package]]
-name = "console"
-version = "0.16.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2e09ced7ebbccb63b4c65413d821f2e00ce54c5ca4514ddc6b3c892fdbcbc69d"
 dependencies = [
 "encode_unicode",
 "libc",
 "once_cell",
 "unicode-width 0.2.1",
- "windows-sys 0.60.2",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -680,6 +668,11 @@ name = "countme"
 version = "3.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7704b5fdd17b18ae31c4c1da5a2e0305a2bf17b5249300a9ee9ed7b72114c636"
+dependencies = [
+ "dashmap 5.5.3",
+ "once_cell",
+ "rustc-hash 1.1.0",
+]

 [[package]]
 name = "cpufeatures"
@@ -847,6 +840,19 @@ dependencies = [
 "syn",
 ]

+[[package]]
+name = "dashmap"
+version = "5.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "978747c1d849a7d2ee5e8adc0159961c48fb7e5db2f06af6723b80123bb53856"
+dependencies = [
+ "cfg-if",
+ "hashbrown 0.14.5",
+ "lock_api",
+ "once_cell",
+ "parking_lot_core",
+]
+
 [[package]]
 name = "dashmap"
 version = "6.1.0"
@@ -1013,7 +1019,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cea14ef9355e3beab063703aa9dab15afd25f0667c341310c1e5274bb1d0da18"
 dependencies = [
 "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -1475,14 +1481,14 @@ dependencies = [

 [[package]]
 name = "indicatif"
-version = "0.18.0"
+version = "0.17.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "70a646d946d06bedbbc4cac4c218acf4bbf2d87757a784857025f4d447e4e1cd"
+checksum = "183b3088984b400f4cfac3620d5e076c84da5364016b4f49473de574b2586235"
 dependencies = [
- "console 0.16.0",
+ "console",
+ "number_prefix",
 "portable-atomic",
 "unicode-width 0.2.1",
- "unit-prefix",
 "vt100",
 "web-time",
 ]
@@ -1519,7 +1525,7 @@ version = "1.43.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "154934ea70c58054b556dd430b99a98c2a7ff5309ac9891597e339b5c28f4371"
 dependencies = [
- "console 0.15.11",
+ "console",
 "globset",
 "once_cell",
 "pest",
@@ -1586,7 +1592,7 @@ checksum = "e04d7f318608d35d4b61ddd75cbdaee86b023ebe2bd5a66ee0915f0bf93095a9"
 dependencies = [
 "hermit-abi 0.5.1",
 "libc",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -1650,7 +1656,7 @@ dependencies = [
 "portable-atomic",
 "portable-atomic-util",
 "serde",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -2019,11 +2025,12 @@ checksum = "61807f77802ff30975e01f4f071c8ba10c022052f98b3294119f3e615d13e5be"

 [[package]]
 name = "notify"
-version = "8.1.0"
+version = "8.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3163f59cd3fa0e9ef8c32f242966a7b9994fd7378366099593e0e73077cd8c97"
+checksum = "2fee8403b3d66ac7b26aee6e40a897d85dc5ce26f44da36b8b73e987cc52e943"
 dependencies = [
 "bitflags 2.9.1",
+ "filetime",
 "fsevent-sys",
 "inotify",
 "kqueue",
@@ -2032,7 +2039,7 @@ dependencies = [
 "mio",
 "notify-types",
 "walkdir",
- "windows-sys 0.60.2",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -2070,6 +2077,12 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "number_prefix"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "830b246a0e5f20af87141b25c173cd1b609bd7779a4617d6ec582abaf90870f3"
+
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -2153,7 +2166,7 @@ dependencies = [
 "libc",
 "redox_syscall",
 "smallvec",
- "windows-targets 0.52.6",
+ "windows-targets",
 ]

 [[package]]
@@ -2244,7 +2257,7 @@ dependencies = [
 "once_cell",
 "pep440_rs",
 "regex",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "serde",
 "smallvec",
 "thiserror 1.0.69",
@@ -2711,7 +2724,7 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.1"
 dependencies = [
 "anyhow",
 "argfile",
@@ -2754,7 +2767,7 @@ dependencies = [
 "ruff_source_file",
 "ruff_text_size",
 "ruff_workspace",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "serde",
 "serde_json",
 "shellexpand",
@@ -2800,7 +2813,7 @@ dependencies = [
 "ruff_python_formatter",
 "ruff_python_parser",
 "ruff_python_trivia",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "serde",
 "serde_json",
 "tikv-jemallocator",
@@ -2829,7 +2842,7 @@ dependencies = [
 "arc-swap",
 "camino",
 "countme",
- "dashmap",
+ "dashmap 6.1.0",
 "dunce",
 "etcetera",
 "filetime",
@@ -2841,23 +2854,20 @@ dependencies = [
 "path-slash",
 "ruff_annotate_snippets",
 "ruff_cache",
- "ruff_diagnostics",
 "ruff_notebook",
 "ruff_python_ast",
 "ruff_python_parser",
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa",
 "schemars",
 "serde",
- "serde_json",
 "tempfile",
 "thiserror 2.0.12",
 "tracing",
 "tracing-subscriber",
- "ty_static",
 "web-time",
 "zip",
 ]
@@ -2901,7 +2911,6 @@ dependencies = [
 "tracing-subscriber",
 "ty",
 "ty_project",
- "ty_static",
 "url",
 ]

@@ -2909,7 +2918,6 @@ dependencies = [
 name = "ruff_diagnostics"
 version = "0.0.0"
 dependencies = [
- "get-size2",
 "is-macro",
 "ruff_text_size",
 "serde",
@@ -2923,7 +2931,7 @@ dependencies = [
 "ruff_cache",
 "ruff_macros",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "schemars",
 "serde",
 "static_assertions",
@@ -2962,7 +2970,7 @@ dependencies = [

 [[package]]
 name = "ruff_linter"
-version = "0.12.3"
+version = "0.12.1"
 dependencies = [
 "aho-corasick",
 "anyhow",
@@ -3005,7 +3013,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "schemars",
 "serde",
 "serde_json",
@@ -3077,7 +3085,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa",
 "schemars",
 "serde",
@@ -3127,7 +3135,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa",
 "schemars",
 "serde",
@@ -3176,7 +3184,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "serde",
 "serde_json",
 "static_assertions",
@@ -3200,7 +3208,7 @@ dependencies = [
 "ruff_python_parser",
 "ruff_python_stdlib",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "schemars",
 "serde",
 "smallvec",
@@ -3248,7 +3256,6 @@ dependencies = [
 "lsp-server",
 "lsp-types",
 "regex",
- "ruff_db",
 "ruff_diagnostics",
 "ruff_formatter",
 "ruff_linter",
@@ -3261,7 +3268,7 @@ dependencies = [
 "ruff_source_file",
 "ruff_text_size",
 "ruff_workspace",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "serde",
 "serde_json",
 "shellexpand",
@@ -3295,7 +3302,7 @@ dependencies = [

 [[package]]
 name = "ruff_wasm"
-version = "0.12.3"
+version = "0.12.1"
 dependencies = [
 "console_error_panic_hook",
 "console_log",
@@ -3350,7 +3357,7 @@ dependencies = [
 "ruff_python_semantic",
 "ruff_python_stdlib",
 "ruff_source_file",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "schemars",
 "serde",
 "shellexpand",
@@ -3369,6 +3376,12 @@ dependencies = [
 "serde_derive",
 ]

+[[package]]
+name = "rustc-hash"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
+
 [[package]]
 name = "rustc-hash"
 version = "2.1.1"
@@ -3391,7 +3404,7 @@ dependencies = [
 "errno",
 "libc",
 "linux-raw-sys",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -3423,7 +3436,7 @@ dependencies = [
 "parking_lot",
 "portable-atomic",
 "rayon",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa-macro-rules",
 "salsa-macros",
 "smallvec",
@@ -3587,9 +3600,9 @@ dependencies = [

 [[package]]
 name = "serde_with"
-version = "3.14.0"
+version = "3.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2c45cd61fefa9db6f254525d46e392b852e0e61d9a1fd36e5bd183450a556d5"
+checksum = "d6b6f7f2fcb69f747921f79f3926bd1e203fce4fef62c268dd3abfb6d86029aa"
 dependencies = [
 "serde",
 "serde_derive",
@@ -3598,9 +3611,9 @@ dependencies = [

 [[package]]
 name = "serde_with_macros"
-version = "3.14.0"
+version = "3.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "de90945e6565ce0d9a25098082ed4ee4002e047cb59892c318d66821e14bb30f"
+checksum = "8d00caa5193a3c8362ac2b73be6b9e768aa5a4b2f721d8f4b339600c3cb51f8e"
 dependencies = [
 "darling",
 "proc-macro2",
@@ -3781,7 +3794,7 @@ dependencies = [
 "getrandom 0.3.3",
 "once_cell",
 "rustix",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -4040,9 +4053,9 @@ dependencies = [

 [[package]]
 name = "tracing-core"
-version = "0.1.34"
+version = "0.1.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9d12581f227e93f094d3af2ae690a574abb8a2b9b7a96e7cfe9647b2b617678"
+checksum = "e672c95779cf947c5311f83787af4fa8fffd12fb27e4993211a84bdfd9610f9c"
 dependencies = [
 "once_cell",
 "valuable",
@@ -4061,9 +4074,9 @@ dependencies = [

 [[package]]
 name = "tracing-indicatif"
-version = "0.3.11"
+version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c714cc8fc46db04fcfddbd274c6ef59bebb1b435155984e7c6e89c3ce66f200"
+checksum = "8201ca430e0cd893ef978226fd3516c06d9c494181c8bf4e5b32e30ed4b40aa1"
 dependencies = [
 "indicatif",
 "tracing",
@@ -4121,6 +4134,7 @@ dependencies = [
 "clap",
 "clap_complete_command",
 "colored 3.0.0",
+ "countme",
 "crossbeam",
 "ctrlc",
 "dunce",
@@ -4143,7 +4157,6 @@ dependencies = [
 "ty_project",
 "ty_python_semantic",
 "ty_server",
- "ty_static",
 "wild",
 ]

@@ -4151,16 +4164,12 @@ dependencies = [
 name = "ty_ide"
 version = "0.0.0"
 dependencies = [
- "bitflags 2.9.1",
 "insta",
- "regex",
 "ruff_db",
 "ruff_python_ast",
 "ruff_python_parser",
- "ruff_python_trivia",
- "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa",
 "smallvec",
 "tracing",
@@ -4192,7 +4201,7 @@ dependencies = [
 "ruff_python_ast",
 "ruff_python_formatter",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa",
 "schemars",
 "serde",
@@ -4213,6 +4222,7 @@ dependencies = [
 "camino",
 "colored 3.0.0",
 "compact_str",
+ "countme",
 "dir-test",
 "drop_bomb",
 "get-size2",
@@ -4236,7 +4246,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa",
 "schemars",
 "serde",
@@ -4249,7 +4259,6 @@ dependencies = [
 "thiserror 2.0.12",
 "tracing",
 "ty_python_semantic",
- "ty_static",
 "ty_test",
 "ty_vendored",
 ]
@@ -4268,12 +4277,11 @@ dependencies = [
 "ruff_notebook",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "salsa",
 "serde",
 "serde_json",
 "shellexpand",
- "thiserror 2.0.12",
 "tracing",
 "tracing-subscriber",
 "ty_ide",
@@ -4282,13 +4290,6 @@ dependencies = [
 "ty_vendored",
 ]

-[[package]]
-name = "ty_static"
-version = "0.0.1"
-dependencies = [
- "ruff_macros",
-]
-
 [[package]]
 name = "ty_test"
 version = "0.0.0"
@@ -4307,7 +4308,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash",
+ "rustc-hash 2.1.1",
 "rustc-stable-hash",
 "salsa",
 "serde",
@@ -4317,7 +4318,6 @@ dependencies = [
 "toml",
 "tracing",
 "ty_python_semantic",
- "ty_static",
 "ty_vendored",
 ]

@@ -4470,12 +4470,6 @@ dependencies = [
 "rand 0.8.5",
 ]

-[[package]]
-name = "unit-prefix"
-version = "0.5.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "323402cff2dd658f39ca17c789b502021b3f18707c91cdf22e3838e1b4023817"
-
 [[package]]
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 version = "0.1.0"
@@ -4808,7 +4802,7 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]

 [[package]]
@@ -4882,7 +4876,7 @@ version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
 dependencies = [
- "windows-targets 0.52.6",
+ "windows-targets",
 ]

 [[package]]
@@ -4891,16 +4885,7 @@ version = "0.59.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
 dependencies = [
- "windows-targets 0.52.6",
-]
-
-[[package]]
-name = "windows-sys"
-version = "0.60.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
-dependencies = [
- "windows-targets 0.53.2",
+ "windows-targets",
 ]

 [[package]]
@@ -4909,30 +4894,14 @@ version = "0.52.6"
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 checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
 dependencies = [
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- "windows_aarch64_msvc 0.52.6",
- "windows_i686_gnu 0.52.6",
- "windows_i686_gnullvm 0.52.6",
- "windows_i686_msvc 0.52.6",
- "windows_x86_64_gnu 0.52.6",
- "windows_x86_64_gnullvm 0.52.6",
- "windows_x86_64_msvc 0.52.6",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.53.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c66f69fcc9ce11da9966ddb31a40968cad001c5bedeb5c2b82ede4253ab48aef"
-dependencies = [
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- "windows_aarch64_msvc 0.53.0",
- "windows_i686_gnu 0.53.0",
- "windows_i686_gnullvm 0.53.0",
- "windows_i686_msvc 0.53.0",
- "windows_x86_64_gnu 0.53.0",
- "windows_x86_64_gnullvm 0.53.0",
- "windows_x86_64_msvc 0.53.0",
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
 ]

 [[package]]
@@ -4941,96 +4910,48 @@ version = "0.52.6"
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 checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"

-[[package]]
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-
 [[package]]
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-[[package]]
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-
 [[package]]
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-[[package]]
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-
 [[package]]
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-version = "0.53.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
-
 [[package]]
 name = "winnow"
 version = "0.7.10"
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,7 +44,6 @@ ty_ide = { path = "crates/ty_ide" }
 ty_project = { path = "crates/ty_project", default-features = false }
 ty_python_semantic = { path = "crates/ty_python_semantic" }
 ty_server = { path = "crates/ty_server" }
-ty_static = { path = "crates/ty_static" }
 ty_test = { path = "crates/ty_test" }
 ty_vendored = { path = "crates/ty_vendored" }

@@ -84,7 +83,7 @@ get-size2 = { version = "0.5.0", features = [
    "derive",
    "smallvec",
    "hashbrown",
-    "compact-str",
+    "compact-str"
 ] }
 glob = { version = "0.3.1" }
 globset = { version = "0.4.14" }
@@ -99,7 +98,7 @@ ignore = { version = "0.4.22" }
 imara-diff = { version = "0.1.5" }
 imperative = { version = "1.0.4" }
 indexmap = { version = "2.6.0" }
-indicatif = { version = "0.18.0" }
+indicatif = { version = "0.17.8" }
 indoc = { version = "2.0.4" }
 insta = { version = "1.35.1" }
 insta-cmd = { version = "0.6.0" }
@@ -168,13 +167,13 @@ tikv-jemallocator = { version = "0.6.0" }
 toml = { version = "0.8.11" }
 tracing = { version = "0.1.40" }
 tracing-flame = { version = "0.2.0" }
-tracing-indicatif = { version = "0.3.11" }
+tracing-indicatif = { version = "0.3.6" }
 tracing-log = { version = "0.2.0" }
 tracing-subscriber = { version = "0.3.18", default-features = false, features = [
    "env-filter",
    "fmt",
    "ansi",
-    "smallvec",
+    "smallvec"
 ] }
 tryfn = { version = "0.2.1" }
 typed-arena = { version = "2.0.2" }
@@ -184,7 +183,11 @@ unicode-width = { version = "0.2.0" }
 unicode_names2 = { version = "1.2.2" }
 unicode-normalization = { version = "0.1.23" }
 url = { version = "2.5.0" }
-uuid = { version = "1.6.1", features = ["v4", "fast-rng", "macro-diagnostics"] }
+uuid = { version = "1.6.1", features = [
+    "v4",
+    "fast-rng",
+    "macro-diagnostics",
+] }
 walkdir = { version = "2.3.2" }
 wasm-bindgen = { version = "0.2.92" }
 wasm-bindgen-test = { version = "0.3.42" }
@@ -219,8 +222,8 @@ must_use_candidate = "allow"
 similar_names = "allow"
 single_match_else = "allow"
 too_many_lines = "allow"
-needless_continue = "allow" # An explicit continue can be more readable, especially if the alternative is an empty block.
-unnecessary_debug_formatting = "allow" # too many instances, the display also doesn't quote the path which is often desired in logs where we use them the most often.
+needless_continue = "allow"       # An explicit continue can be more readable, especially if the alternative is an empty block.
+unnecessary_debug_formatting = "allow"  # too many instances, the display also doesn't quote the path which is often desired in logs where we use them the most often.
 # Without the hashes we run into a `rustfmt` bug in some snapshot tests, see #13250
 needless_raw_string_hashes = "allow"
 # Disallowed restriction lints
--- a/README.md
+++ b/README.md
@@ -148,8 +148,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"

 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.12.3/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.12.3/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.12.1/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.12.1/install.ps1 | iex"
 ```

 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -182,7 +182,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
  # Ruff version.
-  rev: v0.12.3
+  rev: v0.12.1
  hooks:
    # Run the linter.
    - id: ruff-check
@@ -430,7 +430,6 @@ Ruff is used by a number of major open-source projects and companies, including:
 - [Babel](https://github.com/python-babel/babel)
 - Benchling ([Refac](https://github.com/benchling/refac))
 - [Bokeh](https://github.com/bokeh/bokeh)
- Capital One ([datacompy](https://github.com/capitalone/datacompy))
 - CrowdCent ([NumerBlox](https://github.com/crowdcent/numerblox)) <!-- typos: ignore -->
 - [Cryptography (PyCA)](https://github.com/pyca/cryptography)
 - CERN ([Indico](https://getindico.io/))
@@ -507,7 +506,6 @@ Ruff is used by a number of major open-source projects and companies, including:
 - [Streamlit](https://github.com/streamlit/streamlit)
 - [The Algorithms](https://github.com/TheAlgorithms/Python)
 - [Vega-Altair](https://github.com/altair-viz/altair)
- [Weblate](https://weblate.org/)
 - WordPress ([Openverse](https://github.com/WordPress/openverse))
 - [ZenML](https://github.com/zenml-io/zenml)
 - [Zulip](https://github.com/zulip/zulip)
--- a/crates/ruff/Cargo.toml
+++ b/crates/ruff/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ruff"
-version = "0.12.3"
+version = "0.12.1"
 publish = true
 authors = { workspace = true }
 edition = { workspace = true }
--- a/crates/ruff/src/cache.rs
+++ b/crates/ruff/src/cache.rs
@@ -18,15 +18,14 @@ use rustc_hash::FxHashMap;
 use tempfile::NamedTempFile;

 use ruff_cache::{CacheKey, CacheKeyHasher};
-use ruff_db::diagnostic::Diagnostic;
 use ruff_diagnostics::Fix;
-use ruff_linter::message::create_lint_diagnostic;
+use ruff_linter::message::OldDiagnostic;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::{VERSION, warn_user};
 use ruff_macros::CacheKey;
 use ruff_notebook::NotebookIndex;
 use ruff_source_file::SourceFileBuilder;
-use ruff_text_size::{TextRange, TextSize};
+use ruff_text_size::{Ranged, TextRange, TextSize};
 use ruff_workspace::Settings;
 use ruff_workspace::resolver::Resolver;

@@ -349,7 +348,7 @@ impl FileCache {
                lint.messages
                    .iter()
                    .map(|msg| {
-                        create_lint_diagnostic(
+                        OldDiagnostic::lint(
                            &msg.body,
                            msg.suggestion.as_ref(),
                            msg.range,
@@ -429,11 +428,11 @@ pub(crate) struct LintCacheData {

 impl LintCacheData {
    pub(crate) fn from_diagnostics(
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        notebook_index: Option<NotebookIndex>,
    ) -> Self {
        let source = if let Some(msg) = diagnostics.first() {
-            msg.expect_ruff_source_file().source_text().to_owned()
+            msg.source_file().source_text().to_owned()
        } else {
            String::new() // No messages, no need to keep the source!
        };
@@ -447,16 +446,16 @@ impl LintCacheData {
            .map(|(rule, msg)| {
                // Make sure that all message use the same source file.
                assert_eq!(
-                    msg.expect_ruff_source_file(),
-                    diagnostics.first().unwrap().expect_ruff_source_file(),
+                    msg.source_file(),
+                    diagnostics.first().unwrap().source_file(),
                    "message uses a different source file"
                );
                CacheMessage {
                    rule,
                    body: msg.body().to_string(),
                    suggestion: msg.suggestion().map(ToString::to_string),
-                    range: msg.expect_range(),
-                    parent: msg.parent(),
+                    range: msg.range(),
+                    parent: msg.parent,
                    fix: msg.fix().cloned(),
                    noqa_offset: msg.noqa_offset(),
                }
@@ -609,12 +608,12 @@ mod tests {
    use anyhow::Result;
    use filetime::{FileTime, set_file_mtime};
    use itertools::Itertools;
+    use ruff_linter::settings::LinterSettings;
    use test_case::test_case;

    use ruff_cache::CACHE_DIR_NAME;
-    use ruff_db::diagnostic::Diagnostic;
+    use ruff_linter::message::OldDiagnostic;
    use ruff_linter::package::PackageRoot;
-    use ruff_linter::settings::LinterSettings;
    use ruff_linter::settings::flags;
    use ruff_linter::settings::types::UnsafeFixes;
    use ruff_python_ast::{PySourceType, PythonVersion};
@@ -681,7 +680,7 @@ mod tests {
                    UnsafeFixes::Enabled,
                )
                .unwrap();
-                if diagnostics.inner.iter().any(Diagnostic::is_invalid_syntax) {
+                if diagnostics.inner.iter().any(OldDiagnostic::is_syntax_error) {
                    parse_errors.push(path.clone());
                }
                paths.push(path);
--- a/crates/ruff/src/commands/check.rs
+++ b/crates/ruff/src/commands/check.rs
@@ -11,13 +11,13 @@ use log::{debug, error, warn};
 use rayon::prelude::*;
 use rustc_hash::FxHashMap;

-use ruff_db::diagnostic::Diagnostic;
 use ruff_db::panic::catch_unwind;
+use ruff_linter::OldDiagnostic;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::registry::Rule;
 use ruff_linter::settings::types::UnsafeFixes;
 use ruff_linter::settings::{LinterSettings, flags};
-use ruff_linter::{IOError, Violation, fs, warn_user_once};
+use ruff_linter::{IOError, fs, warn_user_once};
 use ruff_source_file::SourceFileBuilder;
 use ruff_text_size::TextRange;
 use ruff_workspace::resolver::{
@@ -129,7 +129,11 @@ pub(crate) fn check(
                        SourceFileBuilder::new(path.to_string_lossy().as_ref(), "").finish();

                    Diagnostics::new(
-                        vec![IOError { message }.into_diagnostic(TextRange::default(), &dummy)],
+                        vec![OldDiagnostic::new(
+                            IOError { message },
+                            TextRange::default(),
+                            &dummy,
+                        )],
                        FxHashMap::default(),
                    )
                } else {
@@ -162,9 +166,7 @@ pub(crate) fn check(
            |a, b| (a.0 + b.0, a.1 + b.1),
        );

-    all_diagnostics
-        .inner
-        .sort_by(Diagnostic::ruff_start_ordering);
+    all_diagnostics.inner.sort();

    // Store the caches.
    caches.persist()?;
--- a/crates/ruff/src/commands/check_stdin.rs
+++ b/crates/ruff/src/commands/check_stdin.rs
@@ -1,7 +1,6 @@
 use std::path::Path;

 use anyhow::Result;
-use ruff_db::diagnostic::Diagnostic;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::packaging;
 use ruff_linter::settings::flags;
@@ -53,8 +52,6 @@ pub(crate) fn check_stdin(
        noqa,
        fix_mode,
    )?;
-    diagnostics
-        .inner
-        .sort_unstable_by(Diagnostic::ruff_start_ordering);
+    diagnostics.inner.sort_unstable();
    Ok(diagnostics)
 }
--- a/crates/ruff/src/diagnostics.rs
+++ b/crates/ruff/src/diagnostics.rs
@@ -10,35 +10,35 @@ use std::path::Path;
 use anyhow::{Context, Result};
 use colored::Colorize;
 use log::{debug, warn};
-use ruff_db::diagnostic::Diagnostic;
+use rustc_hash::FxHashMap;
+
+use ruff_linter::OldDiagnostic;
 use ruff_linter::codes::Rule;
 use ruff_linter::linter::{FixTable, FixerResult, LinterResult, ParseSource, lint_fix, lint_only};
-use ruff_linter::message::create_syntax_error_diagnostic;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::pyproject_toml::lint_pyproject_toml;
 use ruff_linter::settings::types::UnsafeFixes;
 use ruff_linter::settings::{LinterSettings, flags};
 use ruff_linter::source_kind::{SourceError, SourceKind};
-use ruff_linter::{IOError, Violation, fs};
+use ruff_linter::{IOError, fs};
 use ruff_notebook::{Notebook, NotebookError, NotebookIndex};
 use ruff_python_ast::{PySourceType, SourceType, TomlSourceType};
 use ruff_source_file::SourceFileBuilder;
 use ruff_text_size::TextRange;
 use ruff_workspace::Settings;
-use rustc_hash::FxHashMap;

 use crate::cache::{Cache, FileCacheKey, LintCacheData};

 #[derive(Debug, Default, PartialEq)]
 pub(crate) struct Diagnostics {
-    pub(crate) inner: Vec<Diagnostic>,
+    pub(crate) inner: Vec<OldDiagnostic>,
    pub(crate) fixed: FixMap,
    pub(crate) notebook_indexes: FxHashMap<String, NotebookIndex>,
 }

 impl Diagnostics {
    pub(crate) fn new(
-        diagnostics: Vec<Diagnostic>,
+        diagnostics: Vec<OldDiagnostic>,
        notebook_indexes: FxHashMap<String, NotebookIndex>,
    ) -> Self {
        Self {
@@ -62,12 +62,13 @@ impl Diagnostics {
                    let name = path.map_or_else(|| "-".into(), Path::to_string_lossy);
                    let source_file = SourceFileBuilder::new(name, "").finish();
                    Self::new(
-                        vec![
+                        vec![OldDiagnostic::new(
                            IOError {
                                message: err.to_string(),
-                            }
-                            .into_diagnostic(TextRange::default(), &source_file),
-                        ],
+                            },
+                            TextRange::default(),
+                            &source_file,
+                        )],
                        FxHashMap::default(),
                    )
                } else {
@@ -97,10 +98,10 @@ impl Diagnostics {
                let name = path.map_or_else(|| "-".into(), Path::to_string_lossy);
                let dummy = SourceFileBuilder::new(name, "").finish();
                Self::new(
-                    vec![create_syntax_error_diagnostic(
-                        dummy,
+                    vec![OldDiagnostic::syntax_error(
                        err,
                        TextRange::default(),
+                        dummy,
                    )],
                    FxHashMap::default(),
                )
--- a/crates/ruff/src/lib.rs
+++ b/crates/ruff/src/lib.rs
@@ -439,7 +439,7 @@ pub fn check(args: CheckCommand, global_options: GlobalConfigArgs) -> Result<Exi
        if cli.statistics {
            printer.write_statistics(&diagnostics, &mut summary_writer)?;
        } else {
-            printer.write_once(&diagnostics, &mut summary_writer, preview)?;
+            printer.write_once(&diagnostics, &mut summary_writer)?;
        }

        if !cli.exit_zero {
--- a/crates/ruff/src/printer.rs
+++ b/crates/ruff/src/printer.rs
@@ -9,14 +9,12 @@ use itertools::{Itertools, iterate};
 use ruff_linter::linter::FixTable;
 use serde::Serialize;

-use ruff_db::diagnostic::{
-    Diagnostic, DiagnosticFormat, DisplayDiagnosticConfig, DisplayDiagnostics, SecondaryCode,
-};
 use ruff_linter::fs::relativize_path;
 use ruff_linter::logging::LogLevel;
 use ruff_linter::message::{
-    Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter, JunitEmitter,
-    PylintEmitter, RdjsonEmitter, SarifEmitter, TextEmitter,
+    AzureEmitter, Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter,
+    JsonEmitter, JsonLinesEmitter, JunitEmitter, OldDiagnostic, PylintEmitter, RdjsonEmitter,
+    SarifEmitter, SecondaryCode, TextEmitter,
 };
 use ruff_linter::notify_user;
 use ruff_linter::settings::flags::{self};
@@ -203,7 +201,6 @@ impl Printer {
        &self,
        diagnostics: &Diagnostics,
        writer: &mut dyn Write,
-        preview: bool,
    ) -> Result<()> {
        if matches!(self.log_level, LogLevel::Silent) {
            return Ok(());
@@ -231,21 +228,13 @@ impl Printer {

        match self.format {
            OutputFormat::Json => {
-                let config = DisplayDiagnosticConfig::default()
-                    .format(DiagnosticFormat::Json)
-                    .preview(preview);
-                let value = DisplayDiagnostics::new(&context, &config, &diagnostics.inner);
-                write!(writer, "{value}")?;
+                JsonEmitter.emit(writer, &diagnostics.inner, &context)?;
            }
            OutputFormat::Rdjson => {
                RdjsonEmitter.emit(writer, &diagnostics.inner, &context)?;
            }
            OutputFormat::JsonLines => {
-                let config = DisplayDiagnosticConfig::default()
-                    .format(DiagnosticFormat::JsonLines)
-                    .preview(preview);
-                let value = DisplayDiagnostics::new(&context, &config, &diagnostics.inner);
-                write!(writer, "{value}")?;
+                JsonLinesEmitter.emit(writer, &diagnostics.inner, &context)?;
            }
            OutputFormat::Junit => {
                JunitEmitter.emit(writer, &diagnostics.inner, &context)?;
@@ -293,11 +282,7 @@ impl Printer {
                PylintEmitter.emit(writer, &diagnostics.inner, &context)?;
            }
            OutputFormat::Azure => {
-                let config = DisplayDiagnosticConfig::default()
-                    .format(DiagnosticFormat::Azure)
-                    .preview(preview);
-                let value = DisplayDiagnostics::new(&context, &config, &diagnostics.inner);
-                write!(writer, "{value}")?;
+                AzureEmitter.emit(writer, &diagnostics.inner, &context)?;
            }
            OutputFormat::Sarif => {
                SarifEmitter.emit(writer, &diagnostics.inner, &context)?;
@@ -321,7 +306,8 @@ impl Printer {
            .sorted_by_key(|(code, message)| (*code, message.fixable()))
            .fold(
                vec![],
-                |mut acc: Vec<((Option<&SecondaryCode>, &Diagnostic), usize)>, (code, message)| {
+                |mut acc: Vec<((Option<&SecondaryCode>, &OldDiagnostic), usize)>,
+                 (code, message)| {
                    if let Some(((prev_code, _prev_message), count)) = acc.last_mut() {
                        if *prev_code == code {
                            *count += 1;
--- a/crates/ruff/tests/integration_test.rs
+++ b/crates/ruff/tests/integration_test.rs
@@ -1067,7 +1067,7 @@ fn show_statistics_syntax_errors() {
    success: false
    exit_code: 1
    ----- stdout -----
-    1		invalid-syntax
+    1		syntax-error
    Found 1 error.

    ----- stderr -----
@@ -1080,7 +1080,7 @@ fn show_statistics_syntax_errors() {
    success: false
    exit_code: 1
    ----- stdout -----
-    1		invalid-syntax
+    1		syntax-error
    Found 1 error.

    ----- stderr -----
@@ -1093,7 +1093,7 @@ fn show_statistics_syntax_errors() {
    success: false
    exit_code: 1
    ----- stdout -----
-    1		invalid-syntax
+    1		syntax-error
    Found 1 error.

    ----- stderr -----
--- a/crates/ruff/tests/lint.rs
+++ b/crates/ruff/tests/lint.rs
@@ -5692,57 +5692,3 @@ class Foo:
    "
    );
 }
-
-#[test_case::test_case("concise")]
-#[test_case::test_case("full")]
-#[test_case::test_case("json")]
-#[test_case::test_case("json-lines")]
-#[test_case::test_case("junit")]
-#[test_case::test_case("grouped")]
-#[test_case::test_case("github")]
-#[test_case::test_case("gitlab")]
-#[test_case::test_case("pylint")]
-#[test_case::test_case("rdjson")]
-#[test_case::test_case("azure")]
-#[test_case::test_case("sarif")]
-fn output_format(output_format: &str) -> Result<()> {
-    const CONTENT: &str = "\
-import os  # F401
-x = y      # F821
-match 42:  # invalid-syntax
-    case _: ...
-";
-
-    let tempdir = TempDir::new()?;
-    let input = tempdir.path().join("input.py");
-    fs::write(&input, CONTENT)?;
-
-    let snapshot = format!("output_format_{output_format}");
-
-    insta::with_settings!({
-        filters => vec![
-            (tempdir_filter(&tempdir).as_str(), "[TMP]/"),
-            (r#""[^"]+\\?/?input.py"#, r#""[TMP]/input.py"#),
-            (ruff_linter::VERSION, "[VERSION]"),
-        ]
-    }, {
-        assert_cmd_snapshot!(
-            snapshot,
-            Command::new(get_cargo_bin(BIN_NAME))
-                .args([
-                    "check",
-                    "--no-cache",
-                    "--output-format",
-                    output_format,
-                    "--select",
-                    "F401,F821",
-                    "--target-version",
-                    "py39",
-                    "input.py",
-                ])
-                .current_dir(&tempdir),
-        );
-    });
-
-    Ok(())
-}
--- a/crates/ruff/tests/snapshots/lint__output_format_azure.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_azure.snap
@@ -1,23 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - azure
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-##vso[task.logissue type=error;sourcepath=[TMP]/input.py;linenumber=1;columnnumber=8;code=F401;]`os` imported but unused
-##vso[task.logissue type=error;sourcepath=[TMP]/input.py;linenumber=2;columnnumber=5;code=F821;]Undefined name `y`
-##vso[task.logissue type=error;sourcepath=[TMP]/input.py;linenumber=3;columnnumber=1;]SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_concise.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_concise.snap
@@ -1,25 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - concise
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-input.py:1:8: F401 [*] `os` imported but unused
-input.py:2:5: F821 Undefined name `y`
-input.py:3:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
-Found 3 errors.
-[*] 1 fixable with the `--fix` option.
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_full.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_full.snap
@@ -1,49 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - full
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-input.py:1:8: F401 [*] `os` imported but unused
-  |
-1 | import os  # F401
-  |        ^^ F401
-2 | x = y      # F821
-3 | match 42:  # invalid-syntax
-  |
-  = help: Remove unused import: `os`
-
-input.py:2:5: F821 Undefined name `y`
-  |
-1 | import os  # F401
-2 | x = y      # F821
-  |     ^ F821
-3 | match 42:  # invalid-syntax
-4 |     case _: ...
-  |
-
-input.py:3:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
-  |
-1 | import os  # F401
-2 | x = y      # F821
-3 | match 42:  # invalid-syntax
-  | ^^^^^
-4 |     case _: ...
-  |
-
-Found 3 errors.
-[*] 1 fixable with the `--fix` option.
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_github.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_github.snap
@@ -1,23 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - github
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-::error title=Ruff (F401),file=[TMP]/input.py,line=1,col=8,endLine=1,endColumn=10::input.py:1:8: F401 `os` imported but unused
-::error title=Ruff (F821),file=[TMP]/input.py,line=2,col=5,endLine=2,endColumn=6::input.py:2:5: F821 Undefined name `y`
-::error title=Ruff,file=[TMP]/input.py,line=3,col=1,endLine=3,endColumn=6::input.py:3:1: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_gitlab.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_gitlab.snap
@@ -1,60 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - gitlab
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-[
-  {
-    "check_name": "F401",
-    "description": "`os` imported but unused",
-    "fingerprint": "4dbad37161e65c72",
-    "location": {
-      "lines": {
-        "begin": 1,
-        "end": 1
-      },
-      "path": "input.py"
-    },
-    "severity": "major"
-  },
-  {
-    "check_name": "F821",
-    "description": "Undefined name `y`",
-    "fingerprint": "7af59862a085230",
-    "location": {
-      "lines": {
-        "begin": 2,
-        "end": 2
-      },
-      "path": "input.py"
-    },
-    "severity": "major"
-  },
-  {
-    "check_name": "syntax-error",
-    "description": "Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)",
-    "fingerprint": "e558cec859bb66e8",
-    "location": {
-      "lines": {
-        "begin": 3,
-        "end": 3
-      },
-      "path": "input.py"
-    },
-    "severity": "major"
-  }
-]
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_grouped.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_grouped.snap
@@ -1,27 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - grouped
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-input.py:
-  1:8 F401 [*] `os` imported but unused
-  2:5 F821 Undefined name `y`
-  3:1 SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
-
-Found 3 errors.
-[*] 1 fixable with the `--fix` option.
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_json-lines.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_json-lines.snap
@@ -1,23 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - json-lines
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-{"cell":null,"code":"F401","end_location":{"column":10,"row":1},"filename":"[TMP]/input.py","fix":{"applicability":"safe","edits":[{"content":"","end_location":{"column":1,"row":2},"location":{"column":1,"row":1}}],"message":"Remove unused import: `os`"},"location":{"column":8,"row":1},"message":"`os` imported but unused","noqa_row":1,"url":"https://docs.astral.sh/ruff/rules/unused-import"}
-{"cell":null,"code":"F821","end_location":{"column":6,"row":2},"filename":"[TMP]/input.py","fix":null,"location":{"column":5,"row":2},"message":"Undefined name `y`","noqa_row":2,"url":"https://docs.astral.sh/ruff/rules/undefined-name"}
-{"cell":null,"code":null,"end_location":{"column":6,"row":3},"filename":"[TMP]/input.py","fix":null,"location":{"column":1,"row":3},"message":"SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)","noqa_row":null,"url":null}
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_json.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_json.snap
@@ -1,88 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - json
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-[
-  {
-    "cell": null,
-    "code": "F401",
-    "end_location": {
-      "column": 10,
-      "row": 1
-    },
-    "filename": "[TMP]/input.py",
-    "fix": {
-      "applicability": "safe",
-      "edits": [
-        {
-          "content": "",
-          "end_location": {
-            "column": 1,
-            "row": 2
-          },
-          "location": {
-            "column": 1,
-            "row": 1
-          }
-        }
-      ],
-      "message": "Remove unused import: `os`"
-    },
-    "location": {
-      "column": 8,
-      "row": 1
-    },
-    "message": "`os` imported but unused",
-    "noqa_row": 1,
-    "url": "https://docs.astral.sh/ruff/rules/unused-import"
-  },
-  {
-    "cell": null,
-    "code": "F821",
-    "end_location": {
-      "column": 6,
-      "row": 2
-    },
-    "filename": "[TMP]/input.py",
-    "fix": null,
-    "location": {
-      "column": 5,
-      "row": 2
-    },
-    "message": "Undefined name `y`",
-    "noqa_row": 2,
-    "url": "https://docs.astral.sh/ruff/rules/undefined-name"
-  },
-  {
-    "cell": null,
-    "code": null,
-    "end_location": {
-      "column": 6,
-      "row": 3
-    },
-    "filename": "[TMP]/input.py",
-    "fix": null,
-    "location": {
-      "column": 1,
-      "row": 3
-    },
-    "message": "SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)",
-    "noqa_row": null,
-    "url": null
-  }
-]
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_junit.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_junit.snap
@@ -1,34 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - junit
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-<?xml version="1.0" encoding="UTF-8"?>
-<testsuites name="ruff" tests="3" failures="3" errors="0">
-    <testsuite name="[TMP]/input.py" tests="3" disabled="0" errors="0" failures="3" package="org.ruff">
-        <testcase name="org.ruff.F401" classname="[TMP]/input" line="1" column="8">
-            <failure message="`os` imported but unused">line 1, col 8, `os` imported but unused</failure>
-        </testcase>
-        <testcase name="org.ruff.F821" classname="[TMP]/input" line="2" column="5">
-            <failure message="Undefined name `y`">line 2, col 5, Undefined name `y`</failure>
-        </testcase>
-        <testcase name="org.ruff" classname="[TMP]/input" line="3" column="1">
-            <failure message="SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)">line 3, col 1, SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)</failure>
-        </testcase>
-    </testsuite>
-</testsuites>
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_pylint.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_pylint.snap
@@ -1,23 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - pylint
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-input.py:1: [F401] `os` imported but unused
-input.py:2: [F821] Undefined name `y`
-input.py:3: SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
-
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_rdjson.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_rdjson.snap
@@ -1,103 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - rdjson
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-{
-  "diagnostics": [
-    {
-      "code": {
-        "url": "https://docs.astral.sh/ruff/rules/unused-import",
-        "value": "F401"
-      },
-      "location": {
-        "path": "[TMP]/input.py",
-        "range": {
-          "end": {
-            "column": 10,
-            "line": 1
-          },
-          "start": {
-            "column": 8,
-            "line": 1
-          }
-        }
-      },
-      "message": "`os` imported but unused",
-      "suggestions": [
-        {
-          "range": {
-            "end": {
-              "column": 1,
-              "line": 2
-            },
-            "start": {
-              "column": 1,
-              "line": 1
-            }
-          },
-          "text": ""
-        }
-      ]
-    },
-    {
-      "code": {
-        "url": "https://docs.astral.sh/ruff/rules/undefined-name",
-        "value": "F821"
-      },
-      "location": {
-        "path": "[TMP]/input.py",
-        "range": {
-          "end": {
-            "column": 6,
-            "line": 2
-          },
-          "start": {
-            "column": 5,
-            "line": 2
-          }
-        }
-      },
-      "message": "Undefined name `y`"
-    },
-    {
-      "code": {
-        "url": null,
-        "value": null
-      },
-      "location": {
-        "path": "[TMP]/input.py",
-        "range": {
-          "end": {
-            "column": 6,
-            "line": 3
-          },
-          "start": {
-            "column": 1,
-            "line": 3
-          }
-        }
-      },
-      "message": "SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
-    }
-  ],
-  "severity": "warning",
-  "source": {
-    "name": "ruff",
-    "url": "https://docs.astral.sh/ruff"
-  }
-}
----- stderr -----
--- a/crates/ruff/tests/snapshots/lint__output_format_sarif.snap
+++ b/crates/ruff/tests/snapshots/lint__output_format_sarif.snap
@@ -1,142 +0,0 @@
---
-source: crates/ruff/tests/lint.rs
-info:
-  program: ruff
-  args:
-    - check
-    - "--no-cache"
-    - "--output-format"
-    - sarif
-    - "--select"
-    - "F401,F821"
-    - "--target-version"
-    - py39
-    - input.py
---
-success: false
-exit_code: 1
----- stdout -----
-{
-  "$schema": "https://json.schemastore.org/sarif-2.1.0.json",
-  "runs": [
-    {
-      "results": [
-        {
-          "level": "error",
-          "locations": [
-            {
-              "physicalLocation": {
-                "artifactLocation": {
-                  "uri": "[TMP]/input.py"
-                },
-                "region": {
-                  "endColumn": 10,
-                  "endLine": 1,
-                  "startColumn": 8,
-                  "startLine": 1
-                }
-              }
-            }
-          ],
-          "message": {
-            "text": "`os` imported but unused"
-          },
-          "ruleId": "F401"
-        },
-        {
-          "level": "error",
-          "locations": [
-            {
-              "physicalLocation": {
-                "artifactLocation": {
-                  "uri": "[TMP]/input.py"
-                },
-                "region": {
-                  "endColumn": 6,
-                  "endLine": 2,
-                  "startColumn": 5,
-                  "startLine": 2
-                }
-              }
-            }
-          ],
-          "message": {
-            "text": "Undefined name `y`"
-          },
-          "ruleId": "F821"
-        },
-        {
-          "level": "error",
-          "locations": [
-            {
-              "physicalLocation": {
-                "artifactLocation": {
-                  "uri": "[TMP]/input.py"
-                },
-                "region": {
-                  "endColumn": 6,
-                  "endLine": 3,
-                  "startColumn": 1,
-                  "startLine": 3
-                }
-              }
-            }
-          ],
-          "message": {
-            "text": "SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
-          },
-          "ruleId": null
-        }
-      ],
-      "tool": {
-        "driver": {
-          "informationUri": "https://github.com/astral-sh/ruff",
-          "name": "ruff",
-          "rules": [
-            {
-              "fullDescription": {
-                "text": "## What it does\nChecks for unused imports.\n\n## Why is this bad?\nUnused imports add a performance overhead at runtime, and risk creating\nimport cycles. They also increase the cognitive load of reading the code.\n\nIf an import statement is used to check for the availability or existence\nof a module, consider using `importlib.util.find_spec` instead.\n\nIf an import statement is used to re-export a symbol as part of a module's\npublic interface, consider using a \"redundant\" import alias, which\ninstructs Ruff (and other tools) to respect the re-export, and avoid\nmarking it as unused, as in:\n\n```python\nfrom module import member as member\n```\n\nAlternatively, you can use `__all__` to declare a symbol as part of the module's\ninterface, as in:\n\n```python\n# __init__.py\nimport some_module\n\n__all__ = [\"some_module\"]\n```\n\n## Fix safety\n\nFixes to remove unused imports are safe, except in `__init__.py` files.\n\nApplying fixes to `__init__.py` files is currently in preview. The fix offered depends on the\ntype of the unused import. Ruff will suggest a safe fix to export first-party imports with\neither a redundant alias or, if already present in the file, an `__all__` entry. If multiple\n`__all__` declarations are present, Ruff will not offer a fix. Ruff will suggest an unsafe fix\nto remove third-party and standard library imports -- the fix is unsafe because the module's\ninterface changes.\n\n## Example\n\n```python\nimport numpy as np  # unused import\n\n\ndef area(radius):\n    return 3.14 * radius**2\n```\n\nUse instead:\n\n```python\ndef area(radius):\n    return 3.14 * radius**2\n```\n\nTo check the availability of a module, use `importlib.util.find_spec`:\n\n```python\nfrom importlib.util import find_spec\n\nif find_spec(\"numpy\") is not None:\n    print(\"numpy is installed\")\nelse:\n    print(\"numpy is not installed\")\n```\n\n## Preview\nWhen [preview](https://docs.astral.sh/ruff/preview/) is enabled,\nthe criterion for determining whether an import is first-party\nis stricter, which could affect the suggested fix. See [this FAQ section](https://docs.astral.sh/ruff/faq/#how-does-ruff-determine-which-of-my-imports-are-first-party-third-party-etc) for more details.\n\n## Options\n- `lint.ignore-init-module-imports`\n- `lint.pyflakes.allowed-unused-imports`\n\n## References\n- [Python documentation: `import`](https://docs.python.org/3/reference/simple_stmts.html#the-import-statement)\n- [Python documentation: `importlib.util.find_spec`](https://docs.python.org/3/library/importlib.html#importlib.util.find_spec)\n- [Typing documentation: interface conventions](https://typing.python.org/en/latest/source/libraries.html#library-interface-public-and-private-symbols)\n"
-              },
-              "help": {
-                "text": "`{name}` imported but unused; consider using `importlib.util.find_spec` to test for availability"
-              },
-              "helpUri": "https://docs.astral.sh/ruff/rules/unused-import",
-              "id": "F401",
-              "properties": {
-                "id": "F401",
-                "kind": "Pyflakes",
-                "name": "unused-import",
-                "problem.severity": "error"
-              },
-              "shortDescription": {
-                "text": "`{name}` imported but unused; consider using `importlib.util.find_spec` to test for availability"
-              }
-            },
-            {
-              "fullDescription": {
-                "text": "## What it does\nChecks for uses of undefined names.\n\n## Why is this bad?\nAn undefined name is likely to raise `NameError` at runtime.\n\n## Example\n```python\ndef double():\n    return n * 2  # raises `NameError` if `n` is undefined when `double` is called\n```\n\nUse instead:\n```python\ndef double(n):\n    return n * 2\n```\n\n## Options\n- [`target-version`]: Can be used to configure which symbols Ruff will understand\n  as being available in the `builtins` namespace.\n\n## References\n- [Python documentation: Naming and binding](https://docs.python.org/3/reference/executionmodel.html#naming-and-binding)\n"
-              },
-              "help": {
-                "text": "Undefined name `{name}`. {tip}"
-              },
-              "helpUri": "https://docs.astral.sh/ruff/rules/undefined-name",
-              "id": "F821",
-              "properties": {
-                "id": "F821",
-                "kind": "Pyflakes",
-                "name": "undefined-name",
-                "problem.severity": "error"
-              },
-              "shortDescription": {
-                "text": "Undefined name `{name}`. {tip}"
-              }
-            }
-          ],
-          "version": "[VERSION]"
-        }
-      }
-    }
-  ],
-  "version": "2.1.0"
-}
----- stderr -----
--- a/crates/ruff_benchmark/benches/ty.rs
+++ b/crates/ruff_benchmark/benches/ty.rs
@@ -498,8 +498,11 @@ fn bench_project(benchmark: &ProjectBenchmark, criterion: &mut Criterion) {
        let diagnostics = result.len();

        assert!(
-            diagnostics <= max_diagnostics,
-            "Expected <={max_diagnostics} diagnostics but got {diagnostics}"
+            diagnostics > 1 && diagnostics <= max_diagnostics,
+            "Expected between {} and {} diagnostics but got {}",
+            1,
+            max_diagnostics,
+            diagnostics
        );
    }

@@ -567,23 +570,6 @@ fn anyio(criterion: &mut Criterion) {
    bench_project(&benchmark, criterion);
 }

-fn datetype(criterion: &mut Criterion) {
-    let benchmark = ProjectBenchmark::new(
-        RealWorldProject {
-            name: "DateType",
-            repository: "https://github.com/glyph/DateType",
-            commit: "57c9c93cf2468069f72945fc04bf27b64100dad8",
-            paths: vec![SystemPath::new("src")],
-            dependencies: vec![],
-            max_dep_date: "2025-07-04",
-            python_version: PythonVersion::PY313,
-        },
-        0,
-    );
-
-    bench_project(&benchmark, criterion);
-}
-
 criterion_group!(check_file, benchmark_cold, benchmark_incremental);
 criterion_group!(
    micro,
@@ -592,5 +578,5 @@ criterion_group!(
    benchmark_complex_constrained_attributes_1,
    benchmark_complex_constrained_attributes_2,
 );
-criterion_group!(project, anyio, attrs, hydra, datetype);
+criterion_group!(project, anyio, attrs, hydra);
 criterion_main!(check_file, micro, project);
--- a/crates/ruff_benchmark/benches/ty_walltime.rs
+++ b/crates/ruff_benchmark/benches/ty_walltime.rs
@@ -242,7 +242,7 @@ fn large(bencher: Bencher, benchmark: &Benchmark) {
    run_single_threaded(bencher, benchmark);
 }

-#[bench(args=[&*PYDANTIC], sample_size=3, sample_count=8)]
+#[bench(args=[&*PYDANTIC], sample_size=3, sample_count=3)]
 fn multithreaded(bencher: Bencher, benchmark: &Benchmark) {
    let thread_pool = ThreadPoolBuilder::new().build().unwrap();

--- a/crates/ruff_db/Cargo.toml
+++ b/crates/ruff_db/Cargo.toml
@@ -13,14 +13,12 @@ license = { workspace = true }
 [dependencies]
 ruff_annotate_snippets = { workspace = true }
 ruff_cache = { workspace = true, optional = true }
-ruff_diagnostics = { workspace = true }
 ruff_notebook = { workspace = true }
 ruff_python_ast = { workspace = true, features = ["get-size"] }
 ruff_python_parser = { workspace = true }
 ruff_python_trivia = { workspace = true }
 ruff_source_file = { workspace = true, features = ["get-size"] }
 ruff_text_size = { workspace = true }
-ty_static = { workspace = true }

 anstyle = { workspace = true }
 arc-swap = { workspace = true }
@@ -38,7 +36,6 @@ rustc-hash = { workspace = true }
 salsa = { workspace = true }
 schemars = { workspace = true, optional = true }
 serde = { workspace = true, optional = true }
-serde_json = { workspace = true, optional = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 tracing-subscriber = { workspace = true, optional = true }
@@ -57,6 +54,6 @@ tempfile = { workspace = true }
 [features]
 cache = ["ruff_cache"]
 os = ["ignore", "dep:etcetera"]
-serde = ["camino/serde1", "dep:serde", "dep:serde_json", "ruff_diagnostics/serde"]
+serde = ["dep:serde", "camino/serde1"]
 # Exposes testing utilities.
 testing = ["tracing-subscriber"]
--- a/crates/ruff_db/src/diagnostic/mod.rs
+++ b/crates/ruff_db/src/diagnostic/mod.rs
@@ -1,12 +1,12 @@
 use std::{fmt::Formatter, sync::Arc};

-use ruff_diagnostics::Fix;
-use ruff_source_file::{LineColumn, SourceCode, SourceFile};
+use render::{FileResolver, Input};
+use ruff_source_file::{SourceCode, SourceFile};

 use ruff_annotate_snippets::Level as AnnotateLevel;
-use ruff_text_size::{Ranged, TextRange, TextSize};
+use ruff_text_size::{Ranged, TextRange};

-pub use self::render::{DisplayDiagnostic, DisplayDiagnostics, FileResolver, Input};
+pub use self::render::DisplayDiagnostic;
 use crate::{Db, files::File};

 mod render;
@@ -62,37 +62,10 @@ impl Diagnostic {
            message: message.into_diagnostic_message(),
            annotations: vec![],
            subs: vec![],
-            fix: None,
-            parent: None,
-            noqa_offset: None,
-            secondary_code: None,
        });
        Diagnostic { inner }
    }

-    /// Creates a `Diagnostic` for a syntax error.
-    ///
-    /// Unlike the more general [`Diagnostic::new`], this requires a [`Span`] and a [`TextRange`]
-    /// attached to it.
-    ///
-    /// This should _probably_ be a method on the syntax errors, but
-    /// at time of writing, `ruff_db` depends on `ruff_python_parser` instead of
-    /// the other way around. And since we want to do this conversion in a couple
-    /// places, it makes sense to centralize it _somewhere_. So it's here for now.
-    ///
-    /// Note that `message` is stored in the primary annotation, _not_ in the primary diagnostic
-    /// message.
-    pub fn invalid_syntax(
-        span: impl Into<Span>,
-        message: impl IntoDiagnosticMessage,
-        range: impl Ranged,
-    ) -> Diagnostic {
-        let mut diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, "");
-        let span = span.into().with_range(range.range());
-        diag.annotate(Annotation::primary(span).message(message));
-        diag
-    }
-
    /// Add an annotation to this diagnostic.
    ///
    /// Annotations for a diagnostic are optional, but if any are added,
@@ -253,11 +226,6 @@ impl Diagnostic {
        self.primary_annotation().map(|ann| ann.span.clone())
    }

-    /// Returns a reference to the primary span of this diagnostic.
-    pub fn primary_span_ref(&self) -> Option<&Span> {
-        self.primary_annotation().map(|ann| &ann.span)
-    }
-
    /// Returns the tags from the primary annotation of this diagnostic if it exists.
    pub fn primary_tags(&self) -> Option<&[DiagnosticTag]> {
        self.primary_annotation().map(|ann| ann.tags.as_slice())
@@ -300,164 +268,6 @@ impl Diagnostic {
    pub fn sub_diagnostics(&self) -> &[SubDiagnostic] {
        &self.inner.subs
    }
-
-    /// Returns the fix for this diagnostic if it exists.
-    pub fn fix(&self) -> Option<&Fix> {
-        self.inner.fix.as_ref()
-    }
-
-    /// Set the fix for this diagnostic.
-    pub fn set_fix(&mut self, fix: Fix) {
-        Arc::make_mut(&mut self.inner).fix = Some(fix);
-    }
-
-    /// Remove the fix for this diagnostic.
-    pub fn remove_fix(&mut self) {
-        Arc::make_mut(&mut self.inner).fix = None;
-    }
-
-    /// Returns `true` if the diagnostic contains a [`Fix`].
-    pub fn fixable(&self) -> bool {
-        self.fix().is_some()
-    }
-
-    /// Returns the offset of the parent statement for this diagnostic if it exists.
-    ///
-    /// This is primarily used for checking noqa/secondary code suppressions.
-    pub fn parent(&self) -> Option<TextSize> {
-        self.inner.parent
-    }
-
-    /// Set the offset of the diagnostic's parent statement.
-    pub fn set_parent(&mut self, parent: TextSize) {
-        Arc::make_mut(&mut self.inner).parent = Some(parent);
-    }
-
-    /// Returns the remapped offset for a suppression comment if it exists.
-    ///
-    /// Like [`Diagnostic::parent`], this is used for noqa code suppression comments in Ruff.
-    pub fn noqa_offset(&self) -> Option<TextSize> {
-        self.inner.noqa_offset
-    }
-
-    /// Set the remapped offset for a suppression comment.
-    pub fn set_noqa_offset(&mut self, noqa_offset: TextSize) {
-        Arc::make_mut(&mut self.inner).noqa_offset = Some(noqa_offset);
-    }
-
-    /// Returns the secondary code for the diagnostic if it exists.
-    ///
-    /// The "primary" code for the diagnostic is its lint name. Diagnostics in ty don't have
-    /// secondary codes (yet), but in Ruff the noqa code is used.
-    pub fn secondary_code(&self) -> Option<&SecondaryCode> {
-        self.inner.secondary_code.as_ref()
-    }
-
-    /// Set the secondary code for this diagnostic.
-    pub fn set_secondary_code(&mut self, code: SecondaryCode) {
-        Arc::make_mut(&mut self.inner).secondary_code = Some(code);
-    }
-
-    /// Returns the name used to represent the diagnostic.
-    pub fn name(&self) -> &'static str {
-        self.id().as_str()
-    }
-
-    /// Returns `true` if `self` is a syntax error message.
-    pub fn is_invalid_syntax(&self) -> bool {
-        self.id().is_invalid_syntax()
-    }
-
-    /// Returns the message body to display to the user.
-    pub fn body(&self) -> &str {
-        self.primary_message()
-    }
-
-    /// Returns the fix suggestion for the violation.
-    pub fn suggestion(&self) -> Option<&str> {
-        self.primary_annotation()?.get_message()
-    }
-
-    /// Returns the URL for the rule documentation, if it exists.
-    pub fn to_ruff_url(&self) -> Option<String> {
-        if self.is_invalid_syntax() {
-            None
-        } else {
-            Some(format!(
-                "{}/rules/{}",
-                env!("CARGO_PKG_HOMEPAGE"),
-                self.name()
-            ))
-        }
-    }
-
-    /// Returns the filename for the message.
-    ///
-    /// Panics if the diagnostic has no primary span, or if its file is not a `SourceFile`.
-    pub fn expect_ruff_filename(&self) -> String {
-        self.expect_primary_span()
-            .expect_ruff_file()
-            .name()
-            .to_string()
-    }
-
-    /// Computes the start source location for the message.
-    ///
-    /// Panics if the diagnostic has no primary span, if its file is not a `SourceFile`, or if the
-    /// span has no range.
-    pub fn expect_ruff_start_location(&self) -> LineColumn {
-        self.expect_primary_span()
-            .expect_ruff_file()
-            .to_source_code()
-            .line_column(self.expect_range().start())
-    }
-
-    /// Computes the end source location for the message.
-    ///
-    /// Panics if the diagnostic has no primary span, if its file is not a `SourceFile`, or if the
-    /// span has no range.
-    pub fn expect_ruff_end_location(&self) -> LineColumn {
-        self.expect_primary_span()
-            .expect_ruff_file()
-            .to_source_code()
-            .line_column(self.expect_range().end())
-    }
-
-    /// Returns the [`SourceFile`] which the message belongs to.
-    pub fn ruff_source_file(&self) -> Option<&SourceFile> {
-        self.primary_span_ref()?.as_ruff_file()
-    }
-
-    /// Returns the [`SourceFile`] which the message belongs to.
-    ///
-    /// Panics if the diagnostic has no primary span, or if its file is not a `SourceFile`.
-    pub fn expect_ruff_source_file(&self) -> &SourceFile {
-        self.ruff_source_file()
-            .expect("Expected a ruff source file")
-    }
-
-    /// Returns the [`TextRange`] for the diagnostic.
-    pub fn range(&self) -> Option<TextRange> {
-        self.primary_span()?.range()
-    }
-
-    /// Returns the [`TextRange`] for the diagnostic.
-    ///
-    /// Panics if the diagnostic has no primary span or if the span has no range.
-    pub fn expect_range(&self) -> TextRange {
-        self.range().expect("Expected a range for the primary span")
-    }
-
-    /// Returns the ordering of diagnostics based on the start of their ranges, if they have any.
-    ///
-    /// Panics if either diagnostic has no primary span, if the span has no range, or if its file is
-    /// not a `SourceFile`.
-    pub fn ruff_start_ordering(&self, other: &Self) -> std::cmp::Ordering {
-        (self.expect_ruff_source_file(), self.expect_range().start()).cmp(&(
-            other.expect_ruff_source_file(),
-            other.expect_range().start(),
-        ))
-    }
 }

 #[derive(Debug, Clone, Eq, PartialEq, get_size2::GetSize)]
@@ -467,10 +277,6 @@ struct DiagnosticInner {
    message: DiagnosticMessage,
    annotations: Vec<Annotation>,
    subs: Vec<SubDiagnostic>,
-    fix: Option<Fix>,
-    parent: Option<TextSize>,
-    noqa_offset: Option<TextSize>,
-    secondary_code: Option<SecondaryCode>,
 }

 struct RenderingSortKey<'a> {
@@ -1091,15 +897,9 @@ impl Span {
    ///
    /// Panics if the file is a [`UnifiedFile::Ty`] instead of a [`UnifiedFile::Ruff`].
    pub fn expect_ruff_file(&self) -> &SourceFile {
-        self.as_ruff_file()
-            .expect("Expected a ruff `SourceFile`, found a ty `File`")
-    }
-
-    /// Returns the [`SourceFile`] attached to this [`Span`].
-    pub fn as_ruff_file(&self) -> Option<&SourceFile> {
        match &self.file {
-            UnifiedFile::Ty(_) => None,
-            UnifiedFile::Ruff(file) => Some(file),
+            UnifiedFile::Ty(_) => panic!("Expected a ruff `SourceFile`, found a ty `File`"),
+            UnifiedFile::Ruff(file) => file,
        }
    }
 }
@@ -1174,12 +974,6 @@ pub struct DisplayDiagnosticConfig {
    /// here for now as the most "sensible" place for it to live until
    /// we had more concrete use cases. ---AG
    context: usize,
-    /// Whether to use preview formatting for Ruff diagnostics.
-    #[allow(
-        dead_code,
-        reason = "This is currently only used for JSON but will be needed soon for other formats"
-    )]
-    preview: bool,
 }

 impl DisplayDiagnosticConfig {
@@ -1200,14 +994,6 @@ impl DisplayDiagnosticConfig {
            ..self
        }
    }
-
-    /// Whether to enable preview behavior or not.
-    pub fn preview(self, yes: bool) -> DisplayDiagnosticConfig {
-        DisplayDiagnosticConfig {
-            preview: yes,
-            ..self
-        }
-    }
 }

 impl Default for DisplayDiagnosticConfig {
@@ -1216,7 +1002,6 @@ impl Default for DisplayDiagnosticConfig {
            format: DiagnosticFormat::default(),
            color: false,
            context: 2,
-            preview: false,
        }
    }
 }
@@ -1244,21 +1029,6 @@ pub enum DiagnosticFormat {
    ///
    /// This may use color when printing to a `tty`.
    Concise,
-    /// Print diagnostics in the [Azure Pipelines] format.
-    ///
-    /// [Azure Pipelines]: https://learn.microsoft.com/en-us/azure/devops/pipelines/scripts/logging-commands?view=azure-devops&tabs=bash#logissue-log-an-error-or-warning
-    Azure,
-    /// Print diagnostics in JSON format.
-    ///
-    /// Unlike `json-lines`, this prints all of the diagnostics as a JSON array.
-    #[cfg(feature = "serde")]
-    Json,
-    /// Print diagnostics in JSON format, one per line.
-    ///
-    /// This will print each diagnostic as a separate JSON object on its own line. See the `json`
-    /// format for an array of all diagnostics. See <https://jsonlines.org/> for more details.
-    #[cfg(feature = "serde")]
-    JsonLines,
 }

 /// A representation of the kinds of messages inside a diagnostic.
@@ -1377,52 +1147,41 @@ impl<T: std::fmt::Display> IntoDiagnosticMessage for T {
    }
 }

-/// A secondary identifier for a lint diagnostic.
+/// Creates a `Diagnostic` from a parse error.
 ///
-/// For Ruff rules this means the noqa code.
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Default, Hash, get_size2::GetSize)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize), serde(transparent))]
-pub struct SecondaryCode(String);
-
-impl SecondaryCode {
-    pub fn new(code: String) -> Self {
-        Self(code)
-    }
-
-    pub fn as_str(&self) -> &str {
-        &self.0
-    }
+/// This should _probably_ be a method on `ruff_python_parser::ParseError`, but
+/// at time of writing, `ruff_db` depends on `ruff_python_parser` instead of
+/// the other way around. And since we want to do this conversion in a couple
+/// places, it makes sense to centralize it _somewhere_. So it's here for now.
+pub fn create_parse_diagnostic(file: File, err: &ruff_python_parser::ParseError) -> Diagnostic {
+    let mut diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, "");
+    let span = Span::from(file).with_range(err.location);
+    diag.annotate(Annotation::primary(span).message(&err.error));
+    diag
 }

-impl std::fmt::Display for SecondaryCode {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.write_str(&self.0)
-    }
+/// Creates a `Diagnostic` from an unsupported syntax error.
+///
+/// See [`create_parse_diagnostic`] for more details.
+pub fn create_unsupported_syntax_diagnostic(
+    file: File,
+    err: &ruff_python_parser::UnsupportedSyntaxError,
+) -> Diagnostic {
+    let mut diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, "");
+    let span = Span::from(file).with_range(err.range);
+    diag.annotate(Annotation::primary(span).message(err.to_string()));
+    diag
 }

-impl std::ops::Deref for SecondaryCode {
-    type Target = str;
-
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl PartialEq<&str> for SecondaryCode {
-    fn eq(&self, other: &&str) -> bool {
-        self.0 == *other
-    }
-}
-
-impl PartialEq<SecondaryCode> for &str {
-    fn eq(&self, other: &SecondaryCode) -> bool {
-        other.eq(self)
-    }
-}
-
-// for `hashbrown::EntryRef`
-impl From<&SecondaryCode> for SecondaryCode {
-    fn from(value: &SecondaryCode) -> Self {
-        value.clone()
-    }
+/// Creates a `Diagnostic` from a semantic syntax error.
+///
+/// See [`create_parse_diagnostic`] for more details.
+pub fn create_semantic_syntax_diagnostic(
+    file: File,
+    err: &ruff_python_parser::semantic_errors::SemanticSyntaxError,
+) -> Diagnostic {
+    let mut diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, "");
+    let span = Span::from(file).with_range(err.range);
+    diag.annotate(Annotation::primary(span).message(err.to_string()));
+    diag
 }
--- a/crates/ruff_db/src/diagnostic/render.rs
+++ b/crates/ruff_db/src/diagnostic/render.rs
@@ -4,7 +4,6 @@ use ruff_annotate_snippets::{
    Annotation as AnnotateAnnotation, Level as AnnotateLevel, Message as AnnotateMessage,
    Renderer as AnnotateRenderer, Snippet as AnnotateSnippet,
 };
-use ruff_notebook::{Notebook, NotebookIndex};
 use ruff_source_file::{LineIndex, OneIndexed, SourceCode};
 use ruff_text_size::{TextRange, TextSize};

@@ -18,17 +17,9 @@ use crate::{

 use super::{
    Annotation, Diagnostic, DiagnosticFormat, DiagnosticSource, DisplayDiagnosticConfig, Severity,
-    SubDiagnostic, UnifiedFile,
+    SubDiagnostic,
 };

-use azure::AzureRenderer;
-
-mod azure;
-#[cfg(feature = "serde")]
-mod json;
-#[cfg(feature = "serde")]
-mod json_lines;
-
 /// A type that implements `std::fmt::Display` for diagnostic rendering.
 ///
 /// It is created via [`Diagnostic::display`].
@@ -43,6 +34,7 @@ mod json_lines;
 pub struct DisplayDiagnostic<'a> {
    config: &'a DisplayDiagnosticConfig,
    resolver: &'a dyn FileResolver,
+    annotate_renderer: AnnotateRenderer,
    diag: &'a Diagnostic,
 }

@@ -52,9 +44,16 @@ impl<'a> DisplayDiagnostic<'a> {
        config: &'a DisplayDiagnosticConfig,
        diag: &'a Diagnostic,
    ) -> DisplayDiagnostic<'a> {
+        let annotate_renderer = if config.color {
+            AnnotateRenderer::styled()
+        } else {
+            AnnotateRenderer::plain()
+        };
+
        DisplayDiagnostic {
            config,
            resolver,
+            annotate_renderer,
            diag,
        }
    }
@@ -62,131 +61,68 @@ impl<'a> DisplayDiagnostic<'a> {

 impl std::fmt::Display for DisplayDiagnostic<'_> {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        DisplayDiagnostics::new(self.resolver, self.config, std::slice::from_ref(self.diag)).fmt(f)
-    }
-}
+        let stylesheet = if self.config.color {
+            DiagnosticStylesheet::styled()
+        } else {
+            DiagnosticStylesheet::plain()
+        };

-/// A type that implements `std::fmt::Display` for rendering a collection of diagnostics.
-///
-/// It is intended for collections of diagnostics that need to be serialized together, as is the
-/// case for JSON, for example.
-///
-/// See [`DisplayDiagnostic`] for rendering individual `Diagnostic`s and details about the lifetime
-/// constraints.
-pub struct DisplayDiagnostics<'a> {
-    config: &'a DisplayDiagnosticConfig,
-    resolver: &'a dyn FileResolver,
-    diagnostics: &'a [Diagnostic],
-}
+        if matches!(self.config.format, DiagnosticFormat::Concise) {
+            let (severity, severity_style) = match self.diag.severity() {
+                Severity::Info => ("info", stylesheet.info),
+                Severity::Warning => ("warning", stylesheet.warning),
+                Severity::Error => ("error", stylesheet.error),
+                Severity::Fatal => ("fatal", stylesheet.error),
+            };

-impl<'a> DisplayDiagnostics<'a> {
-    pub fn new(
-        resolver: &'a dyn FileResolver,
-        config: &'a DisplayDiagnosticConfig,
-        diagnostics: &'a [Diagnostic],
-    ) -> DisplayDiagnostics<'a> {
-        DisplayDiagnostics {
-            config,
-            resolver,
-            diagnostics,
-        }
-    }
-}
+            write!(
+                f,
+                "{severity}[{id}]",
+                severity = fmt_styled(severity, severity_style),
+                id = fmt_styled(self.diag.id(), stylesheet.emphasis)
+            )?;

-impl std::fmt::Display for DisplayDiagnostics<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        match self.config.format {
-            DiagnosticFormat::Concise => {
-                let stylesheet = if self.config.color {
-                    DiagnosticStylesheet::styled()
-                } else {
-                    DiagnosticStylesheet::plain()
-                };
+            if let Some(span) = self.diag.primary_span() {
+                write!(
+                    f,
+                    " {path}",
+                    path = fmt_styled(span.file().path(self.resolver), stylesheet.emphasis)
+                )?;
+                if let Some(range) = span.range() {
+                    let diagnostic_source = span.file().diagnostic_source(self.resolver);
+                    let start = diagnostic_source
+                        .as_source_code()
+                        .line_column(range.start());

-                for diag in self.diagnostics {
-                    let (severity, severity_style) = match diag.severity() {
-                        Severity::Info => ("info", stylesheet.info),
-                        Severity::Warning => ("warning", stylesheet.warning),
-                        Severity::Error => ("error", stylesheet.error),
-                        Severity::Fatal => ("fatal", stylesheet.error),
-                    };
                    write!(
                        f,
-                        "{severity}[{id}]",
-                        severity = fmt_styled(severity, severity_style),
-                        id = fmt_styled(diag.id(), stylesheet.emphasis)
+                        ":{line}:{col}",
+                        line = fmt_styled(start.line, stylesheet.emphasis),
+                        col = fmt_styled(start.column, stylesheet.emphasis),
                    )?;
-                    if let Some(span) = diag.primary_span() {
-                        write!(
-                            f,
-                            " {path}",
-                            path = fmt_styled(span.file().path(self.resolver), stylesheet.emphasis)
-                        )?;
-                        if let Some(range) = span.range() {
-                            let diagnostic_source = span.file().diagnostic_source(self.resolver);
-                            let start = diagnostic_source
-                                .as_source_code()
-                                .line_column(range.start());
-
-                            write!(
-                                f,
-                                ":{line}:{col}",
-                                line = fmt_styled(start.line, stylesheet.emphasis),
-                                col = fmt_styled(start.column, stylesheet.emphasis),
-                            )?;
-                        }
-                        write!(f, ":")?;
-                    }
-                    writeln!(f, " {message}", message = diag.concise_message())?;
                }
+                write!(f, ":")?;
            }
-            DiagnosticFormat::Full => {
-                let stylesheet = if self.config.color {
-                    DiagnosticStylesheet::styled()
-                } else {
-                    DiagnosticStylesheet::plain()
-                };
-
-                let mut renderer = if self.config.color {
-                    AnnotateRenderer::styled()
-                } else {
-                    AnnotateRenderer::plain()
-                };
-
-                renderer = renderer
-                    .error(stylesheet.error)
-                    .warning(stylesheet.warning)
-                    .info(stylesheet.info)
-                    .note(stylesheet.note)
-                    .help(stylesheet.help)
-                    .line_no(stylesheet.line_no)
-                    .emphasis(stylesheet.emphasis)
-                    .none(stylesheet.none);
-
-                for diag in self.diagnostics {
-                    let resolved = Resolved::new(self.resolver, diag);
-                    let renderable = resolved.to_renderable(self.config.context);
-                    for diag in renderable.diagnostics.iter() {
-                        writeln!(f, "{}", renderer.render(diag.to_annotate()))?;
-                    }
-                    writeln!(f)?;
-                }
-            }
-            DiagnosticFormat::Azure => {
-                AzureRenderer::new(self.resolver).render(f, self.diagnostics)?;
-            }
-            #[cfg(feature = "serde")]
-            DiagnosticFormat::Json => {
-                json::JsonRenderer::new(self.resolver, self.config).render(f, self.diagnostics)?;
-            }
-            #[cfg(feature = "serde")]
-            DiagnosticFormat::JsonLines => {
-                json_lines::JsonLinesRenderer::new(self.resolver, self.config)
-                    .render(f, self.diagnostics)?;
-            }
+            return writeln!(f, " {message}", message = self.diag.concise_message());
        }

-        Ok(())
+        let mut renderer = self.annotate_renderer.clone();
+        renderer = renderer
+            .error(stylesheet.error)
+            .warning(stylesheet.warning)
+            .info(stylesheet.info)
+            .note(stylesheet.note)
+            .help(stylesheet.help)
+            .line_no(stylesheet.line_no)
+            .emphasis(stylesheet.emphasis)
+            .none(stylesheet.none);
+
+        let resolved = Resolved::new(self.resolver, self.diag);
+        let renderable = resolved.to_renderable(self.config.context);
+        for diag in renderable.diagnostics.iter() {
+            writeln!(f, "{}", renderer.render(diag.to_annotate()))?;
+        }
+        writeln!(f)
    }
 }

@@ -699,12 +635,6 @@ pub trait FileResolver {

    /// Returns the input contents associated with the file given.
    fn input(&self, file: File) -> Input;
-
-    /// Returns the [`NotebookIndex`] associated with the file given, if it's a Jupyter notebook.
-    fn notebook_index(&self, file: &UnifiedFile) -> Option<NotebookIndex>;
-
-    /// Returns whether the file given is a Jupyter notebook.
-    fn is_notebook(&self, file: &UnifiedFile) -> bool;
 }

 impl<T> FileResolver for T
@@ -721,25 +651,6 @@ where
            line_index: line_index(self, file),
        }
    }
-
-    fn notebook_index(&self, file: &UnifiedFile) -> Option<NotebookIndex> {
-        match file {
-            UnifiedFile::Ty(file) => self
-                .input(*file)
-                .text
-                .as_notebook()
-                .map(Notebook::index)
-                .cloned(),
-            UnifiedFile::Ruff(_) => unimplemented!("Expected an interned ty file"),
-        }
-    }
-
-    fn is_notebook(&self, file: &UnifiedFile) -> bool {
-        match file {
-            UnifiedFile::Ty(file) => self.input(*file).text.as_notebook().is_some(),
-            UnifiedFile::Ruff(_) => unimplemented!("Expected an interned ty file"),
-        }
-    }
 }

 impl FileResolver for &dyn Db {
@@ -753,25 +664,6 @@ impl FileResolver for &dyn Db {
            line_index: line_index(*self, file),
        }
    }
-
-    fn notebook_index(&self, file: &UnifiedFile) -> Option<NotebookIndex> {
-        match file {
-            UnifiedFile::Ty(file) => self
-                .input(*file)
-                .text
-                .as_notebook()
-                .map(Notebook::index)
-                .cloned(),
-            UnifiedFile::Ruff(_) => unimplemented!("Expected an interned ty file"),
-        }
-    }
-
-    fn is_notebook(&self, file: &UnifiedFile) -> bool {
-        match file {
-            UnifiedFile::Ty(file) => self.input(*file).text.as_notebook().is_some(),
-            UnifiedFile::Ruff(_) => unimplemented!("Expected an interned ty file"),
-        }
-    }
 }

 /// An abstraction over a unit of user input.
@@ -832,9 +724,7 @@ fn relativize_path<'p>(cwd: &SystemPath, path: &'p str) -> &'p str {
 #[cfg(test)]
 mod tests {

-    use ruff_diagnostics::{Edit, Fix};
-
-    use crate::diagnostic::{Annotation, DiagnosticId, SecondaryCode, Severity, Span};
+    use crate::diagnostic::{Annotation, DiagnosticId, Severity, Span};
    use crate::files::system_path_to_file;
    use crate::system::{DbWithWritableSystem, SystemPath};
    use crate::tests::TestDb;
@@ -2231,7 +2121,7 @@ watermelon

    /// A small harness for setting up an environment specifically for testing
    /// diagnostic rendering.
-    pub(super) struct TestEnvironment {
+    struct TestEnvironment {
        db: TestDb,
        config: DisplayDiagnosticConfig,
    }
@@ -2240,7 +2130,7 @@ watermelon
        /// Create a new test harness.
        ///
        /// This uses the default diagnostic rendering configuration.
-        pub(super) fn new() -> TestEnvironment {
+        fn new() -> TestEnvironment {
            TestEnvironment {
                db: TestDb::new(),
                config: DisplayDiagnosticConfig::default(),
@@ -2259,26 +2149,8 @@ watermelon
            self.config = config;
        }

-        /// Set the output format to use in diagnostic rendering.
-        pub(super) fn format(&mut self, format: DiagnosticFormat) {
-            let mut config = std::mem::take(&mut self.config);
-            config = config.format(format);
-            self.config = config;
-        }
-
-        /// Enable preview functionality for diagnostic rendering.
-        #[allow(
-            dead_code,
-            reason = "This is currently only used for JSON but will be needed soon for other formats"
-        )]
-        pub(super) fn preview(&mut self, yes: bool) {
-            let mut config = std::mem::take(&mut self.config);
-            config = config.preview(yes);
-            self.config = config;
-        }
-
        /// Add a file with the given path and contents to this environment.
-        pub(super) fn add(&mut self, path: &str, contents: &str) {
+        fn add(&mut self, path: &str, contents: &str) {
            let path = SystemPath::new(path);
            self.db.write_file(path, contents).unwrap();
        }
@@ -2328,7 +2200,7 @@ watermelon
        /// A convenience function for returning a builder for a diagnostic
        /// with "error" severity and canned values for its identifier
        /// and message.
-        pub(super) fn err(&mut self) -> DiagnosticBuilder<'_> {
+        fn err(&mut self) -> DiagnosticBuilder<'_> {
            self.builder(
                "test-diagnostic",
                Severity::Error,
@@ -2354,12 +2226,6 @@ watermelon
            DiagnosticBuilder { env: self, diag }
        }

-        /// A convenience function for returning a builder for an invalid syntax diagnostic.
-        fn invalid_syntax(&mut self, message: &str) -> DiagnosticBuilder<'_> {
-            let diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, message);
-            DiagnosticBuilder { env: self, diag }
-        }
-
        /// Returns a builder for tersely constructing sub-diagnostics.
        fn sub_builder(&mut self, severity: Severity, message: &str) -> SubDiagnosticBuilder<'_> {
            let subdiag = SubDiagnostic::new(severity, message);
@@ -2369,18 +2235,9 @@ watermelon
        /// Render the given diagnostic into a `String`.
        ///
        /// (This will set the "printed" flag on `Diagnostic`.)
-        pub(super) fn render(&self, diag: &Diagnostic) -> String {
+        fn render(&self, diag: &Diagnostic) -> String {
            diag.display(&self.db, &self.config).to_string()
        }
-
-        /// Render the given diagnostics into a `String`.
-        ///
-        /// See `render` for rendering a single diagnostic.
-        ///
-        /// (This will set the "printed" flag on `Diagnostic`.)
-        pub(super) fn render_diagnostics(&self, diagnostics: &[Diagnostic]) -> String {
-            DisplayDiagnostics::new(&self.db, &self.config, diagnostics).to_string()
-        }
    }

    /// A helper builder for tersely populating a `Diagnostic`.
@@ -2389,14 +2246,14 @@ watermelon
    /// supported by this builder, and this only needs to be done
    /// infrequently, consider doing it more verbosely on `diag`
    /// itself.
-    pub(super) struct DiagnosticBuilder<'e> {
+    struct DiagnosticBuilder<'e> {
        env: &'e mut TestEnvironment,
        diag: Diagnostic,
    }

    impl<'e> DiagnosticBuilder<'e> {
        /// Return the built diagnostic.
-        pub(super) fn build(self) -> Diagnostic {
+        fn build(self) -> Diagnostic {
            self.diag
        }

@@ -2445,25 +2302,6 @@ watermelon
            self.diag.annotate(ann);
            self
        }
-
-        /// Set the secondary code on the diagnostic.
-        fn secondary_code(mut self, secondary_code: &str) -> DiagnosticBuilder<'e> {
-            self.diag
-                .set_secondary_code(SecondaryCode::new(secondary_code.to_string()));
-            self
-        }
-
-        /// Set the fix on the diagnostic.
-        pub(super) fn fix(mut self, fix: Fix) -> DiagnosticBuilder<'e> {
-            self.diag.set_fix(fix);
-            self
-        }
-
-        /// Set the noqa offset on the diagnostic.
-        fn noqa_offset(mut self, noqa_offset: TextSize) -> DiagnosticBuilder<'e> {
-            self.diag.set_noqa_offset(noqa_offset);
-            self
-        }
    }

    /// A helper builder for tersely populating a `SubDiagnostic`.
@@ -2543,199 +2381,4 @@ watermelon
        let offset = TextSize::from(offset.parse::<u32>().unwrap());
        (line_number, Some(offset))
    }
-
-    /// Create Ruff-style diagnostics for testing the various output formats.
-    pub(crate) fn create_diagnostics(
-        format: DiagnosticFormat,
-    ) -> (TestEnvironment, Vec<Diagnostic>) {
-        let mut env = TestEnvironment::new();
-        env.add(
-            "fib.py",
-            r#"import os
-
-
-def fibonacci(n):
-    """Compute the nth number in the Fibonacci sequence."""
-    x = 1
-    if n == 0:
-        return 0
-    elif n == 1:
-        return 1
-    else:
-        return fibonacci(n - 1) + fibonacci(n - 2)
-"#,
-        );
-        env.add("undef.py", r"if a == 1: pass");
-        env.format(format);
-
-        let diagnostics = vec![
-            env.builder("unused-import", Severity::Error, "`os` imported but unused")
-                .primary("fib.py", "1:7", "1:9", "Remove unused import: `os`")
-                .secondary_code("F401")
-                .fix(Fix::unsafe_edit(Edit::range_deletion(TextRange::new(
-                    TextSize::from(0),
-                    TextSize::from(10),
-                ))))
-                .noqa_offset(TextSize::from(7))
-                .build(),
-            env.builder(
-                "unused-variable",
-                Severity::Error,
-                "Local variable `x` is assigned to but never used",
-            )
-            .primary(
-                "fib.py",
-                "6:4",
-                "6:5",
-                "Remove assignment to unused variable `x`",
-            )
-            .secondary_code("F841")
-            .fix(Fix::unsafe_edit(Edit::deletion(
-                TextSize::from(94),
-                TextSize::from(99),
-            )))
-            .noqa_offset(TextSize::from(94))
-            .build(),
-            env.builder("undefined-name", Severity::Error, "Undefined name `a`")
-                .primary("undef.py", "1:3", "1:4", "")
-                .secondary_code("F821")
-                .noqa_offset(TextSize::from(3))
-                .build(),
-        ];
-
-        (env, diagnostics)
-    }
-
-    /// Create Ruff-style syntax error diagnostics for testing the various output formats.
-    pub(crate) fn create_syntax_error_diagnostics(
-        format: DiagnosticFormat,
-    ) -> (TestEnvironment, Vec<Diagnostic>) {
-        let mut env = TestEnvironment::new();
-        env.add(
-            "syntax_errors.py",
-            r"from os import
-
-if call(foo
-    def bar():
-        pass
-",
-        );
-        env.format(format);
-
-        let diagnostics = vec![
-            env.invalid_syntax("SyntaxError: Expected one or more symbol names after import")
-                .primary("syntax_errors.py", "1:14", "1:15", "")
-                .build(),
-            env.invalid_syntax("SyntaxError: Expected ')', found newline")
-                .primary("syntax_errors.py", "3:11", "3:12", "")
-                .build(),
-        ];
-
-        (env, diagnostics)
-    }
-
-    /// Create Ruff-style diagnostics for testing the various output formats for a notebook.
-    #[allow(
-        dead_code,
-        reason = "This is currently only used for JSON but will be needed soon for other formats"
-    )]
-    pub(crate) fn create_notebook_diagnostics(
-        format: DiagnosticFormat,
-    ) -> (TestEnvironment, Vec<Diagnostic>) {
-        let mut env = TestEnvironment::new();
-        env.add(
-            "notebook.ipynb",
-            r##"
-        {
- "cells": [
-  {
-   "cell_type": "code",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# cell 1\n",
-    "import os"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# cell 2\n",
-    "import math\n",
-    "\n",
-    "print('hello world')"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "# cell 3\n",
-    "def foo():\n",
-    "    print()\n",
-    "    x = 1\n"
-   ]
-  }
- ],
- "metadata": {},
- "nbformat": 4,
- "nbformat_minor": 5
-}
-"##,
-        );
-        env.format(format);
-
-        let diagnostics = vec![
-            env.builder("unused-import", Severity::Error, "`os` imported but unused")
-                .primary("notebook.ipynb", "2:7", "2:9", "Remove unused import: `os`")
-                .secondary_code("F401")
-                .fix(Fix::safe_edit(Edit::range_deletion(TextRange::new(
-                    TextSize::from(9),
-                    TextSize::from(19),
-                ))))
-                .noqa_offset(TextSize::from(16))
-                .build(),
-            env.builder(
-                "unused-import",
-                Severity::Error,
-                "`math` imported but unused",
-            )
-            .primary(
-                "notebook.ipynb",
-                "4:7",
-                "4:11",
-                "Remove unused import: `math`",
-            )
-            .secondary_code("F401")
-            .fix(Fix::safe_edit(Edit::range_deletion(TextRange::new(
-                TextSize::from(28),
-                TextSize::from(40),
-            ))))
-            .noqa_offset(TextSize::from(35))
-            .build(),
-            env.builder(
-                "unused-variable",
-                Severity::Error,
-                "Local variable `x` is assigned to but never used",
-            )
-            .primary(
-                "notebook.ipynb",
-                "10:4",
-                "10:5",
-                "Remove assignment to unused variable `x`",
-            )
-            .secondary_code("F841")
-            .fix(Fix::unsafe_edit(Edit::range_deletion(TextRange::new(
-                TextSize::from(94),
-                TextSize::from(104),
-            ))))
-            .noqa_offset(TextSize::from(98))
-            .build(),
-        ];
-
-        (env, diagnostics)
-    }
 }
--- a/crates/ruff_db/src/diagnostic/render/azure.rs
+++ b/crates/ruff_db/src/diagnostic/render/azure.rs
@@ -1,83 +0,0 @@
-use ruff_source_file::LineColumn;
-
-use crate::diagnostic::{Diagnostic, Severity};
-
-use super::FileResolver;
-
-pub(super) struct AzureRenderer<'a> {
-    resolver: &'a dyn FileResolver,
-}
-
-impl<'a> AzureRenderer<'a> {
-    pub(super) fn new(resolver: &'a dyn FileResolver) -> Self {
-        Self { resolver }
-    }
-}
-
-impl AzureRenderer<'_> {
-    pub(super) fn render(
-        &self,
-        f: &mut std::fmt::Formatter,
-        diagnostics: &[Diagnostic],
-    ) -> std::fmt::Result {
-        for diag in diagnostics {
-            let severity = match diag.severity() {
-                Severity::Info | Severity::Warning => "warning",
-                Severity::Error | Severity::Fatal => "error",
-            };
-            write!(f, "##vso[task.logissue type={severity};")?;
-            if let Some(span) = diag.primary_span() {
-                let filename = span.file().path(self.resolver);
-                write!(f, "sourcepath={filename};")?;
-                if let Some(range) = span.range() {
-                    let location = if self.resolver.notebook_index(span.file()).is_some() {
-                        // We can't give a reasonable location for the structured formats,
-                        // so we show one that's clearly a fallback
-                        LineColumn::default()
-                    } else {
-                        span.file()
-                            .diagnostic_source(self.resolver)
-                            .as_source_code()
-                            .line_column(range.start())
-                    };
-                    write!(
-                        f,
-                        "linenumber={line};columnnumber={col};",
-                        line = location.line,
-                        col = location.column,
-                    )?;
-                }
-            }
-            writeln!(
-                f,
-                "{code}]{body}",
-                code = diag
-                    .secondary_code()
-                    .map_or_else(String::new, |code| format!("code={code};")),
-                body = diag.body(),
-            )?;
-        }
-
-        Ok(())
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::diagnostic::{
-        DiagnosticFormat,
-        render::tests::{create_diagnostics, create_syntax_error_diagnostics},
-    };
-
-    #[test]
-    fn output() {
-        let (env, diagnostics) = create_diagnostics(DiagnosticFormat::Azure);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-
-    #[test]
-    fn syntax_errors() {
-        let (env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Azure);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-}
--- a/crates/ruff_db/src/diagnostic/render/json.rs
+++ b/crates/ruff_db/src/diagnostic/render/json.rs
@@ -1,393 +0,0 @@
-use serde::{Serialize, Serializer, ser::SerializeSeq};
-use serde_json::{Value, json};
-
-use ruff_diagnostics::{Applicability, Edit};
-use ruff_notebook::NotebookIndex;
-use ruff_source_file::{LineColumn, OneIndexed};
-use ruff_text_size::Ranged;
-
-use crate::diagnostic::{Diagnostic, DiagnosticSource, DisplayDiagnosticConfig, SecondaryCode};
-
-use super::FileResolver;
-
-pub(super) struct JsonRenderer<'a> {
-    resolver: &'a dyn FileResolver,
-    config: &'a DisplayDiagnosticConfig,
-}
-
-impl<'a> JsonRenderer<'a> {
-    pub(super) fn new(resolver: &'a dyn FileResolver, config: &'a DisplayDiagnosticConfig) -> Self {
-        Self { resolver, config }
-    }
-}
-
-impl JsonRenderer<'_> {
-    pub(super) fn render(
-        &self,
-        f: &mut std::fmt::Formatter,
-        diagnostics: &[Diagnostic],
-    ) -> std::fmt::Result {
-        write!(
-            f,
-            "{:#}",
-            diagnostics_to_json_value(diagnostics, self.resolver, self.config)
-        )
-    }
-}
-
-fn diagnostics_to_json_value<'a>(
-    diagnostics: impl IntoIterator<Item = &'a Diagnostic>,
-    resolver: &dyn FileResolver,
-    config: &DisplayDiagnosticConfig,
-) -> Value {
-    let values: Vec<_> = diagnostics
-        .into_iter()
-        .map(|diag| diagnostic_to_json(diag, resolver, config))
-        .collect();
-    json!(values)
-}
-
-pub(super) fn diagnostic_to_json<'a>(
-    diagnostic: &'a Diagnostic,
-    resolver: &'a dyn FileResolver,
-    config: &'a DisplayDiagnosticConfig,
-) -> JsonDiagnostic<'a> {
-    let span = diagnostic.primary_span_ref();
-    let filename = span.map(|span| span.file().path(resolver));
-    let range = span.and_then(|span| span.range());
-    let diagnostic_source = span.map(|span| span.file().diagnostic_source(resolver));
-    let source_code = diagnostic_source
-        .as_ref()
-        .map(|diagnostic_source| diagnostic_source.as_source_code());
-    let notebook_index = span.and_then(|span| resolver.notebook_index(span.file()));
-
-    let mut start_location = None;
-    let mut end_location = None;
-    let mut noqa_location = None;
-    let mut notebook_cell_index = None;
-    if let Some(source_code) = source_code {
-        noqa_location = diagnostic
-            .noqa_offset()
-            .map(|offset| source_code.line_column(offset));
-        if let Some(range) = range {
-            let mut start = source_code.line_column(range.start());
-            let mut end = source_code.line_column(range.end());
-            if let Some(notebook_index) = &notebook_index {
-                notebook_cell_index =
-                    Some(notebook_index.cell(start.line).unwrap_or(OneIndexed::MIN));
-                start = notebook_index.translate_line_column(&start);
-                end = notebook_index.translate_line_column(&end);
-                noqa_location =
-                    noqa_location.map(|location| notebook_index.translate_line_column(&location));
-            }
-            start_location = Some(start);
-            end_location = Some(end);
-        }
-    }
-
-    let fix = diagnostic.fix().map(|fix| JsonFix {
-        applicability: fix.applicability(),
-        message: diagnostic.suggestion(),
-        edits: ExpandedEdits {
-            edits: fix.edits(),
-            notebook_index,
-            config,
-            diagnostic_source,
-        },
-    });
-
-    // In preview, the locations and filename can be optional.
-    if config.preview {
-        JsonDiagnostic {
-            code: diagnostic.secondary_code(),
-            url: diagnostic.to_ruff_url(),
-            message: diagnostic.body(),
-            fix,
-            cell: notebook_cell_index,
-            location: start_location.map(JsonLocation::from),
-            end_location: end_location.map(JsonLocation::from),
-            filename,
-            noqa_row: noqa_location.map(|location| location.line),
-        }
-    } else {
-        JsonDiagnostic {
-            code: diagnostic.secondary_code(),
-            url: diagnostic.to_ruff_url(),
-            message: diagnostic.body(),
-            fix,
-            cell: notebook_cell_index,
-            location: Some(start_location.unwrap_or_default().into()),
-            end_location: Some(end_location.unwrap_or_default().into()),
-            filename: Some(filename.unwrap_or_default()),
-            noqa_row: noqa_location.map(|location| location.line),
-        }
-    }
-}
-
-struct ExpandedEdits<'a> {
-    edits: &'a [Edit],
-    notebook_index: Option<NotebookIndex>,
-    config: &'a DisplayDiagnosticConfig,
-    diagnostic_source: Option<DiagnosticSource>,
-}
-
-impl Serialize for ExpandedEdits<'_> {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        let mut s = serializer.serialize_seq(Some(self.edits.len()))?;
-
-        for edit in self.edits {
-            let (location, end_location) = if let Some(diagnostic_source) = &self.diagnostic_source
-            {
-                let source_code = diagnostic_source.as_source_code();
-                let mut location = source_code.line_column(edit.start());
-                let mut end_location = source_code.line_column(edit.end());
-
-                if let Some(notebook_index) = &self.notebook_index {
-                    // There exists a newline between each cell's source code in the
-                    // concatenated source code in Ruff. This newline doesn't actually
-                    // exists in the JSON source field.
-                    //
-                    // Now, certain edits may try to remove this newline, which means
-                    // the edit will spill over to the first character of the next cell.
-                    // If it does, we need to translate the end location to the last
-                    // character of the previous cell.
-                    match (
-                        notebook_index.cell(location.line),
-                        notebook_index.cell(end_location.line),
-                    ) {
-                        (Some(start_cell), Some(end_cell)) if start_cell != end_cell => {
-                            debug_assert_eq!(end_location.column.get(), 1);
-
-                            let prev_row = end_location.line.saturating_sub(1);
-                            end_location = LineColumn {
-                                line: notebook_index.cell_row(prev_row).unwrap_or(OneIndexed::MIN),
-                                column: source_code
-                                    .line_column(source_code.line_end_exclusive(prev_row))
-                                    .column,
-                            };
-                        }
-                        (Some(_), None) => {
-                            debug_assert_eq!(end_location.column.get(), 1);
-
-                            let prev_row = end_location.line.saturating_sub(1);
-                            end_location = LineColumn {
-                                line: notebook_index.cell_row(prev_row).unwrap_or(OneIndexed::MIN),
-                                column: source_code
-                                    .line_column(source_code.line_end_exclusive(prev_row))
-                                    .column,
-                            };
-                        }
-                        _ => {
-                            end_location = notebook_index.translate_line_column(&end_location);
-                        }
-                    }
-                    location = notebook_index.translate_line_column(&location);
-                }
-
-                (Some(location), Some(end_location))
-            } else {
-                (None, None)
-            };
-
-            // In preview, the locations can be optional.
-            let value = if self.config.preview {
-                JsonEdit {
-                    content: edit.content().unwrap_or_default(),
-                    location: location.map(JsonLocation::from),
-                    end_location: end_location.map(JsonLocation::from),
-                }
-            } else {
-                JsonEdit {
-                    content: edit.content().unwrap_or_default(),
-                    location: Some(location.unwrap_or_default().into()),
-                    end_location: Some(end_location.unwrap_or_default().into()),
-                }
-            };
-
-            s.serialize_element(&value)?;
-        }
-
-        s.end()
-    }
-}
-
-/// A serializable version of `Diagnostic`.
-///
-/// The `Old` variant only exists to preserve backwards compatibility. Both this and `JsonEdit`
-/// should become structs with the `New` definitions in a future Ruff release.
-#[derive(Serialize)]
-pub(crate) struct JsonDiagnostic<'a> {
-    cell: Option<OneIndexed>,
-    code: Option<&'a SecondaryCode>,
-    end_location: Option<JsonLocation>,
-    filename: Option<&'a str>,
-    fix: Option<JsonFix<'a>>,
-    location: Option<JsonLocation>,
-    message: &'a str,
-    noqa_row: Option<OneIndexed>,
-    url: Option<String>,
-}
-
-#[derive(Serialize)]
-struct JsonFix<'a> {
-    applicability: Applicability,
-    edits: ExpandedEdits<'a>,
-    message: Option<&'a str>,
-}
-
-#[derive(Serialize)]
-struct JsonLocation {
-    column: OneIndexed,
-    row: OneIndexed,
-}
-
-impl From<LineColumn> for JsonLocation {
-    fn from(location: LineColumn) -> Self {
-        JsonLocation {
-            row: location.line,
-            column: location.column,
-        }
-    }
-}
-
-#[derive(Serialize)]
-struct JsonEdit<'a> {
-    content: &'a str,
-    end_location: Option<JsonLocation>,
-    location: Option<JsonLocation>,
-}
-
-#[cfg(test)]
-mod tests {
-    use ruff_diagnostics::{Edit, Fix};
-    use ruff_text_size::TextSize;
-
-    use crate::diagnostic::{
-        DiagnosticFormat,
-        render::tests::{
-            TestEnvironment, create_diagnostics, create_notebook_diagnostics,
-            create_syntax_error_diagnostics,
-        },
-    };
-
-    #[test]
-    fn output() {
-        let (env, diagnostics) = create_diagnostics(DiagnosticFormat::Json);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-
-    #[test]
-    fn syntax_errors() {
-        let (env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::Json);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-
-    #[test]
-    fn notebook_output() {
-        let (env, diagnostics) = create_notebook_diagnostics(DiagnosticFormat::Json);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-
-    #[test]
-    fn missing_file_stable() {
-        let mut env = TestEnvironment::new();
-        env.format(DiagnosticFormat::Json);
-        env.preview(false);
-
-        let diag = env
-            .err()
-            .fix(Fix::safe_edit(Edit::insertion(
-                "edit".to_string(),
-                TextSize::from(0),
-            )))
-            .build();
-
-        insta::assert_snapshot!(
-            env.render(&diag),
-            @r#"
-        [
-          {
-            "cell": null,
-            "code": null,
-            "end_location": {
-              "column": 1,
-              "row": 1
-            },
-            "filename": "",
-            "fix": {
-              "applicability": "safe",
-              "edits": [
-                {
-                  "content": "edit",
-                  "end_location": {
-                    "column": 1,
-                    "row": 1
-                  },
-                  "location": {
-                    "column": 1,
-                    "row": 1
-                  }
-                }
-              ],
-              "message": null
-            },
-            "location": {
-              "column": 1,
-              "row": 1
-            },
-            "message": "main diagnostic message",
-            "noqa_row": null,
-            "url": "https://docs.astral.sh/ruff/rules/test-diagnostic"
-          }
-        ]
-        "#,
-        );
-    }
-
-    #[test]
-    fn missing_file_preview() {
-        let mut env = TestEnvironment::new();
-        env.format(DiagnosticFormat::Json);
-        env.preview(true);
-
-        let diag = env
-            .err()
-            .fix(Fix::safe_edit(Edit::insertion(
-                "edit".to_string(),
-                TextSize::from(0),
-            )))
-            .build();
-
-        insta::assert_snapshot!(
-            env.render(&diag),
-            @r#"
-        [
-          {
-            "cell": null,
-            "code": null,
-            "end_location": null,
-            "filename": null,
-            "fix": {
-              "applicability": "safe",
-              "edits": [
-                {
-                  "content": "edit",
-                  "end_location": null,
-                  "location": null
-                }
-              ],
-              "message": null
-            },
-            "location": null,
-            "message": "main diagnostic message",
-            "noqa_row": null,
-            "url": "https://docs.astral.sh/ruff/rules/test-diagnostic"
-          }
-        ]
-        "#,
-        );
-    }
-}
--- a/crates/ruff_db/src/diagnostic/render/json_lines.rs
+++ b/crates/ruff_db/src/diagnostic/render/json_lines.rs
@@ -1,59 +0,0 @@
-use crate::diagnostic::{Diagnostic, DisplayDiagnosticConfig, render::json::diagnostic_to_json};
-
-use super::FileResolver;
-
-pub(super) struct JsonLinesRenderer<'a> {
-    resolver: &'a dyn FileResolver,
-    config: &'a DisplayDiagnosticConfig,
-}
-
-impl<'a> JsonLinesRenderer<'a> {
-    pub(super) fn new(resolver: &'a dyn FileResolver, config: &'a DisplayDiagnosticConfig) -> Self {
-        Self { resolver, config }
-    }
-}
-
-impl JsonLinesRenderer<'_> {
-    pub(super) fn render(
-        &self,
-        f: &mut std::fmt::Formatter,
-        diagnostics: &[Diagnostic],
-    ) -> std::fmt::Result {
-        for diag in diagnostics {
-            writeln!(
-                f,
-                "{}",
-                serde_json::json!(diagnostic_to_json(diag, self.resolver, self.config))
-            )?;
-        }
-
-        Ok(())
-    }
-}
-#[cfg(test)]
-mod tests {
-    use crate::diagnostic::{
-        DiagnosticFormat,
-        render::tests::{
-            create_diagnostics, create_notebook_diagnostics, create_syntax_error_diagnostics,
-        },
-    };
-
-    #[test]
-    fn output() {
-        let (env, diagnostics) = create_diagnostics(DiagnosticFormat::JsonLines);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-
-    #[test]
-    fn syntax_errors() {
-        let (env, diagnostics) = create_syntax_error_diagnostics(DiagnosticFormat::JsonLines);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-
-    #[test]
-    fn notebook_output() {
-        let (env, diagnostics) = create_notebook_diagnostics(DiagnosticFormat::JsonLines);
-        insta::assert_snapshot!(env.render_diagnostics(&diagnostics));
-    }
-}
--- a/crates/ruff_db/src/lib.rs
+++ b/crates/ruff_db/src/lib.rs
@@ -5,7 +5,6 @@ use ruff_python_ast::PythonVersion;
 use rustc_hash::FxHasher;
 use std::hash::BuildHasherDefault;
 use std::num::NonZeroUsize;
-use ty_static::EnvVars;

 pub mod diagnostic;
 pub mod display;
@@ -51,8 +50,8 @@ pub trait Db: salsa::Database {
 /// ty can still spawn more threads for other tasks, e.g. to wait for a Ctrl+C signal or
 /// watching the files for changes.
 pub fn max_parallelism() -> NonZeroUsize {
-    std::env::var(EnvVars::TY_MAX_PARALLELISM)
-        .or_else(|_| std::env::var(EnvVars::RAYON_NUM_THREADS))
+    std::env::var("TY_MAX_PARALLELISM")
+        .or_else(|_| std::env::var("RAYON_NUM_THREADS"))
        .ok()
        .and_then(|s| s.parse().ok())
        .unwrap_or_else(|| {
--- a/crates/ruff_db/src/vendored.rs
+++ b/crates/ruff_db/src/vendored.rs
@@ -21,19 +21,6 @@ type LockedZipArchive<'a> = MutexGuard<'a, VendoredZipArchive>;
 ///
 /// "Files" in the `VendoredFileSystem` are read-only and immutable.
 /// Directories are supported, but symlinks and hardlinks cannot exist.
-///
-/// # Path separators
-///
-/// At time of writing (2025-07-11), this implementation always uses `/` as a
-/// path separator, even in Windows environments where `\` is traditionally
-/// used as a file path separator. Namely, this is only currently used with zip
-/// files built by `crates/ty_vendored/build.rs`.
-///
-/// Callers using this may provide paths that use a `\` as a separator. It will
-/// be transparently normalized to `/`.
-///
-/// This is particularly important because the presence of a trailing separator
-/// in a zip file is conventionally used to indicate a directory entry.
 #[derive(Clone)]
 pub struct VendoredFileSystem {
    inner: Arc<Mutex<VendoredZipArchive>>,
@@ -128,68 +115,6 @@ impl VendoredFileSystem {
        read_to_string(self, path.as_ref())
    }

-    /// Read the direct children of the directory
-    /// identified by `path`.
-    ///
-    /// If `path` is not a directory, then this will
-    /// return an empty `Vec`.
-    pub fn read_directory(&self, dir: impl AsRef<VendoredPath>) -> Vec<DirectoryEntry> {
-        // N.B. We specifically do not return an iterator here to avoid
-        // holding a lock for the lifetime of the iterator returned.
-        // That is, it seems like a footgun to keep the zip archive
-        // locked during iteration, since the unit of work for each
-        // item in the iterator could be arbitrarily long. Allocating
-        // up front and stuffing all entries into it is probably the
-        // simplest solution and what we do here. If this becomes
-        // a problem, there are other strategies we could pursue.
-        // (Amortizing allocs, using a different synchronization
-        // behavior or even exposing additional APIs.) ---AG
-
-        fn read_directory(fs: &VendoredFileSystem, dir: &VendoredPath) -> Vec<DirectoryEntry> {
-            let mut normalized = NormalizedVendoredPath::from(dir);
-            if !normalized.as_str().ends_with('/') {
-                normalized = normalized.with_trailing_slash();
-            }
-            let archive = fs.lock_archive();
-            let mut entries = vec![];
-            for name in archive.0.file_names() {
-                // Any entry that doesn't have the `path` (with a
-                // trailing slash) as a prefix cannot possibly be in
-                // the directory referenced by `path`.
-                let Some(without_dir_prefix) = name.strip_prefix(normalized.as_str()) else {
-                    continue;
-                };
-                // Filter out an entry equivalent to the path given
-                // since we only want children of the directory.
-                if without_dir_prefix.is_empty() {
-                    continue;
-                }
-                // We only want *direct* children. Files that are
-                // direct children cannot have any slashes (or else
-                // they are not direct children). Directories that
-                // are direct children can only have one slash and
-                // it must be at the end.
-                //
-                // (We do this manually ourselves to avoid doing a
-                // full file lookup and metadata retrieval via the
-                // `zip` crate.)
-                let file_type = FileType::from_zip_file_name(without_dir_prefix);
-                let slash_count = without_dir_prefix.matches('/').count();
-                match file_type {
-                    FileType::File if slash_count > 0 => continue,
-                    FileType::Directory if slash_count > 1 => continue,
-                    _ => {}
-                }
-                entries.push(DirectoryEntry {
-                    path: VendoredPathBuf::from(name),
-                    file_type,
-                });
-            }
-            entries
-        }
-        read_directory(self, dir.as_ref())
-    }
-
    /// Acquire a lock on the underlying zip archive.
    /// The call will block until it is able to acquire the lock.
    ///
@@ -281,14 +206,6 @@ pub enum FileType {
 }

 impl FileType {
-    fn from_zip_file_name(name: &str) -> FileType {
-        if name.ends_with('/') {
-            FileType::Directory
-        } else {
-            FileType::File
-        }
-    }
-
    pub const fn is_file(self) -> bool {
        matches!(self, Self::File)
    }
@@ -327,30 +244,6 @@ impl Metadata {
    }
 }

-#[derive(Debug, PartialEq, Eq)]
-pub struct DirectoryEntry {
-    path: VendoredPathBuf,
-    file_type: FileType,
-}
-
-impl DirectoryEntry {
-    pub fn new(path: VendoredPathBuf, file_type: FileType) -> Self {
-        Self { path, file_type }
-    }
-
-    pub fn into_path(self) -> VendoredPathBuf {
-        self.path
-    }
-
-    pub fn path(&self) -> &VendoredPath {
-        &self.path
-    }
-
-    pub fn file_type(&self) -> FileType {
-        self.file_type
-    }
-}
-
 /// Newtype wrapper around a ZipArchive.
 #[derive(Debug)]
 struct VendoredZipArchive(ZipArchive<io::Cursor<Cow<'static, [u8]>>>);
@@ -605,60 +498,6 @@ pub(crate) mod tests {
        test_directory("./stdlib/asyncio/../asyncio/")
    }

-    fn readdir_snapshot(fs: &VendoredFileSystem, path: &str) -> String {
-        let mut paths = fs
-            .read_directory(VendoredPath::new(path))
-            .into_iter()
-            .map(|entry| entry.path().to_string())
-            .collect::<Vec<String>>();
-        paths.sort();
-        paths.join("\n")
-    }
-
-    #[test]
-    fn read_directory_stdlib() {
-        let mock_typeshed = mock_typeshed();
-
-        assert_snapshot!(readdir_snapshot(&mock_typeshed, "stdlib"), @r"
-        vendored://stdlib/asyncio/
-        vendored://stdlib/functools.pyi
-        ");
-        assert_snapshot!(readdir_snapshot(&mock_typeshed, "stdlib/"), @r"
-        vendored://stdlib/asyncio/
-        vendored://stdlib/functools.pyi
-        ");
-        assert_snapshot!(readdir_snapshot(&mock_typeshed, "./stdlib"), @r"
-        vendored://stdlib/asyncio/
-        vendored://stdlib/functools.pyi
-        ");
-        assert_snapshot!(readdir_snapshot(&mock_typeshed, "./stdlib/"), @r"
-        vendored://stdlib/asyncio/
-        vendored://stdlib/functools.pyi
-        ");
-    }
-
-    #[test]
-    fn read_directory_asyncio() {
-        let mock_typeshed = mock_typeshed();
-
-        assert_snapshot!(
-            readdir_snapshot(&mock_typeshed, "stdlib/asyncio"),
-            @"vendored://stdlib/asyncio/tasks.pyi",
-        );
-        assert_snapshot!(
-            readdir_snapshot(&mock_typeshed, "./stdlib/asyncio"),
-            @"vendored://stdlib/asyncio/tasks.pyi",
-        );
-        assert_snapshot!(
-            readdir_snapshot(&mock_typeshed, "stdlib/asyncio/"),
-            @"vendored://stdlib/asyncio/tasks.pyi",
-        );
-        assert_snapshot!(
-            readdir_snapshot(&mock_typeshed, "./stdlib/asyncio/"),
-            @"vendored://stdlib/asyncio/tasks.pyi",
-        );
-    }
-
    fn test_nonexistent_path(path: &str) {
        let mock_typeshed = mock_typeshed();
        let path = VendoredPath::new(path);
--- a/crates/ruff_db/src/vendored/path.rs
+++ b/crates/ruff_db/src/vendored/path.rs
@@ -17,10 +17,6 @@ impl VendoredPath {
        unsafe { &*(path as *const Utf8Path as *const VendoredPath) }
    }

-    pub fn file_name(&self) -> Option<&str> {
-        self.0.file_name()
-    }
-
    pub fn to_path_buf(&self) -> VendoredPathBuf {
        VendoredPathBuf(self.0.to_path_buf())
    }
--- a/crates/ruff_dev/Cargo.toml
+++ b/crates/ruff_dev/Cargo.toml
@@ -13,7 +13,6 @@ license = { workspace = true }
 [dependencies]
 ty = { workspace = true }
 ty_project = { workspace = true, features = ["schemars"] }
-ty_static = { workspace = true }
 ruff = { workspace = true }
 ruff_formatter = { workspace = true }
 ruff_linter = { workspace = true, features = ["schemars"] }
--- a/crates/ruff_dev/src/generate_all.rs
+++ b/crates/ruff_dev/src/generate_all.rs
@@ -4,7 +4,7 @@ use anyhow::Result;

 use crate::{
    generate_cli_help, generate_docs, generate_json_schema, generate_ty_cli_reference,
-    generate_ty_env_vars_reference, generate_ty_options, generate_ty_rules, generate_ty_schema,
+    generate_ty_options, generate_ty_rules, generate_ty_schema,
 };

 pub(crate) const REGENERATE_ALL_COMMAND: &str = "cargo dev generate-all";
@@ -44,8 +44,5 @@ pub(crate) fn main(args: &Args) -> Result<()> {
    generate_ty_options::main(&generate_ty_options::Args { mode: args.mode })?;
    generate_ty_rules::main(&generate_ty_rules::Args { mode: args.mode })?;
    generate_ty_cli_reference::main(&generate_ty_cli_reference::Args { mode: args.mode })?;
-    generate_ty_env_vars_reference::main(&generate_ty_env_vars_reference::Args {
-        mode: args.mode,
-    })?;
    Ok(())
 }
--- a/crates/ruff_dev/src/generate_ty_env_vars_reference.rs
+++ b/crates/ruff_dev/src/generate_ty_env_vars_reference.rs
@@ -1,119 +0,0 @@
-//! Generate the environment variables reference from `ty_static::EnvVars`.
-
-use std::collections::BTreeSet;
-use std::fs;
-use std::path::PathBuf;
-
-use anyhow::bail;
-use pretty_assertions::StrComparison;
-
-use ty_static::EnvVars;
-
-use crate::generate_all::Mode;
-
-#[derive(clap::Args)]
-pub(crate) struct Args {
-    #[arg(long, default_value_t, value_enum)]
-    pub(crate) mode: Mode,
-}
-
-pub(crate) fn main(args: &Args) -> anyhow::Result<()> {
-    let reference_string = generate();
-    let filename = "environment.md";
-    let reference_path = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .parent()
-        .unwrap()
-        .parent()
-        .unwrap()
-        .join("crates")
-        .join("ty")
-        .join("docs")
-        .join(filename);
-
-    match args.mode {
-        Mode::DryRun => {
-            println!("{reference_string}");
-        }
-        Mode::Check => match fs::read_to_string(&reference_path) {
-            Ok(current) => {
-                if current == reference_string {
-                    println!("Up-to-date: {filename}");
-                } else {
-                    let comparison = StrComparison::new(&current, &reference_string);
-                    bail!(
-                        "{filename} changed, please run `cargo dev generate-ty-env-vars-reference`:\n{comparison}"
-                    );
-                }
-            }
-            Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
-                bail!(
-                    "{filename} not found, please run `cargo dev generate-ty-env-vars-reference`"
-                );
-            }
-            Err(err) => {
-                bail!(
-                    "{filename} changed, please run `cargo dev generate-ty-env-vars-reference`:\n{err}"
-                );
-            }
-        },
-        Mode::Write => {
-            // Ensure the docs directory exists
-            if let Some(parent) = reference_path.parent() {
-                fs::create_dir_all(parent)?;
-            }
-
-            match fs::read_to_string(&reference_path) {
-                Ok(current) => {
-                    if current == reference_string {
-                        println!("Up-to-date: {filename}");
-                    } else {
-                        println!("Updating: {filename}");
-                        fs::write(&reference_path, reference_string.as_bytes())?;
-                    }
-                }
-                Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
-                    println!("Updating: {filename}");
-                    fs::write(&reference_path, reference_string.as_bytes())?;
-                }
-                Err(err) => {
-                    bail!(
-                        "{filename} changed, please run `cargo dev generate-ty-env-vars-reference`:\n{err}"
-                    );
-                }
-            }
-        }
-    }
-
-    Ok(())
-}
-
-fn generate() -> String {
-    let mut output = String::new();
-
-    output.push_str("# Environment variables\n\n");
-
-    // Partition and sort environment variables into TY_ and external variables.
-    let (ty_vars, external_vars): (BTreeSet<_>, BTreeSet<_>) = EnvVars::metadata()
-        .iter()
-        .partition(|(var, _)| var.starts_with("TY_"));
-
-    output.push_str("ty defines and respects the following environment variables:\n\n");
-
-    for (var, doc) in ty_vars {
-        output.push_str(&render(var, doc));
-    }
-
-    output.push_str("## Externally-defined variables\n\n");
-    output.push_str("ty also reads the following externally defined environment variables:\n\n");
-
-    for (var, doc) in external_vars {
-        output.push_str(&render(var, doc));
-    }
-
-    output
-}
-
-/// Render an environment variable and its documentation.
-fn render(var: &str, doc: &str) -> String {
-    format!("### `{var}`\n\n{doc}\n\n")
-}
--- a/crates/ruff_dev/src/main.rs
+++ b/crates/ruff_dev/src/main.rs
@@ -18,7 +18,6 @@ mod generate_json_schema;
 mod generate_options;
 mod generate_rules_table;
 mod generate_ty_cli_reference;
-mod generate_ty_env_vars_reference;
 mod generate_ty_options;
 mod generate_ty_rules;
 mod generate_ty_schema;
@@ -54,8 +53,6 @@ enum Command {
    /// Generate a Markdown-compatible listing of configuration options.
    GenerateOptions,
    GenerateTyOptions(generate_ty_options::Args),
-    /// Generate environment variables reference for ty.
-    GenerateTyEnvVarsReference(generate_ty_env_vars_reference::Args),
    /// Generate CLI help.
    GenerateCliHelp(generate_cli_help::Args),
    /// Generate Markdown docs.
@@ -101,7 +98,6 @@ fn main() -> Result<ExitCode> {
        Command::GenerateTyRules(args) => generate_ty_rules::main(&args)?,
        Command::GenerateOptions => println!("{}", generate_options::generate()),
        Command::GenerateTyOptions(args) => generate_ty_options::main(&args)?,
-        Command::GenerateTyEnvVarsReference(args) => generate_ty_env_vars_reference::main(&args)?,
        Command::GenerateCliHelp(args) => generate_cli_help::main(&args)?,
        Command::GenerateDocs(args) => generate_docs::main(&args)?,
        Command::PrintAST(args) => print_ast::main(&args)?,
--- a/crates/ruff_diagnostics/Cargo.toml
+++ b/crates/ruff_diagnostics/Cargo.toml
@@ -16,6 +16,5 @@ doctest = false
 [dependencies]
 ruff_text_size = { workspace = true }

-get-size2 = { workspace = true }
 is-macro = { workspace = true }
 serde = { workspace = true, optional = true, features = [] }
--- a/crates/ruff_diagnostics/src/edit.rs
+++ b/crates/ruff_diagnostics/src/edit.rs
@@ -7,7 +7,7 @@ use ruff_text_size::{Ranged, TextRange, TextSize};

 /// A text edit to be applied to a source file. Inserts, deletes, or replaces
 /// content at a given location.
-#[derive(Clone, Debug, PartialEq, Eq, Hash, get_size2::GetSize)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Edit {
    /// The start location of the edit.
--- a/crates/ruff_diagnostics/src/fix.rs
+++ b/crates/ruff_diagnostics/src/fix.rs
@@ -6,9 +6,7 @@ use ruff_text_size::{Ranged, TextSize};
 use crate::edit::Edit;

 /// Indicates if a fix can be applied.
-#[derive(
-    Copy, Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord, is_macro::Is, get_size2::GetSize,
-)]
+#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord, is_macro::Is)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "serde", serde(rename_all = "lowercase"))]
 pub enum Applicability {
@@ -32,7 +30,7 @@ pub enum Applicability {
 }

 /// Indicates the level of isolation required to apply a fix.
-#[derive(Default, Copy, Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord, get_size2::GetSize)]
+#[derive(Default, Copy, Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum IsolationLevel {
    /// The fix should be applied as long as no other fixes in the same group have been applied.
@@ -43,7 +41,7 @@ pub enum IsolationLevel {
 }

 /// A collection of [`Edit`] elements to be applied to a source file.
-#[derive(Debug, PartialEq, Eq, Clone, get_size2::GetSize)]
+#[derive(Debug, PartialEq, Eq, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Fix {
    /// The [`Edit`] elements to be applied, sorted by [`Edit::start`] in ascending order.
--- a/crates/ruff_linter/Cargo.toml
+++ b/crates/ruff_linter/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ruff_linter"
-version = "0.12.3"
+version = "0.12.1"
 publish = false
 authors = { workspace = true }
 edition = { workspace = true }
@@ -15,7 +15,7 @@ license = { workspace = true }
 [dependencies]
 ruff_annotate_snippets = { workspace = true }
 ruff_cache = { workspace = true }
-ruff_db = { workspace = true, features = ["serde"] }
+ruff_db = { workspace = true }
 ruff_diagnostics = { workspace = true, features = ["serde"] }
 ruff_notebook = { workspace = true }
 ruff_macros = { workspace = true }
--- a/crates/ruff_linter/resources/test/fixtures/flake8_bandit/S112.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_bandit/S112.py
@@ -1,30 +1,29 @@
-for _ in []:
-    try:
-        pass
-    except Exception:
-        continue
+try:
+    pass
+except Exception:
+    continue

-    try:
-        pass
-    except:
-        continue
+try:
+    pass
+except:
+    continue

-    try:
-        pass
-    except (Exception,):
-        continue
+try:
+    pass
+except (Exception,):
+    continue

-    try:
-        pass
-    except (Exception, ValueError):
-        continue
+try:
+    pass
+except (Exception, ValueError):
+    continue

-    try:
-        pass
-    except ValueError:
-        continue
+try:
+    pass
+except ValueError:
+    continue

-    try:
-        pass
-    except (ValueError,):
-        continue
+try:
+    pass
+except (ValueError,):
+    continue
--- a/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B017_0.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B017_0.py
@@ -1,10 +1,10 @@
 """
 Should emit:
-B017 - on lines 24, 28, 46, 49, 52, 58, 62, 68, and 71
+B017 - on lines 23 and 41
 """
 import asyncio
 import unittest
-import pytest, contextlib
+import pytest

 CONSTANT = True

@@ -56,17 +56,3 @@ def test_pytest_raises():

    with contextlib.nullcontext(), pytest.raises(Exception):
        raise ValueError("Multiple context managers")
-
-
-def test_pytest_raises_keyword():
-    with pytest.raises(expected_exception=Exception):
-        raise ValueError("Should be flagged")
-
-def test_assert_raises_keyword():
-    class TestKwargs(unittest.TestCase):
-        def test_method(self):
-            with self.assertRaises(exception=Exception):
-                raise ValueError("Should be flagged")
-
-            with self.assertRaises(exception=BaseException):
-                raise ValueError("Should be flagged")
--- a/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B017_1.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B017_1.py
@@ -1,28 +0,0 @@
-"""
-Should emit:
-B017 - on lines 20, 21, 25, and 26
-"""
-import unittest
-import pytest
-
-
-def something_else() -> None:
-    for i in (1, 2, 3):
-        print(i)
-
-
-class Foo:
-    pass
-
-
-class Foobar(unittest.TestCase):
-    def call_form_raises(self) -> None:
-        self.assertRaises(Exception, something_else)
-        self.assertRaises(BaseException, something_else)
-
-
-def test_pytest_call_form() -> None:
-    pytest.raises(Exception, something_else)
-    pytest.raises(BaseException, something_else)
-
-    pytest.raises(Exception, something_else, match="hello")
--- a/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B031.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B031.py
@@ -185,45 +185,38 @@ for _section, section_items in groupby(items, key=lambda p: p[1]):
    collect_shop_items(shopper, section_items)

 # Shouldn't trigger the warning when there is a return statement.
-def foo():
-    for _section, section_items in groupby(items, key=lambda p: p[1]):
-        if _section == "greens":
-            collect_shop_items(shopper, section_items)
-            return
-        elif _section == "frozen items":
-            return section_items
+for _section, section_items in groupby(items, key=lambda p: p[1]):
+    if _section == "greens":
        collect_shop_items(shopper, section_items)
+        return
+    elif _section == "frozen items":
+        return section_items
+    collect_shop_items(shopper, section_items)

 # Should trigger the warning for duplicate access, even if is a return statement after.
-def foo():
-    from itertools import groupby
-    for _section, section_items in groupby(items, key=lambda p: p[1]):
-        if _section == "greens":
-            collect_shop_items(shopper, section_items)
-            collect_shop_items(shopper, section_items)
-            return
+for _section, section_items in groupby(items, key=lambda p: p[1]):
+    if _section == "greens":
+        collect_shop_items(shopper, section_items)
+        collect_shop_items(shopper, section_items)
+        return

 # Should trigger the warning for duplicate access, even if is a return in another branch.
-def foo():
-    from itertools import groupby
-    for _section, section_items in groupby(items, key=lambda p: p[1]):
-        if _section == "greens":
-            collect_shop_items(shopper, section_items)
-            return
-        elif _section == "frozen items":
-            collect_shop_items(shopper, section_items)
-            collect_shop_items(shopper, section_items)
+for _section, section_items in groupby(items, key=lambda p: p[1]):
+    if _section == "greens":
+        collect_shop_items(shopper, section_items)
+        return
+    elif _section == "frozen items":
+        collect_shop_items(shopper, section_items)
+        collect_shop_items(shopper, section_items)

 # Should trigger, since only one branch has a return statement.
-def foo():
-    from itertools import groupby
-    for _section, section_items in groupby(items, key=lambda p: p[1]):
-        if _section == "greens":
-            collect_shop_items(shopper, section_items)
-            return
-        elif _section == "frozen items":
-            collect_shop_items(shopper, section_items)
-        collect_shop_items(shopper, section_items)  # B031
+for _section, section_items in groupby(items, key=lambda p: p[1]):
+    if _section == "greens":
+        collect_shop_items(shopper, section_items)
+        return
+    elif _section == "frozen items":
+        collect_shop_items(shopper, section_items)
+    collect_shop_items(shopper, section_items)  # B031

 # Let's redefine the `groupby` function to make sure we pick up the correct one.
 # NOTE: This should always be at the end of the file.
--- a/crates/ruff_linter/resources/test/fixtures/flake8_django/DJ008.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_django/DJ008.py
@@ -181,51 +181,3 @@ class SubclassTestModel2(TestModel4):
 # Subclass without __str__
 class SubclassTestModel3(TestModel1):
    pass
-
-
-# Test cases for type-annotated abstract models - these should NOT trigger DJ008
-from typing import ClassVar
-from django_stubs_ext.db.models import TypedModelMeta
-
-
-class TypeAnnotatedAbstractModel1(models.Model):
-    """Model with type-annotated abstract = True - should not trigger DJ008"""
-    new_field = models.CharField(max_length=10)
-
-    class Meta(TypedModelMeta):
-        abstract: ClassVar[bool] = True
-
-
-class TypeAnnotatedAbstractModel2(models.Model):
-    """Model with type-annotated abstract = True using regular Meta - should not trigger DJ008"""  
-    new_field = models.CharField(max_length=10)
-
-    class Meta:
-        abstract: ClassVar[bool] = True
-
-
-class TypeAnnotatedAbstractModel3(models.Model):
-    """Model with type-annotated abstract = True but without ClassVar - should not trigger DJ008"""
-    new_field = models.CharField(max_length=10)
-
-    class Meta:
-        abstract: bool = True
-
-
-class TypeAnnotatedNonAbstractModel(models.Model):
-    """Model with type-annotated abstract = False - should trigger DJ008"""
-    new_field = models.CharField(max_length=10)
-
-    class Meta:
-        abstract: ClassVar[bool] = False
-
-
-class TypeAnnotatedAbstractModelWithStr(models.Model):
-    """Model with type-annotated abstract = True and __str__ method - should not trigger DJ008"""
-    new_field = models.CharField(max_length=10)
-
-    class Meta(TypedModelMeta):
-        abstract: ClassVar[bool] = True
-
-    def __str__(self):
-        return self.new_field
--- a/crates/ruff_linter/resources/test/fixtures/flake8_pie/PIE804.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_pie/PIE804.py
@@ -26,9 +26,8 @@ abc(**{'a': b}, **{'a': c})  # PIE804
 abc(a=1, **{'a': c}, **{'b': c})  # PIE804

 # Some values need to be parenthesized.
-def foo():
-    abc(foo=1, **{'bar': (bar := 1)})  # PIE804
-    abc(foo=1, **{'bar': (yield 1)})  # PIE804
+abc(foo=1, **{'bar': (bar := 1)})  # PIE804
+abc(foo=1, **{'bar': (yield 1)})  # PIE804

 # https://github.com/astral-sh/ruff/issues/18036
 # The autofix for this is unsafe due to the comments inside the dictionary.
--- a/crates/ruff_linter/resources/test/fixtures/flake8_return/RET504.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_return/RET504.py
@@ -422,35 +422,6 @@ def func(a: dict[str, int]) -> list[dict[str, int]]:
        services = a["services"]
        return services

-
-# See: https://github.com/astral-sh/ruff/issues/14052
-def outer() -> list[object]:
-    @register
-    async def inner() -> None:
-        print(layout)
-
-    layout = [...]
-    return layout
-
-def outer() -> list[object]:
-    with open("") as f:
-        async def inner() -> None:
-            print(layout)
-
-    layout = [...]
-    return layout
-
-
-def outer() -> list[object]:
-    def inner():
-        with open("") as f:
-            async def inner_inner() -> None:
-                print(layout)
-
-    layout = [...]
-    return layout
-
-
 # See: https://github.com/astral-sh/ruff/issues/18411
 def f():
    (#=
--- a/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM115.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM115.py
@@ -27,9 +27,8 @@ with contextlib.ExitStack() as stack:
    close_files = stack.pop_all().close

 # OK
-async def foo():
-    with contextlib.AsyncExitStack() as exit_stack:
-        f = await exit_stack.enter_async_context(open("filename"))
+with contextlib.AsyncExitStack() as exit_stack:
+    f = await exit_stack.enter_async_context(open("filename"))

 # OK (false negative)
 with contextlib.ExitStack():
@@ -276,10 +275,9 @@ class ExampleClassTests(TestCase):
        cls.enterClassContext(open("filename"))

 # OK
-async def foo():
-    class ExampleAsyncTests(IsolatedAsyncioTestCase):
-        async def test_something(self):
-            await self.enterAsyncContext(open("filename"))
+class ExampleAsyncTests(IsolatedAsyncioTestCase):
+    async def test_something(self):
+        await self.enterAsyncContext(open("filename"))

 # OK
 class ExampleTests(TestCase):
--- a/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM116.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_simplify/SIM116.py
@@ -1,99 +1,98 @@
-def foo():
-    # Errors
-    a = "hello"
+# Errors
+a = "hello"

-    # SIM116
-    if a == "foo":
-        return "bar"
-    elif a == "bar":
-        return "baz"
-    elif a == "boo":
-        return "ooh"
+# SIM116
+if a == "foo":
+    return "bar"
+elif a == "bar":
+    return "baz"
+elif a == "boo":
+    return "ooh"
+else:
+    return 42
+
+# SIM116
+if a == 1:
+    return (1, 2, 3)
+elif a == 2:
+    return (4, 5, 6)
+elif a == 3:
+    return (7, 8, 9)
+else:
+    return (10, 11, 12)
+
+# SIM116
+if a == 1:
+    return (1, 2, 3)
+elif a == 2:
+    return (4, 5, 6)
+elif a == 3:
+    return (7, 8, 9)
+
+# SIM116
+if a == "hello 'sir'":
+    return (1, 2, 3)
+elif a == 'goodbye "mam"':
+    return (4, 5, 6)
+elif a == """Fairwell 'mister'""":
+    return (7, 8, 9)
+else:
+    return (10, 11, 12)
+
+# SIM116
+if a == b"one":
+    return 1
+elif a == b"two":
+    return 2
+elif a == b"three":
+    return 3
+
+# SIM116
+if a == "hello 'sir'":
+    return ("hello'", 'hi"', 3)
+elif a == 'goodbye "mam"':
+    return (4, 5, 6)
+elif a == """Fairwell 'mister'""":
+    return (7, 8, 9)
+else:
+    return (10, 11, 12)
+
+# OK
+if a == "foo":
+    return "bar"
+elif a == "bar":
+    return baz()
+elif a == "boo":
+    return "ooh"
+else:
+    return 42
+
+# OK
+if a == b"one":
+    return 1
+elif b == b"two":
+    return 2
+elif a == b"three":
+    return 3
+
+# SIM116
+if func_name == "create":
+    return "A"
+elif func_name == "modify":
+    return "M"
+elif func_name == "remove":
+    return "D"
+elif func_name == "move":
+    return "MV"
+
+# OK
+def no_return_in_else(platform):
+    if platform == "linux":
+        return "auditwheel repair -w {dest_dir} {wheel}"
+    elif platform == "macos":
+        return "delocate-wheel --require-archs {delocate_archs} -w {dest_dir} -v {wheel}"
+    elif platform == "windows":
+        return ""
    else:
-        return 42
-
-    # SIM116
-    if a == 1:
-        return (1, 2, 3)
-    elif a == 2:
-        return (4, 5, 6)
-    elif a == 3:
-        return (7, 8, 9)
-    else:
-        return (10, 11, 12)
-
-    # SIM116
-    if a == 1:
-        return (1, 2, 3)
-    elif a == 2:
-        return (4, 5, 6)
-    elif a == 3:
-        return (7, 8, 9)
-
-    # SIM116
-    if a == "hello 'sir'":
-        return (1, 2, 3)
-    elif a == 'goodbye "mam"':
-        return (4, 5, 6)
-    elif a == """Fairwell 'mister'""":
-        return (7, 8, 9)
-    else:
-        return (10, 11, 12)
-
-    # SIM116
-    if a == b"one":
-        return 1
-    elif a == b"two":
-        return 2
-    elif a == b"three":
-        return 3
-
-    # SIM116
-    if a == "hello 'sir'":
-        return ("hello'", 'hi"', 3)
-    elif a == 'goodbye "mam"':
-        return (4, 5, 6)
-    elif a == """Fairwell 'mister'""":
-        return (7, 8, 9)
-    else:
-        return (10, 11, 12)
-
-    # OK
-    if a == "foo":
-        return "bar"
-    elif a == "bar":
-        return baz()
-    elif a == "boo":
-        return "ooh"
-    else:
-        return 42
-
-    # OK
-    if a == b"one":
-        return 1
-    elif b == b"two":
-        return 2
-    elif a == b"three":
-        return 3
-
-    # SIM116
-    if func_name == "create":
-        return "A"
-    elif func_name == "modify":
-        return "M"
-    elif func_name == "remove":
-        return "D"
-    elif func_name == "move":
-        return "MV"
-
-    # OK
-    def no_return_in_else(platform):
-        if platform == "linux":
-            return "auditwheel repair -w {dest_dir} {wheel}"
-        elif platform == "macos":
-            return "delocate-wheel --require-archs {delocate_archs} -w {dest_dir} -v {wheel}"
-        elif platform == "windows":
-            return ""
-        else:
-            msg = f"Unknown platform: {platform!r}"
-            raise ValueError(msg)
+        msg = f"Unknown platform: {platform!r}"
+        raise ValueError(msg)
--- a/crates/ruff_linter/resources/test/fixtures/flake8_type_checking/TC008.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_type_checking/TC008.py
@@ -50,23 +50,3 @@ class Baz:
    class Nested:
        a: TypeAlias = 'Baz'  # OK
        type A = 'Baz'  # TC008
-
-# O should have parenthesis added
-o: TypeAlias = """int
-| None"""
-type O = """int
-| None"""
-
-# P, Q, and R should not have parenthesis added
-p: TypeAlias = ("""int
-| None""")
-type P = ("""int
-| None""")
-
-q: TypeAlias = """(int
-| None)"""
-type Q = """(int
-| None)"""
-
-r: TypeAlias = """int | None"""
-type R = """int | None"""
--- a/crates/ruff_linter/resources/test/fixtures/flake8_type_checking/whitespace.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_type_checking/whitespace.py
@@ -1,6 +0,0 @@
-# Regression test for: https://github.com/astral-sh/ruff/issues/19175
-# there is a (potentially invisible) unicode formfeed character (000C) between `TYPE_CHECKING` and the backslash
-from typing import TYPE_CHECKING\
-
-if TYPE_CHECKING: import builtins
-builtins.print("!")
--- a/crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/PTH203.py
+++ b/crates/ruff_linter/resources/test/fixtures/flake8_use_pathlib/PTH203.py
@@ -1,4 +1,4 @@
-import os.path, pathlib
+import os.path
 from pathlib import Path
 from os.path import getatime

@@ -10,26 +10,3 @@ os.path.getatime(Path("filename"))
 getatime("filename")
 getatime(b"filename")
 getatime(Path("filename"))
-
-
-file = __file__
-
-os.path.getatime(file)
-os.path.getatime(filename="filename")
-os.path.getatime(filename=Path("filename"))
-
-os.path.getatime(  # comment 1
-    # comment 2
-    "filename"  # comment 3
-    # comment 4
-    ,  # comment 5
-    # comment 6
-)  # comment 7
-
-os.path.getatime("file" + "name")
-
-getatime(Path("filename").resolve())
-
-os.path.getatime(pathlib.Path("filename"))
-
-getatime(Path("dir") / "file.txt")
--- a/crates/ruff_linter/resources/test/fixtures/isort/required_imports/multiple_strings.py
+++ b/crates/ruff_linter/resources/test/fixtures/isort/required_imports/multiple_strings.py
@@ -1,5 +0,0 @@
-"""This is a docstring."""
-"This is not a docstring."
-"This is also not a docstring."
-
-x = 1 
--- a/crates/ruff_linter/resources/test/fixtures/pycodestyle/E27.py
+++ b/crates/ruff_linter/resources/test/fixtures/pycodestyle/E27.py
@@ -81,5 +81,4 @@ match(foo):
 # https://github.com/astral-sh/ruff/issues/12094
 pass;

-def foo():
-    yield, x
+yield, x
--- a/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP008.py
+++ b/crates/ruff_linter/resources/test/fixtures/pyupgrade/UP008.py
@@ -125,19 +125,3 @@ class ClassForCommentEnthusiasts(BaseClass):
            self
            # also a comment
        ).f()
-
-
-# Issue #19096: super calls with keyword arguments should emit diagnostic but not be fixed
-class Ord(int):
-    def __len__(self):
-        return super(Ord, self, uhoh=True, **{"error": True}).bit_length()
-
-class ExampleWithKeywords:
-    def method1(self):
-        super(ExampleWithKeywords, self, invalid=True).some_method()  # Should emit diagnostic but NOT be fixed
-    
-    def method2(self):
-        super(ExampleWithKeywords, self, **{"kwarg": "value"}).some_method()  # Should emit diagnostic but NOT be fixed
-    
-    def method3(self):
-        super(ExampleWithKeywords, self).some_method()  # Should be fixed - no keywords
--- a/crates/ruff_linter/resources/test/fixtures/ruff/RUF009_attrs.py
+++ b/crates/ruff_linter/resources/test/fixtures/ruff/RUF009_attrs.py
@@ -125,20 +125,3 @@ class J:
 class K:
    f: F = F()
    g: G = G()
-
-
-# Regression test for https://github.com/astral-sh/ruff/issues/19014
-# These are all valid field calls and should not cause diagnostics.
-@attr.define
-class TestAttrField:
-    attr_field_factory: list[int] = attr.field(factory=list)
-    attr_field_default: list[int] = attr.field(default=attr.Factory(list))
-    attr_factory: list[int] = attr.Factory(list)
-    attr_ib: list[int] = attr.ib(factory=list)
-    attr_attr: list[int] = attr.attr(factory=list)
-    attr_attrib: list[int] = attr.attrib(factory=list)
-
-
-@attr.attributes
-class TestAttrAttributes:
-    x: list[int] = list()  # RUF009
--- a/crates/ruff_linter/src/checkers/ast/analyze/bindings.rs
+++ b/crates/ruff_linter/src/checkers/ast/analyze/bindings.rs
@@ -4,8 +4,8 @@ use crate::Fix;
 use crate::checkers::ast::Checker;
 use crate::codes::Rule;
 use crate::rules::{
-    flake8_import_conventions, flake8_pyi, flake8_pytest_style, flake8_return,
-    flake8_type_checking, pyflakes, pylint, pyupgrade, refurb, ruff,
+    flake8_import_conventions, flake8_pyi, flake8_pytest_style, flake8_type_checking, pyflakes,
+    pylint, pyupgrade, refurb, ruff,
 };

 /// Run lint rules over the [`Binding`]s.
@@ -25,20 +25,11 @@ pub(crate) fn bindings(checker: &Checker) {
        Rule::ForLoopWrites,
        Rule::CustomTypeVarForSelf,
        Rule::PrivateTypeParameter,
-        Rule::UnnecessaryAssign,
    ]) {
        return;
    }

    for (binding_id, binding) in checker.semantic.bindings.iter_enumerated() {
-        if checker.is_rule_enabled(Rule::UnnecessaryAssign) {
-            if binding.kind.is_function_definition() {
-                flake8_return::rules::unnecessary_assign(
-                    checker,
-                    binding.statement(checker.semantic()).unwrap(),
-                );
-            }
-        }
        if checker.is_rule_enabled(Rule::UnusedVariable) {
            if binding.kind.is_bound_exception()
                && binding.is_unused()
--- a/crates/ruff_linter/src/checkers/ast/analyze/expression.rs
+++ b/crates/ruff_linter/src/checkers/ast/analyze/expression.rs
@@ -7,9 +7,7 @@ use ruff_python_semantic::analyze::typing;
 use ruff_text_size::Ranged;

 use crate::checkers::ast::Checker;
-use crate::preview::{
-    is_assert_raises_exception_call_enabled, is_optional_as_none_in_union_enabled,
-};
+use crate::preview::is_optional_as_none_in_union_enabled;
 use crate::registry::Rule;
 use crate::rules::{
    airflow, flake8_2020, flake8_async, flake8_bandit, flake8_boolean_trap, flake8_bugbear,
@@ -1039,84 +1037,46 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
                flake8_simplify::rules::zip_dict_keys_and_values(checker, call);
            }
            if checker.any_rule_enabled(&[
+                Rule::OsPathAbspath,
                Rule::OsChmod,
                Rule::OsMkdir,
                Rule::OsMakedirs,
                Rule::OsRename,
                Rule::OsReplace,
+                Rule::OsRmdir,
+                Rule::OsRemove,
+                Rule::OsUnlink,
                Rule::OsGetcwd,
+                Rule::OsPathExists,
+                Rule::OsPathExpanduser,
+                Rule::OsPathIsdir,
+                Rule::OsPathIsfile,
+                Rule::OsPathIslink,
+                Rule::OsReadlink,
                Rule::OsStat,
+                Rule::OsPathIsabs,
                Rule::OsPathJoin,
+                Rule::OsPathBasename,
+                Rule::OsPathDirname,
                Rule::OsPathSamefile,
                Rule::OsPathSplitext,
                Rule::BuiltinOpen,
                Rule::PyPath,
+                Rule::OsPathGetatime,
+                Rule::OsPathGetmtime,
+                Rule::OsPathGetctime,
                Rule::Glob,
                Rule::OsListdir,
                Rule::OsSymlink,
            ]) {
                flake8_use_pathlib::rules::replaceable_by_pathlib(checker, call);
            }
-            if let Some(qualified_name) = checker.semantic().resolve_qualified_name(&call.func) {
-                let segments = qualified_name.segments();
-                if checker.is_rule_enabled(Rule::OsPathGetsize) {
-                    flake8_use_pathlib::rules::os_path_getsize(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathGetatime) {
-                    flake8_use_pathlib::rules::os_path_getatime(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathGetctime) {
-                    flake8_use_pathlib::rules::os_path_getctime(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathGetmtime) {
-                    flake8_use_pathlib::rules::os_path_getmtime(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathAbspath) {
-                    flake8_use_pathlib::rules::os_path_abspath(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsRmdir) {
-                    flake8_use_pathlib::rules::os_rmdir(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsRemove) {
-                    flake8_use_pathlib::rules::os_remove(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsUnlink) {
-                    flake8_use_pathlib::rules::os_unlink(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathExists) {
-                    flake8_use_pathlib::rules::os_path_exists(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathExpanduser) {
-                    flake8_use_pathlib::rules::os_path_expanduser(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathBasename) {
-                    flake8_use_pathlib::rules::os_path_basename(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathDirname) {
-                    flake8_use_pathlib::rules::os_path_dirname(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathIsabs) {
-                    flake8_use_pathlib::rules::os_path_isabs(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathIsdir) {
-                    flake8_use_pathlib::rules::os_path_isdir(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathIsfile) {
-                    flake8_use_pathlib::rules::os_path_isfile(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsPathIslink) {
-                    flake8_use_pathlib::rules::os_path_islink(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::OsReadlink) {
-                    flake8_use_pathlib::rules::os_readlink(checker, call, segments);
-                }
-                if checker.is_rule_enabled(Rule::PathConstructorCurrentDirectory) {
-                    flake8_use_pathlib::rules::path_constructor_current_directory(
-                        checker, call, segments,
-                    );
-                }
+            if checker.is_rule_enabled(Rule::OsPathGetsize) {
+                flake8_use_pathlib::rules::os_path_getsize(checker, call);
+            }
+            if checker.is_rule_enabled(Rule::PathConstructorCurrentDirectory) {
+                flake8_use_pathlib::rules::path_constructor_current_directory(checker, call);
            }
-
            if checker.is_rule_enabled(Rule::OsSepSplit) {
                flake8_use_pathlib::rules::os_sep_split(checker, call);
            }
@@ -1270,11 +1230,6 @@ pub(crate) fn expression(expr: &Expr, checker: &Checker) {
            if checker.is_rule_enabled(Rule::NonOctalPermissions) {
                ruff::rules::non_octal_permissions(checker, call);
            }
-            if checker.is_rule_enabled(Rule::AssertRaisesException)
-                && is_assert_raises_exception_call_enabled(checker.settings())
-            {
-                flake8_bugbear::rules::assert_raises_exception_call(checker, call);
-            }
        }
        Expr::Dict(dict) => {
            if checker.any_rule_enabled(&[
--- a/crates/ruff_linter/src/checkers/ast/analyze/statement.rs
+++ b/crates/ruff_linter/src/checkers/ast/analyze/statement.rs
@@ -207,6 +207,7 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
                Rule::UnnecessaryReturnNone,
                Rule::ImplicitReturnValue,
                Rule::ImplicitReturn,
+                Rule::UnnecessaryAssign,
                Rule::SuperfluousElseReturn,
                Rule::SuperfluousElseRaise,
                Rule::SuperfluousElseContinue,
--- a/crates/ruff_linter/src/checkers/ast/mod.rs
+++ b/crates/ruff_linter/src/checkers/ast/mod.rs
@@ -28,7 +28,6 @@ use itertools::Itertools;
 use log::debug;
 use rustc_hash::{FxHashMap, FxHashSet};

-use ruff_db::diagnostic::Diagnostic;
 use ruff_diagnostics::{Applicability, Fix, IsolationLevel};
 use ruff_notebook::{CellOffsets, NotebookIndex};
 use ruff_python_ast::helpers::{collect_import_from_member, is_docstring_stmt, to_module_path};
@@ -75,7 +74,7 @@ use crate::rules::pylint::rules::{AwaitOutsideAsync, LoadBeforeGlobalDeclaration
 use crate::rules::{flake8_pyi, flake8_type_checking, pyflakes, pyupgrade};
 use crate::settings::rule_table::RuleTable;
 use crate::settings::{LinterSettings, TargetVersion, flags};
-use crate::{Edit, Violation};
+use crate::{Edit, OldDiagnostic, Violation};
 use crate::{Locator, docstrings, noqa};

 mod analyze;
@@ -389,7 +388,7 @@ impl<'a> Checker<'a> {

    /// Return a [`DiagnosticGuard`] for reporting a diagnostic.
    ///
-    /// The guard derefs to a [`Diagnostic`], so it can be used to further modify the diagnostic
+    /// The guard derefs to an [`OldDiagnostic`], so it can be used to further modify the diagnostic
    /// before it is added to the collection in the checker on `Drop`.
    pub(crate) fn report_diagnostic<'chk, T: Violation>(
        &'chk self,
@@ -402,7 +401,7 @@ impl<'a> Checker<'a> {
    /// Return a [`DiagnosticGuard`] for reporting a diagnostic if the corresponding rule is
    /// enabled.
    ///
-    /// The guard derefs to a [`Diagnostic`], so it can be used to further modify the diagnostic
+    /// The guard derefs to an [`OldDiagnostic`], so it can be used to further modify the diagnostic
    /// before it is added to the collection in the checker on `Drop`.
    pub(crate) fn report_diagnostic_if_enabled<'chk, T: Violation>(
        &'chk self,
@@ -670,11 +669,7 @@ impl SemanticSyntaxContext for Checker<'_> {
            | SemanticSyntaxErrorKind::InvalidStarExpression
            | SemanticSyntaxErrorKind::AsyncComprehensionInSyncComprehension(_)
            | SemanticSyntaxErrorKind::DuplicateParameter(_)
-            | SemanticSyntaxErrorKind::NonlocalDeclarationAtModuleLevel
-            | SemanticSyntaxErrorKind::LoadBeforeNonlocalDeclaration { .. }
-            | SemanticSyntaxErrorKind::NonlocalAndGlobal(_)
-            | SemanticSyntaxErrorKind::AnnotatedGlobal(_)
-            | SemanticSyntaxErrorKind::AnnotatedNonlocal(_) => {
+            | SemanticSyntaxErrorKind::NonlocalDeclarationAtModuleLevel => {
                self.semantic_errors.borrow_mut().push(error);
            }
        }
@@ -3121,9 +3116,9 @@ pub(crate) fn check_ast(
 /// A type for collecting diagnostics in a given file.
 ///
 /// [`LintContext::report_diagnostic`] can be used to obtain a [`DiagnosticGuard`], which will push
-/// a [`Violation`] to the contained [`Diagnostic`] collection on `Drop`.
+/// a [`Violation`] to the contained [`OldDiagnostic`] collection on `Drop`.
 pub(crate) struct LintContext<'a> {
-    diagnostics: RefCell<Vec<Diagnostic>>,
+    diagnostics: RefCell<Vec<OldDiagnostic>>,
    source_file: SourceFile,
    rules: RuleTable,
    settings: &'a LinterSettings,
@@ -3131,7 +3126,7 @@ pub(crate) struct LintContext<'a> {

 impl<'a> LintContext<'a> {
    /// Create a new collector with the given `source_file` and an empty collection of
-    /// `Diagnostic`s.
+    /// `OldDiagnostic`s.
    pub(crate) fn new(path: &Path, contents: &str, settings: &'a LinterSettings) -> Self {
        let source_file =
            SourceFileBuilder::new(path.to_string_lossy().as_ref(), contents).finish();
@@ -3152,7 +3147,7 @@ impl<'a> LintContext<'a> {

    /// Return a [`DiagnosticGuard`] for reporting a diagnostic.
    ///
-    /// The guard derefs to a [`Diagnostic`], so it can be used to further modify the diagnostic
+    /// The guard derefs to an [`OldDiagnostic`], so it can be used to further modify the diagnostic
    /// before it is added to the collection in the context on `Drop`.
    pub(crate) fn report_diagnostic<'chk, T: Violation>(
        &'chk self,
@@ -3161,7 +3156,7 @@ impl<'a> LintContext<'a> {
    ) -> DiagnosticGuard<'chk, 'a> {
        DiagnosticGuard {
            context: self,
-            diagnostic: Some(kind.into_diagnostic(range, &self.source_file)),
+            diagnostic: Some(OldDiagnostic::new(kind, range, &self.source_file)),
            rule: T::rule(),
        }
    }
@@ -3169,7 +3164,7 @@ impl<'a> LintContext<'a> {
    /// Return a [`DiagnosticGuard`] for reporting a diagnostic if the corresponding rule is
    /// enabled.
    ///
-    /// The guard derefs to a [`Diagnostic`], so it can be used to further modify the diagnostic
+    /// The guard derefs to an [`OldDiagnostic`], so it can be used to further modify the diagnostic
    /// before it is added to the collection in the context on `Drop`.
    pub(crate) fn report_diagnostic_if_enabled<'chk, T: Violation>(
        &'chk self,
@@ -3180,7 +3175,7 @@ impl<'a> LintContext<'a> {
        if self.is_rule_enabled(rule) {
            Some(DiagnosticGuard {
                context: self,
-                diagnostic: Some(kind.into_diagnostic(range, &self.source_file)),
+                diagnostic: Some(OldDiagnostic::new(kind, range, &self.source_file)),
                rule,
            })
        } else {
@@ -3204,17 +3199,17 @@ impl<'a> LintContext<'a> {
    }

    #[inline]
-    pub(crate) fn into_parts(self) -> (Vec<Diagnostic>, SourceFile) {
+    pub(crate) fn into_parts(self) -> (Vec<OldDiagnostic>, SourceFile) {
        (self.diagnostics.into_inner(), self.source_file)
    }

    #[inline]
-    pub(crate) fn as_mut_vec(&mut self) -> &mut Vec<Diagnostic> {
+    pub(crate) fn as_mut_vec(&mut self) -> &mut Vec<OldDiagnostic> {
        self.diagnostics.get_mut()
    }

    #[inline]
-    pub(crate) fn iter(&mut self) -> impl Iterator<Item = &Diagnostic> {
+    pub(crate) fn iter(&mut self) -> impl Iterator<Item = &OldDiagnostic> {
        self.diagnostics.get_mut().iter()
    }
 }
@@ -3232,7 +3227,7 @@ pub(crate) struct DiagnosticGuard<'a, 'b> {
    /// The diagnostic that we want to report.
    ///
    /// This is always `Some` until the `Drop` (or `defuse`) call.
-    diagnostic: Option<Diagnostic>,
+    diagnostic: Option<OldDiagnostic>,
    rule: Rule,
 }

@@ -3258,14 +3253,11 @@ impl DiagnosticGuard<'_, '_> {
    #[inline]
    pub(crate) fn set_fix(&mut self, fix: Fix) {
        if !self.context.rules.should_fix(self.rule) {
-            self.diagnostic.as_mut().unwrap().remove_fix();
+            self.fix = None;
            return;
        }
        let applicability = self.resolve_applicability(&fix);
-        self.diagnostic
-            .as_mut()
-            .unwrap()
-            .set_fix(fix.with_applicability(applicability));
+        self.fix = Some(fix.with_applicability(applicability));
    }

    /// Set the [`Fix`] used to fix the diagnostic, if the provided function returns `Ok`.
@@ -3294,9 +3286,9 @@ impl DiagnosticGuard<'_, '_> {
 }

 impl std::ops::Deref for DiagnosticGuard<'_, '_> {
-    type Target = Diagnostic;
+    type Target = OldDiagnostic;

-    fn deref(&self) -> &Diagnostic {
+    fn deref(&self) -> &OldDiagnostic {
        // OK because `self.diagnostic` is only `None` within `Drop`.
        self.diagnostic.as_ref().unwrap()
    }
@@ -3304,7 +3296,7 @@ impl std::ops::Deref for DiagnosticGuard<'_, '_> {

 /// Return a mutable borrow of the diagnostic in this guard.
 impl std::ops::DerefMut for DiagnosticGuard<'_, '_> {
-    fn deref_mut(&mut self) -> &mut Diagnostic {
+    fn deref_mut(&mut self) -> &mut OldDiagnostic {
        // OK because `self.diagnostic` is only `None` within `Drop`.
        self.diagnostic.as_mut().unwrap()
    }
--- a/crates/ruff_linter/src/checkers/noqa.rs
+++ b/crates/ruff_linter/src/checkers/noqa.rs
@@ -66,9 +66,9 @@ pub(crate) fn check_noqa(
        }

        let noqa_offsets = diagnostic
-            .parent()
+            .parent
            .into_iter()
-            .chain(std::iter::once(diagnostic.expect_range().start()))
+            .chain(std::iter::once(diagnostic.start()))
            .map(|position| noqa_line_for.resolve(position))
            .unique();

--- a/crates/ruff_linter/src/codes.rs
+++ b/crates/ruff_linter/src/codes.rs
@@ -4,7 +4,6 @@
 /// `--select`. For pylint this is e.g. C0414 and E0118 but also C and E01.
 use std::fmt::Formatter;

-use ruff_db::diagnostic::SecondaryCode;
 use strum_macros::EnumIter;

 use crate::registry::Linter;
@@ -53,18 +52,6 @@ impl PartialEq<NoqaCode> for &str {
    }
 }

-impl PartialEq<NoqaCode> for SecondaryCode {
-    fn eq(&self, other: &NoqaCode) -> bool {
-        &self.as_str() == other
-    }
-}
-
-impl PartialEq<SecondaryCode> for NoqaCode {
-    fn eq(&self, other: &SecondaryCode) -> bool {
-        other.eq(self)
-    }
-}
-
 impl serde::Serialize for NoqaCode {
    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
    where
@@ -919,27 +906,27 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
        (Tryceratops, "401") => (RuleGroup::Stable, rules::tryceratops::rules::VerboseLogMessage),

        // flake8-use-pathlib
-        (Flake8UsePathlib, "100") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathAbspath),
+        (Flake8UsePathlib, "100") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathAbspath),
        (Flake8UsePathlib, "101") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsChmod),
        (Flake8UsePathlib, "102") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsMkdir),
        (Flake8UsePathlib, "103") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsMakedirs),
        (Flake8UsePathlib, "104") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsRename),
        (Flake8UsePathlib, "105") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsReplace),
-        (Flake8UsePathlib, "106") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRmdir),
-        (Flake8UsePathlib, "107") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsRemove),
-        (Flake8UsePathlib, "108") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsUnlink),
+        (Flake8UsePathlib, "106") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsRmdir),
+        (Flake8UsePathlib, "107") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsRemove),
+        (Flake8UsePathlib, "108") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsUnlink),
        (Flake8UsePathlib, "109") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsGetcwd),
-        (Flake8UsePathlib, "110") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathExists),
-        (Flake8UsePathlib, "111") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathExpanduser),
-        (Flake8UsePathlib, "112") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathIsdir),
-        (Flake8UsePathlib, "113") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathIsfile),
-        (Flake8UsePathlib, "114") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathIslink),
-        (Flake8UsePathlib, "115") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsReadlink),
+        (Flake8UsePathlib, "110") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathExists),
+        (Flake8UsePathlib, "111") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathExpanduser),
+        (Flake8UsePathlib, "112") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathIsdir),
+        (Flake8UsePathlib, "113") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathIsfile),
+        (Flake8UsePathlib, "114") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathIslink),
+        (Flake8UsePathlib, "115") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsReadlink),
        (Flake8UsePathlib, "116") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsStat),
-        (Flake8UsePathlib, "117") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathIsabs),
+        (Flake8UsePathlib, "117") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathIsabs),
        (Flake8UsePathlib, "118") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathJoin),
-        (Flake8UsePathlib, "119") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathBasename),
-        (Flake8UsePathlib, "120") => (RuleGroup::Stable, rules::flake8_use_pathlib::rules::OsPathDirname),
+        (Flake8UsePathlib, "119") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathBasename),
+        (Flake8UsePathlib, "120") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathDirname),
        (Flake8UsePathlib, "121") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathSamefile),
        (Flake8UsePathlib, "122") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::OsPathSplitext),
        (Flake8UsePathlib, "123") => (RuleGroup::Stable, rules::flake8_use_pathlib::violations::BuiltinOpen),
--- a/crates/ruff_linter/src/fix/edits.rs
+++ b/crates/ruff_linter/src/fix/edits.rs
@@ -618,7 +618,7 @@ mod tests {
    use crate::fix::edits::{
        add_to_dunder_all, make_redundant_alias, next_stmt_break, trailing_semicolon,
    };
-    use crate::{Edit, Fix, Locator, Violation};
+    use crate::{Edit, Fix, Locator, OldDiagnostic};

    /// Parse the given source using [`Mode::Module`] and return the first statement.
    fn parse_first_stmt(source: &str) -> Result<Stmt> {
@@ -749,12 +749,12 @@ x = 1 \
        let diag = {
            use crate::rules::pycodestyle::rules::MissingNewlineAtEndOfFile;
            let mut iter = edits.into_iter();
-            // The choice of rule here is arbitrary.
-            let mut diagnostic = MissingNewlineAtEndOfFile.into_diagnostic(
+            let mut diagnostic = OldDiagnostic::new(
+                MissingNewlineAtEndOfFile, // The choice of rule here is arbitrary.
                TextRange::default(),
                &SourceFileBuilder::new("<filename>", "<code>").finish(),
            );
-            diagnostic.set_fix(Fix::safe_edits(
+            diagnostic.fix = Some(Fix::safe_edits(
                iter.next().ok_or(anyhow!("expected edits nonempty"))?,
                iter,
            ));
--- a/crates/ruff_linter/src/fix/mod.rs
+++ b/crates/ruff_linter/src/fix/mod.rs
@@ -3,12 +3,12 @@ use std::collections::BTreeSet;
 use itertools::Itertools;
 use rustc_hash::FxHashSet;

-use ruff_db::diagnostic::Diagnostic;
 use ruff_diagnostics::{IsolationLevel, SourceMap};
 use ruff_text_size::{Ranged, TextLen, TextRange, TextSize};

 use crate::Locator;
 use crate::linter::FixTable;
+use crate::message::OldDiagnostic;
 use crate::registry::Rule;
 use crate::settings::types::UnsafeFixes;
 use crate::{Edit, Fix};
@@ -28,7 +28,7 @@ pub(crate) struct FixResult {

 /// Fix errors in a file, and write the fixed source code to disk.
 pub(crate) fn fix_file(
-    diagnostics: &[Diagnostic],
+    diagnostics: &[OldDiagnostic],
    locator: &Locator,
    unsafe_fixes: UnsafeFixes,
 ) -> Option<FixResult> {
@@ -52,7 +52,7 @@ pub(crate) fn fix_file(

 /// Apply a series of fixes.
 fn apply_fixes<'a>(
-    diagnostics: impl Iterator<Item = &'a Diagnostic>,
+    diagnostics: impl Iterator<Item = &'a OldDiagnostic>,
    locator: &'a Locator<'a>,
 ) -> FixResult {
    let mut output = String::with_capacity(locator.len());
@@ -172,25 +172,26 @@ mod tests {
    use ruff_source_file::SourceFileBuilder;
    use ruff_text_size::{Ranged, TextSize};

+    use crate::Locator;
+    use crate::OldDiagnostic;
    use crate::fix::{FixResult, apply_fixes};
    use crate::rules::pycodestyle::rules::MissingNewlineAtEndOfFile;
    use crate::{Edit, Fix};
-    use crate::{Locator, Violation};
-    use ruff_db::diagnostic::Diagnostic;

    fn create_diagnostics(
        filename: &str,
        source: &str,
        edit: impl IntoIterator<Item = Edit>,
-    ) -> Vec<Diagnostic> {
+    ) -> Vec<OldDiagnostic> {
        edit.into_iter()
            .map(|edit| {
                // The choice of rule here is arbitrary.
-                let mut diagnostic = MissingNewlineAtEndOfFile.into_diagnostic(
+                let mut diagnostic = OldDiagnostic::new(
+                    MissingNewlineAtEndOfFile,
                    edit.range(),
                    &SourceFileBuilder::new(filename, source).finish(),
                );
-                diagnostic.set_fix(Fix::safe_edit(edit));
+                diagnostic.fix = Some(Fix::safe_edit(edit));
                diagnostic
            })
            .collect()
--- a/crates/ruff_linter/src/importer/insertion.rs
+++ b/crates/ruff_linter/src/importer/insertion.rs
@@ -5,7 +5,6 @@ use ruff_python_ast::Stmt;
 use ruff_python_ast::helpers::is_docstring_stmt;
 use ruff_python_codegen::Stylist;
 use ruff_python_parser::{TokenKind, Tokens};
-use ruff_python_trivia::is_python_whitespace;
 use ruff_python_trivia::{PythonWhitespace, textwrap::indent};
 use ruff_source_file::{LineRanges, UniversalNewlineIterator};
 use ruff_text_size::{Ranged, TextSize};
@@ -275,12 +274,19 @@ impl<'a> Insertion<'a> {
    }
 }

-/// Find the end of the docstring (first string statement).
+/// Find the end of the last docstring.
 fn match_docstring_end(body: &[Stmt]) -> Option<TextSize> {
-    let stmt = body.first()?;
+    let mut iter = body.iter();
+    let mut stmt = iter.next()?;
    if !is_docstring_stmt(stmt) {
        return None;
    }
+    for next in iter {
+        if !is_docstring_stmt(next) {
+            break;
+        }
+        stmt = next;
+    }
    Some(stmt.end())
 }

@@ -300,7 +306,7 @@ fn match_semicolon(s: &str) -> Option<TextSize> {
 fn match_continuation(s: &str) -> Option<TextSize> {
    for (offset, c) in s.char_indices() {
        match c {
-            _ if is_python_whitespace(c) => continue,
+            ' ' | '\t' => continue,
            '\\' => return Some(TextSize::try_from(offset).unwrap()),
            _ => break,
        }
@@ -360,7 +366,7 @@ mod tests {
        .trim_start();
        assert_eq!(
            insert(contents)?,
-            Insertion::own_line("", TextSize::from(20), "\n")
+            Insertion::own_line("", TextSize::from(40), "\n")
        );

        let contents = r"
--- a/crates/ruff_linter/src/lib.rs
+++ b/crates/ruff_linter/src/lib.rs
@@ -14,6 +14,7 @@ pub use rule_selector::RuleSelector;
 pub use rule_selector::clap_completion::RuleSelectorParser;
 pub use rules::pycodestyle::rules::IOError;

+pub use message::OldDiagnostic;
 pub(crate) use ruff_diagnostics::{Applicability, Edit, Fix};
 pub use violation::{AlwaysFixableViolation, FixAvailability, Violation, ViolationMetadata};

--- a/crates/ruff_linter/src/linter.rs
+++ b/crates/ruff_linter/src/linter.rs
@@ -7,14 +7,15 @@ use itertools::Itertools;
 use ruff_python_parser::semantic_errors::SemanticSyntaxError;
 use rustc_hash::FxBuildHasher;

-use ruff_db::diagnostic::{Diagnostic, SecondaryCode};
 use ruff_notebook::Notebook;
 use ruff_python_ast::{ModModule, PySourceType, PythonVersion};
 use ruff_python_codegen::Stylist;
 use ruff_python_index::Indexer;
 use ruff_python_parser::{ParseError, ParseOptions, Parsed, UnsupportedSyntaxError};
 use ruff_source_file::SourceFile;
+use ruff_text_size::Ranged;

+use crate::OldDiagnostic;
 use crate::checkers::ast::{LintContext, check_ast};
 use crate::checkers::filesystem::check_file_path;
 use crate::checkers::imports::check_imports;
@@ -24,7 +25,7 @@ use crate::checkers::tokens::check_tokens;
 use crate::directives::Directives;
 use crate::doc_lines::{doc_lines_from_ast, doc_lines_from_tokens};
 use crate::fix::{FixResult, fix_file};
-use crate::message::create_syntax_error_diagnostic;
+use crate::message::SecondaryCode;
 use crate::noqa::add_noqa;
 use crate::package::PackageRoot;
 use crate::preview::is_py314_support_enabled;
@@ -40,7 +41,7 @@ pub(crate) mod float;

 pub struct LinterResult {
    /// A collection of diagnostic messages generated by the linter.
-    pub diagnostics: Vec<Diagnostic>,
+    pub diagnostics: Vec<OldDiagnostic>,
    /// Flag indicating that the parsed source code does not contain any
    /// [`ParseError`]s
    has_valid_syntax: bool,
@@ -144,7 +145,7 @@ pub struct FixerResult<'a> {
    pub fixed: FixTable,
 }

-/// Generate [`Diagnostic`]s from the source code contents at the given `Path`.
+/// Generate [`OldDiagnostic`]s from the source code contents at the given `Path`.
 #[expect(clippy::too_many_arguments)]
 pub fn check_path(
    path: &Path,
@@ -159,7 +160,7 @@ pub fn check_path(
    source_type: PySourceType,
    parsed: &Parsed<ModModule>,
    target_version: TargetVersion,
-) -> Vec<Diagnostic> {
+) -> Vec<OldDiagnostic> {
    // Aggregate all diagnostics.
    let mut context = LintContext::new(path, locator.contents(), settings);

@@ -381,7 +382,7 @@ pub fn check_path(
    if !parsed.has_valid_syntax() {
        // Avoid fixing in case the source code contains syntax errors.
        for diagnostic in &mut diagnostics {
-            diagnostic.remove_fix();
+            diagnostic.fix = None;
        }
    }

@@ -392,6 +393,7 @@ pub fn check_path(
        parsed.errors(),
        syntax_errors,
        &semantic_syntax_errors,
+        locator,
        directives,
        &source_file,
    )
@@ -457,7 +459,7 @@ pub fn add_noqa_to_path(
    )
 }

-/// Generate a [`Diagnostic`] for each diagnostic triggered by the given source code.
+/// Generate an [`OldDiagnostic`] for each diagnostic triggered by the given source code.
 pub fn lint_only(
    path: &Path,
    package: Option<PackageRoot<'_>>,
@@ -514,7 +516,7 @@ pub fn lint_only(

    LinterResult {
        has_valid_syntax: parsed.has_valid_syntax(),
-        has_no_syntax_errors: !diagnostics.iter().any(Diagnostic::is_invalid_syntax),
+        has_no_syntax_errors: !diagnostics.iter().any(OldDiagnostic::is_syntax_error),
        diagnostics,
    }
 }
@@ -523,32 +525,30 @@ pub fn lint_only(
 ///
 /// Also use `directives` to attach noqa offsets to lint diagnostics.
 fn diagnostics_to_messages(
-    diagnostics: Vec<Diagnostic>,
+    diagnostics: Vec<OldDiagnostic>,
    parse_errors: &[ParseError],
    unsupported_syntax_errors: &[UnsupportedSyntaxError],
    semantic_syntax_errors: &[SemanticSyntaxError],
+    locator: &Locator,
    directives: &Directives,
    source_file: &SourceFile,
-) -> Vec<Diagnostic> {
+) -> Vec<OldDiagnostic> {
    parse_errors
        .iter()
        .map(|parse_error| {
-            create_syntax_error_diagnostic(source_file.clone(), &parse_error.error, parse_error)
+            OldDiagnostic::from_parse_error(parse_error, locator, source_file.clone())
        })
        .chain(unsupported_syntax_errors.iter().map(|syntax_error| {
-            create_syntax_error_diagnostic(source_file.clone(), syntax_error, syntax_error)
+            OldDiagnostic::from_unsupported_syntax_error(syntax_error, source_file.clone())
        }))
        .chain(
            semantic_syntax_errors
                .iter()
-                .map(|error| create_syntax_error_diagnostic(source_file.clone(), error, error)),
+                .map(|error| OldDiagnostic::from_semantic_syntax_error(error, source_file.clone())),
        )
-        .chain(diagnostics.into_iter().map(|mut diagnostic| {
-            let noqa_offset = directives
-                .noqa_line_for
-                .resolve(diagnostic.expect_range().start());
-            diagnostic.set_noqa_offset(noqa_offset);
-            diagnostic
+        .chain(diagnostics.into_iter().map(|diagnostic| {
+            let noqa_offset = directives.noqa_line_for.resolve(diagnostic.start());
+            diagnostic.with_noqa_offset(noqa_offset)
        }))
        .collect()
 }
@@ -629,7 +629,7 @@ pub fn lint_fix<'a>(

        if iterations == 0 {
            has_valid_syntax = parsed.has_valid_syntax();
-            has_no_syntax_errors = !diagnostics.iter().any(Diagnostic::is_invalid_syntax);
+            has_no_syntax_errors = !diagnostics.iter().any(OldDiagnostic::is_syntax_error);
        } else {
            // If the source code had no syntax errors on the first pass, but
            // does on a subsequent pass, then we've introduced a
@@ -687,8 +687,8 @@ where
 }

 #[expect(clippy::print_stderr)]
-fn report_failed_to_converge_error(path: &Path, transformed: &str, diagnostics: &[Diagnostic]) {
-    let codes = collect_rule_codes(diagnostics.iter().filter_map(Diagnostic::secondary_code));
+fn report_failed_to_converge_error(path: &Path, transformed: &str, diagnostics: &[OldDiagnostic]) {
+    let codes = collect_rule_codes(diagnostics.iter().filter_map(OldDiagnostic::secondary_code));
    if cfg!(debug_assertions) {
        eprintln!(
            "{}{} Failed to converge after {} iterations in `{}` with rule codes {}:---\n{}\n---",
@@ -806,12 +806,13 @@ mod tests {
    use ruff_python_index::Indexer;
    use ruff_python_parser::ParseOptions;
    use ruff_python_trivia::textwrap::dedent;
+    use ruff_text_size::Ranged;
    use test_case::test_case;

-    use ruff_db::diagnostic::Diagnostic;
    use ruff_notebook::{Notebook, NotebookError};

    use crate::linter::check_path;
+    use crate::message::OldDiagnostic;
    use crate::registry::Rule;
    use crate::settings::LinterSettings;
    use crate::source_kind::SourceKind;
@@ -969,7 +970,7 @@ mod tests {

    /// Wrapper around `test_contents_syntax_errors` for testing a snippet of code instead of a
    /// file.
-    fn test_snippet_syntax_errors(contents: &str, settings: &LinterSettings) -> Vec<Diagnostic> {
+    fn test_snippet_syntax_errors(contents: &str, settings: &LinterSettings) -> Vec<OldDiagnostic> {
        let contents = dedent(contents);
        test_contents_syntax_errors(
            &SourceKind::Python(contents.to_string()),
@@ -984,7 +985,7 @@ mod tests {
        source_kind: &SourceKind,
        path: &Path,
        settings: &LinterSettings,
-    ) -> Vec<Diagnostic> {
+    ) -> Vec<OldDiagnostic> {
        let source_type = PySourceType::from(path);
        let target_version = settings.resolve_target_version(path);
        let options =
@@ -1015,7 +1016,7 @@ mod tests {
            &parsed,
            target_version,
        );
-        diagnostics.sort_by_key(|diagnostic| diagnostic.expect_range().start());
+        diagnostics.sort_by_key(Ranged::start);
        diagnostics
    }

--- a/crates/ruff_linter/src/logging.rs
+++ b/crates/ruff_linter/src/logging.rs
@@ -1,4 +1,4 @@
-use std::fmt::{Display, Formatter};
+use std::fmt::{Display, Formatter, Write};
 use std::path::{Path, PathBuf};
 use std::sync::{LazyLock, Mutex};

@@ -6,7 +6,7 @@ use anyhow::Result;
 use colored::Colorize;
 use fern;
 use log::Level;
-use ruff_python_parser::ParseError;
+use ruff_python_parser::{ParseError, ParseErrorType};
 use rustc_hash::FxHashSet;

 use ruff_source_file::{LineColumn, LineIndex, OneIndexed, SourceCode};
@@ -248,7 +248,7 @@ impl Display for DisplayParseError {
                    row = location.line,
                    column = location.column,
                    colon = ":".cyan(),
-                    inner = self.error.error
+                    inner = &DisplayParseErrorType(&self.error.error)
                )
            }
            ErrorLocation::Cell(cell, location) => {
@@ -259,13 +259,27 @@ impl Display for DisplayParseError {
                    row = location.line,
                    column = location.column,
                    colon = ":".cyan(),
-                    inner = self.error.error
+                    inner = &DisplayParseErrorType(&self.error.error)
                )
            }
        }
    }
 }

+pub(crate) struct DisplayParseErrorType<'a>(&'a ParseErrorType);
+
+impl<'a> DisplayParseErrorType<'a> {
+    pub(crate) fn new(error: &'a ParseErrorType) -> Self {
+        Self(error)
+    }
+}
+
+impl Display for DisplayParseErrorType<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", TruncateAtNewline(&self.0))
+    }
+}
+
 #[derive(Debug)]
 enum ErrorLocation {
    /// The error occurred in a Python file.
@@ -274,6 +288,44 @@ enum ErrorLocation {
    Cell(OneIndexed, LineColumn),
 }

+/// Truncates the display text before the first newline character to avoid line breaks.
+struct TruncateAtNewline<'a>(&'a dyn Display);
+
+impl Display for TruncateAtNewline<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        struct TruncateAdapter<'a> {
+            inner: &'a mut dyn Write,
+            after_new_line: bool,
+        }
+
+        impl Write for TruncateAdapter<'_> {
+            fn write_str(&mut self, s: &str) -> std::fmt::Result {
+                if self.after_new_line {
+                    Ok(())
+                } else {
+                    if let Some(end) = s.find(['\n', '\r']) {
+                        self.inner.write_str(&s[..end])?;
+                        self.inner.write_str("\u{23ce}...")?;
+                        self.after_new_line = true;
+                        Ok(())
+                    } else {
+                        self.inner.write_str(s)
+                    }
+                }
+            }
+        }
+
+        write!(
+            TruncateAdapter {
+                inner: f,
+                after_new_line: false,
+            },
+            "{}",
+            self.0
+        )
+    }
+}
+
 #[cfg(test)]
 mod tests {
    use crate::logging::LogLevel;
--- a/crates/ruff_linter/src/message/azure.rs
+++ b/crates/ruff_linter/src/message/azure.rs
@@ -0,0 +1,70 @@
+use std::io::Write;
+
+use ruff_source_file::LineColumn;
+
+use crate::message::{Emitter, EmitterContext, OldDiagnostic};
+
+/// Generate error logging commands for Azure Pipelines format.
+/// See [documentation](https://learn.microsoft.com/en-us/azure/devops/pipelines/scripts/logging-commands?view=azure-devops&tabs=bash#logissue-log-an-error-or-warning)
+#[derive(Default)]
+pub struct AzureEmitter;
+
+impl Emitter for AzureEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        diagnostics: &[OldDiagnostic],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        for diagnostic in diagnostics {
+            let location = if context.is_notebook(&diagnostic.filename()) {
+                // We can't give a reasonable location for the structured formats,
+                // so we show one that's clearly a fallback
+                LineColumn::default()
+            } else {
+                diagnostic.compute_start_location()
+            };
+
+            writeln!(
+                writer,
+                "##vso[task.logissue type=error\
+                        ;sourcepath={filename};linenumber={line};columnnumber={col};{code}]{body}",
+                filename = diagnostic.filename(),
+                line = location.line,
+                col = location.column,
+                code = diagnostic
+                    .secondary_code()
+                    .map_or_else(String::new, |code| format!("code={code};")),
+                body = diagnostic.body(),
+            )?;
+        }
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use insta::assert_snapshot;
+
+    use crate::message::AzureEmitter;
+    use crate::message::tests::{
+        capture_emitter_output, create_diagnostics, create_syntax_error_diagnostics,
+    };
+
+    #[test]
+    fn output() {
+        let mut emitter = AzureEmitter;
+        let content = capture_emitter_output(&mut emitter, &create_diagnostics());
+
+        assert_snapshot!(content);
+    }
+
+    #[test]
+    fn syntax_errors() {
+        let mut emitter = AzureEmitter;
+        let content = capture_emitter_output(&mut emitter, &create_syntax_error_diagnostics());
+
+        assert_snapshot!(content);
+    }
+}
--- a/crates/ruff_linter/src/message/diff.rs
+++ b/crates/ruff_linter/src/message/diff.rs
@@ -2,12 +2,13 @@ use std::fmt::{Display, Formatter};
 use std::num::NonZeroUsize;

 use colored::{Color, ColoredString, Colorize, Styles};
+
+use ruff_text_size::{Ranged, TextRange, TextSize};
 use similar::{ChangeTag, TextDiff};

-use ruff_db::diagnostic::Diagnostic;
 use ruff_source_file::{OneIndexed, SourceFile};
-use ruff_text_size::{Ranged, TextRange, TextSize};

+use crate::message::OldDiagnostic;
 use crate::text_helpers::ShowNonprinting;
 use crate::{Applicability, Fix};

@@ -21,13 +22,13 @@ use crate::{Applicability, Fix};
 /// * Compute the diff from the [`Edit`] because diff calculation is expensive.
 pub(super) struct Diff<'a> {
    fix: &'a Fix,
-    source_code: &'a SourceFile,
+    source_code: SourceFile,
 }

 impl<'a> Diff<'a> {
-    pub(crate) fn from_message(message: &'a Diagnostic) -> Option<Diff<'a>> {
+    pub(crate) fn from_message(message: &'a OldDiagnostic) -> Option<Diff<'a>> {
        message.fix().map(|fix| Diff {
-            source_code: message.expect_ruff_source_file(),
+            source_code: message.source_file(),
            fix,
        })
    }
--- a/crates/ruff_linter/src/message/github.rs
+++ b/crates/ruff_linter/src/message/github.rs
@@ -1,10 +1,9 @@
 use std::io::Write;

-use ruff_db::diagnostic::Diagnostic;
 use ruff_source_file::LineColumn;

 use crate::fs::relativize_path;
-use crate::message::{Emitter, EmitterContext};
+use crate::message::{Emitter, EmitterContext, OldDiagnostic};

 /// Generate error workflow command in GitHub Actions format.
 /// See: [GitHub documentation](https://docs.github.com/en/actions/reference/workflow-commands-for-github-actions#setting-an-error-message)
@@ -15,13 +14,12 @@ impl Emitter for GithubEmitter {
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        context: &EmitterContext,
    ) -> anyhow::Result<()> {
        for diagnostic in diagnostics {
-            let source_location = diagnostic.expect_ruff_start_location();
-            let filename = diagnostic.expect_ruff_filename();
-            let location = if context.is_notebook(&filename) {
+            let source_location = diagnostic.compute_start_location();
+            let location = if context.is_notebook(&diagnostic.filename()) {
                // We can't give a reasonable location for the structured formats,
                // so we show one that's clearly a fallback
                LineColumn::default()
@@ -29,7 +27,7 @@ impl Emitter for GithubEmitter {
                source_location
            };

-            let end_location = diagnostic.expect_ruff_end_location();
+            let end_location = diagnostic.compute_end_location();

            write!(
                writer,
@@ -37,7 +35,7 @@ impl Emitter for GithubEmitter {
                code = diagnostic
                    .secondary_code()
                    .map_or_else(String::new, |code| format!(" ({code})")),
-                file = filename,
+                file = diagnostic.filename(),
                row = source_location.line,
                column = source_location.column,
                end_row = end_location.line,
@@ -47,7 +45,7 @@ impl Emitter for GithubEmitter {
            write!(
                writer,
                "{path}:{row}:{column}:",
-                path = relativize_path(&filename),
+                path = relativize_path(&*diagnostic.filename()),
                row = location.line,
                column = location.column,
            )?;
--- a/crates/ruff_linter/src/message/gitlab.rs
+++ b/crates/ruff_linter/src/message/gitlab.rs
@@ -7,10 +7,8 @@ use serde::ser::SerializeSeq;
 use serde::{Serialize, Serializer};
 use serde_json::json;

-use ruff_db::diagnostic::Diagnostic;
-
 use crate::fs::{relativize_path, relativize_path_to};
-use crate::message::{Emitter, EmitterContext};
+use crate::message::{Emitter, EmitterContext, OldDiagnostic};

 /// Generate JSON with violations in GitLab CI format
 //  https://docs.gitlab.com/ee/ci/testing/code_quality.html#implement-a-custom-tool
@@ -30,7 +28,7 @@ impl Emitter for GitlabEmitter {
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        context: &EmitterContext,
    ) -> anyhow::Result<()> {
        serde_json::to_writer_pretty(
@@ -47,7 +45,7 @@ impl Emitter for GitlabEmitter {
 }

 struct SerializedMessages<'a> {
-    diagnostics: &'a [Diagnostic],
+    diagnostics: &'a [OldDiagnostic],
    context: &'a EmitterContext<'a>,
    project_dir: Option<&'a str>,
 }
@@ -61,11 +59,10 @@ impl Serialize for SerializedMessages<'_> {
        let mut fingerprints = HashSet::<u64>::with_capacity(self.diagnostics.len());

        for diagnostic in self.diagnostics {
-            let start_location = diagnostic.expect_ruff_start_location();
-            let end_location = diagnostic.expect_ruff_end_location();
+            let start_location = diagnostic.compute_start_location();
+            let end_location = diagnostic.compute_end_location();

-            let filename = diagnostic.expect_ruff_filename();
-            let lines = if self.context.is_notebook(&filename) {
+            let lines = if self.context.is_notebook(&diagnostic.filename()) {
                // We can't give a reasonable location for the structured formats,
                // so we show one that's clearly a fallback
                json!({
@@ -80,8 +77,8 @@ impl Serialize for SerializedMessages<'_> {
            };

            let path = self.project_dir.as_ref().map_or_else(
-                || relativize_path(&filename),
-                |project_dir| relativize_path_to(&filename, project_dir),
+                || relativize_path(&*diagnostic.filename()),
+                |project_dir| relativize_path_to(&*diagnostic.filename(), project_dir),
            );

            let mut message_fingerprint = fingerprint(diagnostic, &path, 0);
@@ -123,7 +120,7 @@ impl Serialize for SerializedMessages<'_> {
 }

 /// Generate a unique fingerprint to identify a violation.
-fn fingerprint(message: &Diagnostic, project_path: &str, salt: u64) -> u64 {
+fn fingerprint(message: &OldDiagnostic, project_path: &str, salt: u64) -> u64 {
    let mut hasher = DefaultHasher::new();

    salt.hash(&mut hasher);
--- a/crates/ruff_linter/src/message/grouped.rs
+++ b/crates/ruff_linter/src/message/grouped.rs
@@ -4,14 +4,15 @@ use std::num::NonZeroUsize;

 use colored::Colorize;

-use ruff_db::diagnostic::Diagnostic;
 use ruff_notebook::NotebookIndex;
 use ruff_source_file::OneIndexed;

 use crate::fs::relativize_path;
 use crate::message::diff::calculate_print_width;
 use crate::message::text::{MessageCodeFrame, RuleCodeAndBody};
-use crate::message::{Emitter, EmitterContext, MessageWithLocation, group_diagnostics_by_filename};
+use crate::message::{
+    Emitter, EmitterContext, MessageWithLocation, OldDiagnostic, group_diagnostics_by_filename,
+};
 use crate::settings::types::UnsafeFixes;

 #[derive(Default)]
@@ -45,7 +46,7 @@ impl Emitter for GroupedEmitter {
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        context: &EmitterContext,
    ) -> anyhow::Result<()> {
        for (filename, messages) in group_diagnostics_by_filename(diagnostics) {
@@ -72,7 +73,7 @@ impl Emitter for GroupedEmitter {
                    writer,
                    "{}",
                    DisplayGroupedMessage {
-                        notebook_index: context.notebook_index(&message.expect_ruff_filename()),
+                        notebook_index: context.notebook_index(&message.filename()),
                        message,
                        show_fix_status: self.show_fix_status,
                        unsafe_fixes: self.unsafe_fixes,
--- a/crates/ruff_linter/src/message/json.rs
+++ b/crates/ruff_linter/src/message/json.rs
@@ -0,0 +1,218 @@
+use std::io::Write;
+
+use serde::ser::SerializeSeq;
+use serde::{Serialize, Serializer};
+use serde_json::{Value, json};
+
+use ruff_notebook::NotebookIndex;
+use ruff_source_file::{LineColumn, OneIndexed, SourceCode};
+use ruff_text_size::Ranged;
+
+use crate::Edit;
+use crate::message::{Emitter, EmitterContext, OldDiagnostic};
+
+#[derive(Default)]
+pub struct JsonEmitter;
+
+impl Emitter for JsonEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        diagnostics: &[OldDiagnostic],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        serde_json::to_writer_pretty(
+            writer,
+            &ExpandedMessages {
+                diagnostics,
+                context,
+            },
+        )?;
+
+        Ok(())
+    }
+}
+
+struct ExpandedMessages<'a> {
+    diagnostics: &'a [OldDiagnostic],
+    context: &'a EmitterContext<'a>,
+}
+
+impl Serialize for ExpandedMessages<'_> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_seq(Some(self.diagnostics.len()))?;
+
+        for message in self.diagnostics {
+            let value = message_to_json_value(message, self.context);
+            s.serialize_element(&value)?;
+        }
+
+        s.end()
+    }
+}
+
+pub(crate) fn message_to_json_value(message: &OldDiagnostic, context: &EmitterContext) -> Value {
+    let source_file = message.source_file();
+    let source_code = source_file.to_source_code();
+    let notebook_index = context.notebook_index(&message.filename());
+
+    let fix = message.fix().map(|fix| {
+        json!({
+            "applicability": fix.applicability(),
+            "message": message.suggestion(),
+            "edits": &ExpandedEdits { edits: fix.edits(), source_code: &source_code, notebook_index },
+        })
+    });
+
+    let mut start_location = source_code.line_column(message.start());
+    let mut end_location = source_code.line_column(message.end());
+    let mut noqa_location = message
+        .noqa_offset()
+        .map(|offset| source_code.line_column(offset));
+    let mut notebook_cell_index = None;
+
+    if let Some(notebook_index) = notebook_index {
+        notebook_cell_index = Some(
+            notebook_index
+                .cell(start_location.line)
+                .unwrap_or(OneIndexed::MIN),
+        );
+        start_location = notebook_index.translate_line_column(&start_location);
+        end_location = notebook_index.translate_line_column(&end_location);
+        noqa_location =
+            noqa_location.map(|location| notebook_index.translate_line_column(&location));
+    }
+
+    json!({
+        "code": message.secondary_code(),
+        "url": message.to_url(),
+        "message": message.body(),
+        "fix": fix,
+        "cell": notebook_cell_index,
+        "location": location_to_json(start_location),
+        "end_location": location_to_json(end_location),
+        "filename": message.filename(),
+        "noqa_row": noqa_location.map(|location| location.line)
+    })
+}
+
+fn location_to_json(location: LineColumn) -> serde_json::Value {
+    json!({
+        "row": location.line,
+        "column": location.column
+    })
+}
+
+struct ExpandedEdits<'a> {
+    edits: &'a [Edit],
+    source_code: &'a SourceCode<'a, 'a>,
+    notebook_index: Option<&'a NotebookIndex>,
+}
+
+impl Serialize for ExpandedEdits<'_> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut s = serializer.serialize_seq(Some(self.edits.len()))?;
+
+        for edit in self.edits {
+            let mut location = self.source_code.line_column(edit.start());
+            let mut end_location = self.source_code.line_column(edit.end());
+
+            if let Some(notebook_index) = self.notebook_index {
+                // There exists a newline between each cell's source code in the
+                // concatenated source code in Ruff. This newline doesn't actually
+                // exists in the JSON source field.
+                //
+                // Now, certain edits may try to remove this newline, which means
+                // the edit will spill over to the first character of the next cell.
+                // If it does, we need to translate the end location to the last
+                // character of the previous cell.
+                match (
+                    notebook_index.cell(location.line),
+                    notebook_index.cell(end_location.line),
+                ) {
+                    (Some(start_cell), Some(end_cell)) if start_cell != end_cell => {
+                        debug_assert_eq!(end_location.column.get(), 1);
+
+                        let prev_row = end_location.line.saturating_sub(1);
+                        end_location = LineColumn {
+                            line: notebook_index.cell_row(prev_row).unwrap_or(OneIndexed::MIN),
+                            column: self
+                                .source_code
+                                .line_column(self.source_code.line_end_exclusive(prev_row))
+                                .column,
+                        };
+                    }
+                    (Some(_), None) => {
+                        debug_assert_eq!(end_location.column.get(), 1);
+
+                        let prev_row = end_location.line.saturating_sub(1);
+                        end_location = LineColumn {
+                            line: notebook_index.cell_row(prev_row).unwrap_or(OneIndexed::MIN),
+                            column: self
+                                .source_code
+                                .line_column(self.source_code.line_end_exclusive(prev_row))
+                                .column,
+                        };
+                    }
+                    _ => {
+                        end_location = notebook_index.translate_line_column(&end_location);
+                    }
+                }
+                location = notebook_index.translate_line_column(&location);
+            }
+
+            let value = json!({
+                "content": edit.content().unwrap_or_default(),
+                "location": location_to_json(location),
+                "end_location": location_to_json(end_location)
+            });
+
+            s.serialize_element(&value)?;
+        }
+
+        s.end()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use insta::assert_snapshot;
+
+    use crate::message::JsonEmitter;
+    use crate::message::tests::{
+        capture_emitter_notebook_output, capture_emitter_output, create_diagnostics,
+        create_notebook_diagnostics, create_syntax_error_diagnostics,
+    };
+
+    #[test]
+    fn output() {
+        let mut emitter = JsonEmitter;
+        let content = capture_emitter_output(&mut emitter, &create_diagnostics());
+
+        assert_snapshot!(content);
+    }
+
+    #[test]
+    fn syntax_errors() {
+        let mut emitter = JsonEmitter;
+        let content = capture_emitter_output(&mut emitter, &create_syntax_error_diagnostics());
+
+        assert_snapshot!(content);
+    }
+
+    #[test]
+    fn notebook_output() {
+        let mut emitter = JsonEmitter;
+        let (diagnostics, notebook_indexes) = create_notebook_diagnostics();
+        let content =
+            capture_emitter_notebook_output(&mut emitter, &diagnostics, &notebook_indexes);
+
+        assert_snapshot!(content);
+    }
+}
--- a/crates/ruff_linter/src/message/json_lines.rs
+++ b/crates/ruff_linter/src/message/json_lines.rs
@@ -0,0 +1,58 @@
+use std::io::Write;
+
+use crate::message::json::message_to_json_value;
+use crate::message::{Emitter, EmitterContext, OldDiagnostic};
+
+#[derive(Default)]
+pub struct JsonLinesEmitter;
+
+impl Emitter for JsonLinesEmitter {
+    fn emit(
+        &mut self,
+        writer: &mut dyn Write,
+        diagnostics: &[OldDiagnostic],
+        context: &EmitterContext,
+    ) -> anyhow::Result<()> {
+        for diagnostic in diagnostics {
+            serde_json::to_writer(&mut *writer, &message_to_json_value(diagnostic, context))?;
+            writer.write_all(b"\n")?;
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use insta::assert_snapshot;
+
+    use crate::message::json_lines::JsonLinesEmitter;
+    use crate::message::tests::{
+        capture_emitter_notebook_output, capture_emitter_output, create_diagnostics,
+        create_notebook_diagnostics, create_syntax_error_diagnostics,
+    };
+
+    #[test]
+    fn output() {
+        let mut emitter = JsonLinesEmitter;
+        let content = capture_emitter_output(&mut emitter, &create_diagnostics());
+
+        assert_snapshot!(content);
+    }
+
+    #[test]
+    fn syntax_errors() {
+        let mut emitter = JsonLinesEmitter;
+        let content = capture_emitter_output(&mut emitter, &create_syntax_error_diagnostics());
+
+        assert_snapshot!(content);
+    }
+
+    #[test]
+    fn notebook_output() {
+        let mut emitter = JsonLinesEmitter;
+        let (messages, notebook_indexes) = create_notebook_diagnostics();
+        let content = capture_emitter_notebook_output(&mut emitter, &messages, &notebook_indexes);
+
+        assert_snapshot!(content);
+    }
+}
--- a/crates/ruff_linter/src/message/junit.rs
+++ b/crates/ruff_linter/src/message/junit.rs
@@ -3,10 +3,11 @@ use std::path::Path;

 use quick_junit::{NonSuccessKind, Report, TestCase, TestCaseStatus, TestSuite, XmlString};

-use ruff_db::diagnostic::Diagnostic;
 use ruff_source_file::LineColumn;

-use crate::message::{Emitter, EmitterContext, MessageWithLocation, group_diagnostics_by_filename};
+use crate::message::{
+    Emitter, EmitterContext, MessageWithLocation, OldDiagnostic, group_diagnostics_by_filename,
+};

 #[derive(Default)]
 pub struct JunitEmitter;
@@ -15,7 +16,7 @@ impl Emitter for JunitEmitter {
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        context: &EmitterContext,
    ) -> anyhow::Result<()> {
        let mut report = Report::new("ruff");
@@ -43,7 +44,7 @@ impl Emitter for JunitEmitter {
                    } = message;
                    let mut status = TestCaseStatus::non_success(NonSuccessKind::Failure);
                    status.set_message(message.body());
-                    let location = if context.is_notebook(&message.expect_ruff_filename()) {
+                    let location = if context.is_notebook(&message.filename()) {
                        // We can't give a reasonable location for the structured formats,
                        // so we show one that's clearly a fallback
                        LineColumn::default()
--- a/crates/ruff_linter/src/message/mod.rs
+++ b/crates/ruff_linter/src/message/mod.rs
@@ -1,144 +1,334 @@
+use std::cmp::Ordering;
 use std::collections::BTreeMap;
 use std::fmt::Display;
 use std::io::Write;
 use std::ops::Deref;

+use ruff_db::diagnostic::{self as db, Annotation, DiagnosticId, LintName, Severity, Span};
+use ruff_python_parser::semantic_errors::SemanticSyntaxError;
 use rustc_hash::FxHashMap;

-use ruff_db::diagnostic::{
-    Annotation, Diagnostic, DiagnosticId, FileResolver, Input, LintName, SecondaryCode, Severity,
-    Span, UnifiedFile,
-};
-use ruff_db::files::File;
-
+pub use azure::AzureEmitter;
 pub use github::GithubEmitter;
 pub use gitlab::GitlabEmitter;
 pub use grouped::GroupedEmitter;
+pub use json::JsonEmitter;
+pub use json_lines::JsonLinesEmitter;
 pub use junit::JunitEmitter;
 pub use pylint::PylintEmitter;
 pub use rdjson::RdjsonEmitter;
 use ruff_notebook::NotebookIndex;
+use ruff_python_parser::{ParseError, UnsupportedSyntaxError};
 use ruff_source_file::{LineColumn, SourceFile};
-use ruff_text_size::{Ranged, TextRange, TextSize};
+use ruff_text_size::{Ranged, TextLen, TextRange, TextSize};
 pub use sarif::SarifEmitter;
 pub use text::TextEmitter;

 use crate::Fix;
+use crate::codes::NoqaCode;
+use crate::logging::DisplayParseErrorType;
 use crate::registry::Rule;
+use crate::{Locator, Violation};

+mod azure;
 mod diff;
 mod github;
 mod gitlab;
 mod grouped;
+mod json;
+mod json_lines;
 mod junit;
 mod pylint;
 mod rdjson;
 mod sarif;
 mod text;

-/// Creates a `Diagnostic` from a syntax error, with the format expected by Ruff.
+/// `OldDiagnostic` represents either a diagnostic message corresponding to a rule violation or a
+/// syntax error message.
 ///
-/// This is almost identical to `ruff_db::diagnostic::create_syntax_error_diagnostic`, except the
-/// `message` is stored as the primary diagnostic message instead of on the primary annotation, and
-/// `SyntaxError: ` is prepended to the message.
+/// All of the information for syntax errors is captured in the underlying [`db::Diagnostic`], while
+/// rule violations can have the additional optional fields like fixes, suggestions, and (parent)
+/// `noqa` offsets.
 ///
-/// TODO(brent) These should be unified at some point, but we keep them separate for now to avoid a
-/// ton of snapshot changes while combining ruff's diagnostic type with `Diagnostic`.
-pub fn create_syntax_error_diagnostic(
-    span: impl Into<Span>,
-    message: impl std::fmt::Display,
-    range: impl Ranged,
-) -> Diagnostic {
-    let mut diag = Diagnostic::new(
-        DiagnosticId::InvalidSyntax,
-        Severity::Error,
-        format_args!("SyntaxError: {message}"),
-    );
-    let span = span.into().with_range(range.range());
-    diag.annotate(Annotation::primary(span));
-    diag
+/// For diagnostic messages, the [`db::Diagnostic`]'s primary message contains the
+/// [`OldDiagnostic::body`], and the primary annotation optionally contains the suggestion
+/// accompanying a fix. The `db::Diagnostic::id` field contains the kebab-case lint name derived
+/// from the `Rule`.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct OldDiagnostic {
+    pub diagnostic: db::Diagnostic,
+
+    // these fields are specific to rule violations
+    pub fix: Option<Fix>,
+    pub parent: Option<TextSize>,
+    pub(crate) noqa_offset: Option<TextSize>,
+    pub(crate) secondary_code: Option<SecondaryCode>,
 }

-#[expect(clippy::too_many_arguments)]
-pub fn create_lint_diagnostic<B, S>(
-    body: B,
-    suggestion: Option<S>,
-    range: TextRange,
-    fix: Option<Fix>,
-    parent: Option<TextSize>,
-    file: SourceFile,
-    noqa_offset: Option<TextSize>,
-    rule: Rule,
-) -> Diagnostic
-where
-    B: Display,
-    S: Display,
-{
-    let mut diagnostic = Diagnostic::new(
-        DiagnosticId::Lint(LintName::of(rule.into())),
-        Severity::Error,
-        body,
-    );
-
-    if let Some(fix) = fix {
-        diagnostic.set_fix(fix);
-    }
-
-    if let Some(parent) = parent {
-        diagnostic.set_parent(parent);
-    }
-
-    if let Some(noqa_offset) = noqa_offset {
-        diagnostic.set_noqa_offset(noqa_offset);
-    }
-
-    let span = Span::from(file).with_range(range);
-    let mut annotation = Annotation::primary(span);
-    if let Some(suggestion) = suggestion {
-        annotation = annotation.message(suggestion);
-    }
-    diagnostic.annotate(annotation);
-
-    diagnostic.set_secondary_code(SecondaryCode::new(rule.noqa_code().to_string()));
-
-    diagnostic
-}
-
-impl FileResolver for EmitterContext<'_> {
-    fn path(&self, _file: File) -> &str {
-        unimplemented!("Expected a Ruff file for rendering a Ruff diagnostic");
-    }
-
-    fn input(&self, _file: File) -> Input {
-        unimplemented!("Expected a Ruff file for rendering a Ruff diagnostic");
-    }
-
-    fn notebook_index(&self, file: &UnifiedFile) -> Option<NotebookIndex> {
-        match file {
-            UnifiedFile::Ty(_) => {
-                unimplemented!("Expected a Ruff file for rendering a Ruff diagnostic")
-            }
-            UnifiedFile::Ruff(file) => self.notebook_indexes.get(file.name()).cloned(),
+impl OldDiagnostic {
+    pub fn syntax_error(
+        message: impl Display,
+        range: TextRange,
+        file: SourceFile,
+    ) -> OldDiagnostic {
+        let mut diag = db::Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, message);
+        let span = Span::from(file).with_range(range);
+        diag.annotate(Annotation::primary(span));
+        Self {
+            diagnostic: diag,
+            fix: None,
+            parent: None,
+            noqa_offset: None,
+            secondary_code: None,
        }
    }

-    fn is_notebook(&self, file: &UnifiedFile) -> bool {
-        match file {
-            UnifiedFile::Ty(_) => {
-                unimplemented!("Expected a Ruff file for rendering a Ruff diagnostic")
-            }
-            UnifiedFile::Ruff(file) => self.notebook_indexes.get(file.name()).is_some(),
+    #[expect(clippy::too_many_arguments)]
+    pub fn lint<B, S>(
+        body: B,
+        suggestion: Option<S>,
+        range: TextRange,
+        fix: Option<Fix>,
+        parent: Option<TextSize>,
+        file: SourceFile,
+        noqa_offset: Option<TextSize>,
+        rule: Rule,
+    ) -> OldDiagnostic
+    where
+        B: Display,
+        S: Display,
+    {
+        let mut diagnostic = db::Diagnostic::new(
+            DiagnosticId::Lint(LintName::of(rule.into())),
+            Severity::Error,
+            body,
+        );
+        let span = Span::from(file).with_range(range);
+        let mut annotation = Annotation::primary(span);
+        if let Some(suggestion) = suggestion {
+            annotation = annotation.message(suggestion);
        }
+        diagnostic.annotate(annotation);
+
+        OldDiagnostic {
+            diagnostic,
+            fix,
+            parent,
+            noqa_offset,
+            secondary_code: Some(SecondaryCode(rule.noqa_code().to_string())),
+        }
+    }
+
+    /// Create an [`OldDiagnostic`] from the given [`ParseError`].
+    pub fn from_parse_error(
+        parse_error: &ParseError,
+        locator: &Locator,
+        file: SourceFile,
+    ) -> OldDiagnostic {
+        // Try to create a non-empty range so that the diagnostic can print a caret at the right
+        // position. This requires that we retrieve the next character, if any, and take its length
+        // to maintain char-boundaries.
+        let len = locator
+            .after(parse_error.location.start())
+            .chars()
+            .next()
+            .map_or(TextSize::new(0), TextLen::text_len);
+
+        OldDiagnostic::syntax_error(
+            format_args!(
+                "SyntaxError: {}",
+                DisplayParseErrorType::new(&parse_error.error)
+            ),
+            TextRange::at(parse_error.location.start(), len),
+            file,
+        )
+    }
+
+    /// Create an [`OldDiagnostic`] from the given [`UnsupportedSyntaxError`].
+    pub fn from_unsupported_syntax_error(
+        unsupported_syntax_error: &UnsupportedSyntaxError,
+        file: SourceFile,
+    ) -> OldDiagnostic {
+        OldDiagnostic::syntax_error(
+            format_args!("SyntaxError: {unsupported_syntax_error}"),
+            unsupported_syntax_error.range,
+            file,
+        )
+    }
+
+    /// Create an [`OldDiagnostic`] from the given [`SemanticSyntaxError`].
+    pub fn from_semantic_syntax_error(
+        semantic_syntax_error: &SemanticSyntaxError,
+        file: SourceFile,
+    ) -> OldDiagnostic {
+        OldDiagnostic::syntax_error(
+            format_args!("SyntaxError: {semantic_syntax_error}"),
+            semantic_syntax_error.range,
+            file,
+        )
+    }
+
+    // TODO(brent) We temporarily allow this to avoid updating all of the call sites to add
+    // references. I expect this method to go away or change significantly with the rest of the
+    // diagnostic refactor, but if it still exists in this form at the end of the refactor, we
+    // should just update the call sites.
+    #[expect(clippy::needless_pass_by_value)]
+    pub fn new<T: Violation>(kind: T, range: TextRange, file: &SourceFile) -> Self {
+        Self::lint(
+            Violation::message(&kind),
+            Violation::fix_title(&kind),
+            range,
+            None,
+            None,
+            file.clone(),
+            None,
+            T::rule(),
+        )
+    }
+
+    /// Consumes `self` and returns a new `Diagnostic` with the given parent node.
+    #[inline]
+    #[must_use]
+    pub fn with_parent(mut self, parent: TextSize) -> Self {
+        self.set_parent(parent);
+        self
+    }
+
+    /// Set the location of the diagnostic's parent node.
+    #[inline]
+    pub fn set_parent(&mut self, parent: TextSize) {
+        self.parent = Some(parent);
+    }
+
+    /// Consumes `self` and returns a new `Diagnostic` with the given noqa offset.
+    #[inline]
+    #[must_use]
+    pub fn with_noqa_offset(mut self, noqa_offset: TextSize) -> Self {
+        self.noqa_offset = Some(noqa_offset);
+        self
+    }
+
+    /// Returns `true` if `self` is a syntax error message.
+    pub fn is_syntax_error(&self) -> bool {
+        self.diagnostic.id().is_invalid_syntax()
+    }
+
+    /// Returns the name used to represent the diagnostic.
+    pub fn name(&self) -> &'static str {
+        if self.is_syntax_error() {
+            "syntax-error"
+        } else {
+            self.diagnostic.id().as_str()
+        }
+    }
+
+    /// Returns the message body to display to the user.
+    pub fn body(&self) -> &str {
+        self.diagnostic.primary_message()
+    }
+
+    /// Returns the fix suggestion for the violation.
+    pub fn suggestion(&self) -> Option<&str> {
+        self.diagnostic.primary_annotation()?.get_message()
+    }
+
+    /// Returns the offset at which the `noqa` comment will be placed if it's a diagnostic message.
+    pub fn noqa_offset(&self) -> Option<TextSize> {
+        self.noqa_offset
+    }
+
+    /// Returns the [`Fix`] for the diagnostic, if there is any.
+    pub fn fix(&self) -> Option<&Fix> {
+        self.fix.as_ref()
+    }
+
+    /// Returns `true` if the diagnostic contains a [`Fix`].
+    pub fn fixable(&self) -> bool {
+        self.fix().is_some()
+    }
+
+    /// Returns the noqa code for the diagnostic message as a string.
+    pub fn secondary_code(&self) -> Option<&SecondaryCode> {
+        self.secondary_code.as_ref()
+    }
+
+    /// Returns the URL for the rule documentation, if it exists.
+    pub fn to_url(&self) -> Option<String> {
+        if self.is_syntax_error() {
+            None
+        } else {
+            Some(format!(
+                "{}/rules/{}",
+                env!("CARGO_PKG_HOMEPAGE"),
+                self.name()
+            ))
+        }
+    }
+
+    /// Returns the filename for the message.
+    pub fn filename(&self) -> String {
+        self.diagnostic
+            .expect_primary_span()
+            .expect_ruff_file()
+            .name()
+            .to_string()
+    }
+
+    /// Computes the start source location for the message.
+    pub fn compute_start_location(&self) -> LineColumn {
+        self.diagnostic
+            .expect_primary_span()
+            .expect_ruff_file()
+            .to_source_code()
+            .line_column(self.start())
+    }
+
+    /// Computes the end source location for the message.
+    pub fn compute_end_location(&self) -> LineColumn {
+        self.diagnostic
+            .expect_primary_span()
+            .expect_ruff_file()
+            .to_source_code()
+            .line_column(self.end())
+    }
+
+    /// Returns the [`SourceFile`] which the message belongs to.
+    pub fn source_file(&self) -> SourceFile {
+        self.diagnostic
+            .expect_primary_span()
+            .expect_ruff_file()
+            .clone()
+    }
+}
+
+impl Ord for OldDiagnostic {
+    fn cmp(&self, other: &Self) -> Ordering {
+        (self.source_file(), self.start()).cmp(&(other.source_file(), other.start()))
+    }
+}
+
+impl PartialOrd for OldDiagnostic {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ranged for OldDiagnostic {
+    fn range(&self) -> TextRange {
+        self.diagnostic
+            .expect_primary_span()
+            .range()
+            .expect("Expected range for ruff span")
    }
 }

 struct MessageWithLocation<'a> {
-    message: &'a Diagnostic,
+    message: &'a OldDiagnostic,
    start_location: LineColumn,
 }

 impl Deref for MessageWithLocation<'_> {
-    type Target = Diagnostic;
+    type Target = OldDiagnostic;

    fn deref(&self) -> &Self::Target {
        self.message
@@ -146,30 +336,30 @@ impl Deref for MessageWithLocation<'_> {
 }

 fn group_diagnostics_by_filename(
-    diagnostics: &[Diagnostic],
+    diagnostics: &[OldDiagnostic],
 ) -> BTreeMap<String, Vec<MessageWithLocation>> {
    let mut grouped_messages = BTreeMap::default();
    for diagnostic in diagnostics {
        grouped_messages
-            .entry(diagnostic.expect_ruff_filename())
+            .entry(diagnostic.filename().to_string())
            .or_insert_with(Vec::new)
            .push(MessageWithLocation {
                message: diagnostic,
-                start_location: diagnostic.expect_ruff_start_location(),
+                start_location: diagnostic.compute_start_location(),
            });
    }
    grouped_messages
 }

-/// Display format for [`Diagnostic`]s.
+/// Display format for [`OldDiagnostic`]s.
 ///
-/// The emitter serializes a slice of [`Diagnostic`]s and writes them to a [`Write`].
+/// The emitter serializes a slice of [`OldDiagnostic`]s and writes them to a [`Write`].
 pub trait Emitter {
    /// Serializes the `diagnostics` and writes the output to `writer`.
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        context: &EmitterContext,
    ) -> anyhow::Result<()>;
 }
@@ -194,40 +384,101 @@ impl<'a> EmitterContext<'a> {
    }
 }

+/// A secondary identifier for a lint diagnostic.
+///
+/// For Ruff rules this means the noqa code.
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Default, Hash, serde::Serialize)]
+#[serde(transparent)]
+pub struct SecondaryCode(String);
+
+impl SecondaryCode {
+    pub fn new(code: String) -> Self {
+        Self(code)
+    }
+
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+impl Display for SecondaryCode {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+impl std::ops::Deref for SecondaryCode {
+    type Target = str;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl PartialEq<&str> for SecondaryCode {
+    fn eq(&self, other: &&str) -> bool {
+        self.0 == *other
+    }
+}
+
+impl PartialEq<SecondaryCode> for &str {
+    fn eq(&self, other: &SecondaryCode) -> bool {
+        other.eq(self)
+    }
+}
+
+impl PartialEq<NoqaCode> for SecondaryCode {
+    fn eq(&self, other: &NoqaCode) -> bool {
+        &self.as_str() == other
+    }
+}
+
+impl PartialEq<SecondaryCode> for NoqaCode {
+    fn eq(&self, other: &SecondaryCode) -> bool {
+        other.eq(self)
+    }
+}
+
+// for `hashbrown::EntryRef`
+impl From<&SecondaryCode> for SecondaryCode {
+    fn from(value: &SecondaryCode) -> Self {
+        value.clone()
+    }
+}
+
 #[cfg(test)]
 mod tests {
    use rustc_hash::FxHashMap;

-    use ruff_db::diagnostic::Diagnostic;
+    use crate::codes::Rule;
+    use crate::{Edit, Fix};
    use ruff_notebook::NotebookIndex;
    use ruff_python_parser::{Mode, ParseOptions, parse_unchecked};
    use ruff_source_file::{OneIndexed, SourceFileBuilder};
    use ruff_text_size::{TextRange, TextSize};

-    use crate::codes::Rule;
-    use crate::message::{Emitter, EmitterContext, create_lint_diagnostic};
-    use crate::{Edit, Fix};
+    use crate::Locator;
+    use crate::message::{Emitter, EmitterContext, OldDiagnostic};

-    use super::create_syntax_error_diagnostic;
-
-    pub(super) fn create_syntax_error_diagnostics() -> Vec<Diagnostic> {
+    pub(super) fn create_syntax_error_diagnostics() -> Vec<OldDiagnostic> {
        let source = r"from os import

 if call(foo
    def bar():
        pass
 ";
+        let locator = Locator::new(source);
        let source_file = SourceFileBuilder::new("syntax_errors.py", source).finish();
        parse_unchecked(source, ParseOptions::from(Mode::Module))
            .errors()
            .iter()
            .map(|parse_error| {
-                create_syntax_error_diagnostic(source_file.clone(), &parse_error.error, parse_error)
+                OldDiagnostic::from_parse_error(parse_error, &locator, source_file.clone())
            })
            .collect()
    }

-    pub(super) fn create_diagnostics() -> Vec<Diagnostic> {
+    pub(super) fn create_diagnostics() -> Vec<OldDiagnostic> {
        let fib = r#"import os


@@ -245,7 +496,7 @@ def fibonacci(n):
        let fib_source = SourceFileBuilder::new("fib.py", fib).finish();

        let unused_import_start = TextSize::from(7);
-        let unused_import = create_lint_diagnostic(
+        let unused_import = OldDiagnostic::lint(
            "`os` imported but unused",
            Some("Remove unused import: `os`"),
            TextRange::new(unused_import_start, TextSize::from(9)),
@@ -260,7 +511,7 @@ def fibonacci(n):
        );

        let unused_variable_start = TextSize::from(94);
-        let unused_variable = create_lint_diagnostic(
+        let unused_variable = OldDiagnostic::lint(
            "Local variable `x` is assigned to but never used",
            Some("Remove assignment to unused variable `x`"),
            TextRange::new(unused_variable_start, TextSize::from(95)),
@@ -277,7 +528,7 @@ def fibonacci(n):
        let file_2 = r"if a == 1: pass";

        let undefined_name_start = TextSize::from(3);
-        let undefined_name = create_lint_diagnostic(
+        let undefined_name = OldDiagnostic::lint(
            "Undefined name `a`",
            Option::<&'static str>::None,
            TextRange::new(undefined_name_start, TextSize::from(4)),
@@ -292,7 +543,7 @@ def fibonacci(n):
    }

    pub(super) fn create_notebook_diagnostics()
-    -> (Vec<Diagnostic>, FxHashMap<String, NotebookIndex>) {
+    -> (Vec<OldDiagnostic>, FxHashMap<String, NotebookIndex>) {
        let notebook = r"# cell 1
 import os
 # cell 2
@@ -308,7 +559,7 @@ def foo():
        let notebook_source = SourceFileBuilder::new("notebook.ipynb", notebook).finish();

        let unused_import_os_start = TextSize::from(16);
-        let unused_import_os = create_lint_diagnostic(
+        let unused_import_os = OldDiagnostic::lint(
            "`os` imported but unused",
            Some("Remove unused import: `os`"),
            TextRange::new(unused_import_os_start, TextSize::from(18)),
@@ -323,7 +574,7 @@ def foo():
        );

        let unused_import_math_start = TextSize::from(35);
-        let unused_import_math = create_lint_diagnostic(
+        let unused_import_math = OldDiagnostic::lint(
            "`math` imported but unused",
            Some("Remove unused import: `math`"),
            TextRange::new(unused_import_math_start, TextSize::from(39)),
@@ -338,7 +589,7 @@ def foo():
        );

        let unused_variable_start = TextSize::from(98);
-        let unused_variable = create_lint_diagnostic(
+        let unused_variable = OldDiagnostic::lint(
            "Local variable `x` is assigned to but never used",
            Some("Remove assignment to unused variable `x`"),
            TextRange::new(unused_variable_start, TextSize::from(99)),
@@ -391,7 +642,7 @@ def foo():

    pub(super) fn capture_emitter_output(
        emitter: &mut dyn Emitter,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
    ) -> String {
        let notebook_indexes = FxHashMap::default();
        let context = EmitterContext::new(&notebook_indexes);
@@ -403,7 +654,7 @@ def foo():

    pub(super) fn capture_emitter_notebook_output(
        emitter: &mut dyn Emitter,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        notebook_indexes: &FxHashMap<String, NotebookIndex>,
    ) -> String {
        let context = EmitterContext::new(notebook_indexes);
--- a/crates/ruff_linter/src/message/pylint.rs
+++ b/crates/ruff_linter/src/message/pylint.rs
@@ -1,10 +1,9 @@
 use std::io::Write;

-use ruff_db::diagnostic::Diagnostic;
 use ruff_source_file::OneIndexed;

 use crate::fs::relativize_path;
-use crate::message::{Emitter, EmitterContext};
+use crate::message::{Emitter, EmitterContext, OldDiagnostic};

 /// Generate violations in Pylint format.
 /// See: [Flake8 documentation](https://flake8.pycqa.org/en/latest/internal/formatters.html#pylint-formatter)
@@ -15,17 +14,16 @@ impl Emitter for PylintEmitter {
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        context: &EmitterContext,
    ) -> anyhow::Result<()> {
        for diagnostic in diagnostics {
-            let filename = diagnostic.expect_ruff_filename();
-            let row = if context.is_notebook(&filename) {
+            let row = if context.is_notebook(&diagnostic.filename()) {
                // We can't give a reasonable location for the structured formats,
                // so we show one that's clearly a fallback
                OneIndexed::from_zero_indexed(0)
            } else {
-                diagnostic.expect_ruff_start_location().line
+                diagnostic.compute_start_location().line
            };

            let body = if let Some(code) = diagnostic.secondary_code() {
@@ -37,7 +35,7 @@ impl Emitter for PylintEmitter {
            writeln!(
                writer,
                "{path}:{row}: {body}",
-                path = relativize_path(&filename),
+                path = relativize_path(&*diagnostic.filename()),
            )?;
        }

--- a/crates/ruff_linter/src/message/rdjson.rs
+++ b/crates/ruff_linter/src/message/rdjson.rs
@@ -4,12 +4,11 @@ use serde::ser::SerializeSeq;
 use serde::{Serialize, Serializer};
 use serde_json::{Value, json};

-use ruff_db::diagnostic::Diagnostic;
 use ruff_source_file::SourceCode;
 use ruff_text_size::Ranged;

 use crate::Edit;
-use crate::message::{Emitter, EmitterContext, LineColumn};
+use crate::message::{Emitter, EmitterContext, LineColumn, OldDiagnostic};

 #[derive(Default)]
 pub struct RdjsonEmitter;
@@ -18,7 +17,7 @@ impl Emitter for RdjsonEmitter {
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        _context: &EmitterContext,
    ) -> anyhow::Result<()> {
        serde_json::to_writer_pretty(
@@ -38,7 +37,7 @@ impl Emitter for RdjsonEmitter {
 }

 struct ExpandedMessages<'a> {
-    diagnostics: &'a [Diagnostic],
+    diagnostics: &'a [OldDiagnostic],
 }

 impl Serialize for ExpandedMessages<'_> {
@@ -57,23 +56,23 @@ impl Serialize for ExpandedMessages<'_> {
    }
 }

-fn message_to_rdjson_value(message: &Diagnostic) -> Value {
-    let source_file = message.expect_ruff_source_file();
+fn message_to_rdjson_value(message: &OldDiagnostic) -> Value {
+    let source_file = message.source_file();
    let source_code = source_file.to_source_code();

-    let start_location = source_code.line_column(message.expect_range().start());
-    let end_location = source_code.line_column(message.expect_range().end());
+    let start_location = source_code.line_column(message.start());
+    let end_location = source_code.line_column(message.end());

    if let Some(fix) = message.fix() {
        json!({
            "message": message.body(),
            "location": {
-                "path": message.expect_ruff_filename(),
+                "path": message.filename(),
                "range": rdjson_range(start_location, end_location),
            },
            "code": {
                "value": message.secondary_code(),
-                "url": message.to_ruff_url(),
+                "url": message.to_url(),
            },
            "suggestions": rdjson_suggestions(fix.edits(), &source_code),
        })
@@ -81,12 +80,12 @@ fn message_to_rdjson_value(message: &Diagnostic) -> Value {
        json!({
            "message": message.body(),
            "location": {
-                "path": message.expect_ruff_filename(),
+                "path": message.filename(),
                "range": rdjson_range(start_location, end_location),
            },
            "code": {
                "value": message.secondary_code(),
-                "url": message.to_ruff_url(),
+                "url": message.to_url(),
            },
        })
    }
--- a/crates/ruff_linter/src/message/sarif.rs
+++ b/crates/ruff_linter/src/message/sarif.rs
@@ -5,12 +5,11 @@ use anyhow::Result;
 use serde::{Serialize, Serializer};
 use serde_json::json;

-use ruff_db::diagnostic::{Diagnostic, SecondaryCode};
 use ruff_source_file::OneIndexed;

 use crate::VERSION;
 use crate::fs::normalize_path;
-use crate::message::{Emitter, EmitterContext};
+use crate::message::{Emitter, EmitterContext, OldDiagnostic, SecondaryCode};
 use crate::registry::{Linter, RuleNamespace};

 pub struct SarifEmitter;
@@ -19,7 +18,7 @@ impl Emitter for SarifEmitter {
    fn emit(
        &mut self,
        writer: &mut dyn Write,
-        diagnostics: &[Diagnostic],
+        diagnostics: &[OldDiagnostic],
        _context: &EmitterContext,
    ) -> Result<()> {
        let results = diagnostics
@@ -123,10 +122,10 @@ struct SarifResult<'a> {

 impl<'a> SarifResult<'a> {
    #[cfg(not(target_arch = "wasm32"))]
-    fn from_message(message: &'a Diagnostic) -> Result<Self> {
-        let start_location = message.expect_ruff_start_location();
-        let end_location = message.expect_ruff_end_location();
-        let path = normalize_path(&*message.expect_ruff_filename());
+    fn from_message(message: &'a OldDiagnostic) -> Result<Self> {
+        let start_location = message.compute_start_location();
+        let end_location = message.compute_end_location();
+        let path = normalize_path(&*message.filename());
        Ok(Self {
            code: message.secondary_code(),
            level: "error".to_string(),
@@ -143,10 +142,10 @@ impl<'a> SarifResult<'a> {

    #[cfg(target_arch = "wasm32")]
    #[expect(clippy::unnecessary_wraps)]
-    fn from_message(message: &'a Diagnostic) -> Result<Self> {
-        let start_location = message.expect_ruff_start_location();
-        let end_location = message.expect_ruff_end_location();
-        let path = normalize_path(&*message.expect_ruff_filename());
+    fn from_message(message: &'a OldDiagnostic) -> Result<Self> {
+        let start_location = message.compute_start_location();
+        let end_location = message.compute_end_location();
+        let path = normalize_path(&*message.filename());
        Ok(Self {
            code: message.secondary_code(),
            level: "error".to_string(),
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderazuretests__output.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderazuretests__output.snap
@@ -1,6 +1,7 @@
 ---
-source: crates/ruff_db/src/diagnostic/render/azure.rs
-expression: env.render_diagnostics(&diagnostics)
+source: crates/ruff_linter/src/message/azure.rs
+expression: content
+snapshot_kind: text
 ---
 ##vso[task.logissue type=error;sourcepath=fib.py;linenumber=1;columnnumber=8;code=F401;]`os` imported but unused
 ##vso[task.logissue type=error;sourcepath=fib.py;linenumber=6;columnnumber=5;code=F841;]Local variable `x` is assigned to but never used
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderazuretests__syntax_errors.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderazuretests__syntax_errors.snap
@@ -1,6 +1,7 @@
 ---
-source: crates/ruff_db/src/diagnostic/render/azure.rs
-expression: env.render_diagnostics(&diagnostics)
+source: crates/ruff_linter/src/message/azure.rs
+expression: content
+snapshot_kind: text
 ---
 ##vso[task.logissue type=error;sourcepath=syntax_errors.py;linenumber=1;columnnumber=15;]SyntaxError: Expected one or more symbol names after import
 ##vso[task.logissue type=error;sourcepath=syntax_errors.py;linenumber=3;columnnumber=12;]SyntaxError: Expected ')', found newline
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderjsontests__notebook_output.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderjsontests__notebook_output.snap
@@ -1,6 +1,7 @@
 ---
-source: crates/ruff_db/src/diagnostic/render/json.rs
-expression: env.render_diagnostics(&diagnostics)
+source: crates/ruff_linter/src/message/json.rs
+expression: content
+snapshot_kind: text
 ---
 [
  {
@@ -83,8 +84,8 @@ expression: env.render_diagnostics(&diagnostics)
        {
          "content": "",
          "end_location": {
-            "column": 1,
-            "row": 5
+            "column": 10,
+            "row": 4
          },
          "location": {
            "column": 1,
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderjsontests__output.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderjsontests__output.snap
@@ -1,6 +1,7 @@
 ---
-source: crates/ruff_db/src/diagnostic/render/json.rs
-expression: env.render_diagnostics(&diagnostics)
+source: crates/ruff_linter/src/message/json.rs
+expression: content
+snapshot_kind: text
 ---
 [
  {
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderjsontests__syntax_errors.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrenderjsontests__syntax_errors.snap
@@ -1,6 +1,7 @@
 ---
-source: crates/ruff_db/src/diagnostic/render/json.rs
-expression: env.render_diagnostics(&diagnostics)
+source: crates/ruff_linter/src/message/json.rs
+expression: content
+snapshot_kind: text
 ---
 [
  {
--- a/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrender__json_linestestsnotebook_output.snap
+++ b/crates/ruff_db/src/diagnostic/render/snapshots/ruff_dbdiagnosticrender__json_linestestsnotebook_output.snap
@@ -1,7 +1,8 @@
 ---
-source: crates/ruff_db/src/diagnostic/render/json_lines.rs
-expression: env.render_diagnostics(&diagnostics)
+source: crates/ruff_linter/src/message/json_lines.rs
+expression: content
+snapshot_kind: text
 ---
 {"cell":1,"code":"F401","end_location":{"column":10,"row":2},"filename":"notebook.ipynb","fix":{"applicability":"safe","edits":[{"content":"","end_location":{"column":10,"row":2},"location":{"column":1,"row":2}}],"message":"Remove unused import: `os`"},"location":{"column":8,"row":2},"message":"`os` imported but unused","noqa_row":2,"url":"https://docs.astral.sh/ruff/rules/unused-import"}
 {"cell":2,"code":"F401","end_location":{"column":12,"row":2},"filename":"notebook.ipynb","fix":{"applicability":"safe","edits":[{"content":"","end_location":{"column":1,"row":3},"location":{"column":1,"row":2}}],"message":"Remove unused import: `math`"},"location":{"column":8,"row":2},"message":"`math` imported but unused","noqa_row":2,"url":"https://docs.astral.sh/ruff/rules/unused-import"}
-{"cell":3,"code":"F841","end_location":{"column":6,"row":4},"filename":"notebook.ipynb","fix":{"applicability":"unsafe","edits":[{"content":"","end_location":{"column":1,"row":5},"location":{"column":1,"row":4}}],"message":"Remove assignment to unused variable `x`"},"location":{"column":5,"row":4},"message":"Local variable `x` is assigned to but never used","noqa_row":4,"url":"https://docs.astral.sh/ruff/rules/unused-variable"}
+{"cell":3,"code":"F841","end_location":{"column":6,"row":4},"filename":"notebook.ipynb","fix":{"applicability":"unsafe","edits":[{"content":"","end_location":{"column":10,"row":4},"location":{"column":1,"row":4}}],"message":"Remove assignment to unused variable `x`"},"location":{"column":5,"row":4},"message":"Local variable `x` is assigned to but never used","noqa_row":4,"url":"https://docs.astral.sh/ruff/rules/unused-variable"}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Zanie Blue	40b4aa28f9	Zizmor	2025-07-03 07:23:11 -05:00
Zanie Blue	ea4bf00c23	Revert "Only run the relevant test" This reverts commit 82dc27f2680b8085280136848ffe2ee1d2952a4e.	2025-07-03 07:01:28 -05:00
Zanie Blue	7f4aa4b3fb	Update for Depot	2025-07-03 07:01:28 -05:00
Zanie Blue	34c98361ae	Do not set `TMP`	2025-07-03 07:01:28 -05:00
Zanie Blue	38bb96a6c2	Remove log variables	2025-07-03 07:01:28 -05:00
Zanie Blue	a014d55455	Remove fuzz corpus hack	2025-07-03 07:01:27 -05:00
Zanie Blue	306f6f17a9	Enable more logs	2025-07-03 07:01:27 -05:00
Zanie Blue	b233888f00	Only run the relevant test	2025-07-03 07:01:27 -05:00
Zanie Blue	540cbd9085	Add debug logs?	2025-07-03 07:01:27 -05:00
Zanie Blue	0112f7f0e4	Use a dev drive for testing on Windows	2025-07-03 07:01:27 -05:00