[Python] Type checking in CI

.github/workflows/build.yml

@@ -148,9 +148,6 @@ jobs:
         with:
           dotnet-version: "10.0.x"
 
-      - name: Setup dotnet tools
-        run: dotnet tool restore
-
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v6
         with:

.github/workflows/python-type-checking.yml

@@ -0,0 +1,106 @@
+name: Python Type Checking
+
+on:
+  pull_request:
+    branches: [main]
+    paths:
+      - 'src/Fable.Transforms/Python/**'
+      - 'src/fable-library-py/**'
+      - 'tests/Python/**'
+      - 'pyrightconfig.ci.json'
+      - 'pyproject.toml'
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  pyright:
+    runs-on: ubuntu-latest
+    env:
+      UV_LINK_MODE: copy
+
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v5
+        with:
+          dotnet-version: "10.0.x"
+
+      - name: Setup dotnet tools
+        run: dotnet tool restore
+
+      - name: Set up Python 3.12
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.12"
+
+      - name: Install uv
+        run: |
+          pipx install uv
+          pipx install maturin
+
+      - name: Build Python (compile only)
+        run: ./build.sh test python --compile-only
+
+      - name: Run Pyright (standard mode)
+        id: pyright
+        continue-on-error: true
+        run: |
+          if uv run pyright --project pyrightconfig.ci.json temp/tests/Python/ temp/fable-library-py/; then
+            echo "result=:white_check_mark: All non-excluded files pass" >> $GITHUB_OUTPUT
+            echo "passed=true" >> $GITHUB_OUTPUT
+          else
+            echo "result=:x: Type errors found in non-excluded files" >> $GITHUB_OUTPUT
+            echo "passed=false" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Get excluded files
+        id: excluded
+        run: |
+          COUNT=$(grep -c '"temp/' pyrightconfig.ci.json || echo "0")
+          echo "count=$COUNT" >> $GITHUB_OUTPUT
+          FILES=$(grep '"temp/' pyrightconfig.ci.json | sed 's/.*"temp/temp/' | sed 's/".*//' | sort)
+          echo "files<<EOF" >> $GITHUB_OUTPUT
+          echo "$FILES" >> $GITHUB_OUTPUT
+          echo "EOF" >> $GITHUB_OUTPUT
+
+      - name: Find existing comment
+        uses: peter-evans/find-comment@v3
+        id: find-comment
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: 'github-actions[bot]'
+          body-includes: Python Type Checking
+
+      - name: Create or update PR comment
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
+          issue-number: ${{ github.event.pull_request.number }}
+          edit-mode: replace
+          body: |
+            ## Python Type Checking (Pyright) Results
+
+            ${{ steps.pyright.outputs.result }}
+
+            |     Metric     |                Value                |
+            | -------------- | ----------------------------------- |
+            | Excluded files | ${{ steps.excluded.outputs.count }} |
+
+            <details>
+            <summary>Files excluded from type checking</summary>
+
+            These files have known type errors and are excluded from CI. Remove from `pyrightconfig.ci.json` as errors are fixed.
+
+            ```
+            ${{ steps.excluded.outputs.files }}
+            ```
+
+            </details>
+
+      - name: Fail if type errors
+        if: false  # Temporarily disabled
+        # if: steps.pyright.outputs.passed == 'false'
+        run: exit 1

pyrightconfig.ci.json

@@ -0,0 +1,13 @@
+{
+  "extends": "./pyrightconfig.json",
+  "exclude": [
+    "**/.venv/**",
+    "**/node_modules/**",
+    "temp/fable-library-py/fable_library/list.py",
+    "temp/tests/Python/test_applicative.py",
+    "temp/tests/Python/test_map.py",
+    "temp/tests/Python/test_misc.py",
+    "temp/tests/Python/test_type.py",
+    "temp/tests/Python/fable_modules/thoth_json_python/encode.py"
+  ]
+}

src/Fable.Build/FableLibrary/Python.fs

@@ -6,7 +6,7 @@ open Build.Utils
 open SimpleExec
 open BlackFox.CommandLine
 
-type BuildFableLibraryPython() =
+type BuildFableLibraryPython(?skipCore: bool) =
     inherit
         BuildFableLibrary(
             language = "python",
@@ -16,6 +16,8 @@ type BuildFableLibraryPython() =
             outDir = Path.Combine("temp", "fable-library-py", "fable_library")
         )
 
+    let skipCore = defaultArg skipCore false
+
     override this.CopyStage() =
         // Copy all Python/F# files to the build directory
         Directory.GetFiles(this.LibraryDir, "*") |> Shell.copyFiles this.BuildDir
@@ -33,7 +35,11 @@ type BuildFableLibraryPython() =
     override this.PostFableBuildStage() =
         // Install the python dependencies at the root of the project
         Command.Run("uv", "sync", this.BuildDir) // Maturin needs a local virtual environment
-        Command.Run("uv", "run maturin develop --release", this.BuildDir)
+
+        if skipCore then
+            printfn "Skipping fable-library-core (Rust) build"
+        else
+            Command.Run("uv", "run maturin develop --release", this.BuildDir)
 
         // Fix issues with Fable .fsproj not supporting links, so we need to copy the
         // files ourself to the output directory
@@ -44,7 +50,7 @@ type BuildFableLibraryPython() =
 
         Shell.deleteDir (this.BuildDir </> "fable_library/fable-library-ts")
 
-        // Run Ruff linter checking import sorting and fix any issues
-        Command.Run("uv", $"run ruff check --select I --fix {this.BuildDir}")
+        // Run Ruff linter checking import sorting, removing unused imports, and fix any issues
+        Command.Run("uv", $"run ruff check --select I,F401 --fix {this.BuildDir}")
         // Run Ruff formatter on all generated files
         Command.Run("uv", $"run ruff format {this.BuildDir}")

src/Fable.Build/Main.fs

@@ -63,7 +63,8 @@ Available commands:
             --threaded              Compile and run the tests with the threaded runtime
 
         Options for Python:
-            --typing                Run type checking with Pyright and show the summary
+            --type-check            Run type checking on the generated code with Pyright
+            --format                Format the code generated code with Ruff formatter
 
     standalone                      Compile standalone + worker version of Fable running
                                     on top of of Node.js

src/Fable.Build/Quicktest/Python.fs

@@ -10,10 +10,12 @@ open Build.Utils
 let private fableLibraryBuildDir = Path.Resolve("temp", "fable-library-py")
 
 let handle (args: string list) =
+    let skipFableLibraryCore = args |> List.contains "--skip-fable-library-core"
+
     // Install local fable-library as editable package for testing
     // This ensures quicktest uses the locally built version, not PyPI
     if not (args |> List.contains "--skip-fable-library") then
-        BuildFableLibraryPython().Run(false)
+        BuildFableLibraryPython(skipCore = skipFableLibraryCore).Run(false)
         // Install fable-library in editable mode
         Command.Run("uv", $"pip install -e {fableLibraryBuildDir}")
 

src/Fable.Build/Test/Python.fs

@@ -12,12 +12,13 @@ let private fableLibraryBuildDir = Path.Resolve("temp", "fable-library-py")
 
 let handle (args: string list) =
     let skipFableLibrary = args |> List.contains "--skip-fable-library"
+    let skipFableLibraryCore = args |> List.contains "--skip-fable-library-core"
     let isWatch = args |> List.contains "--watch"
     let noDotnet = args |> List.contains "--no-dotnet"
-    let runTyping = args |> List.contains "--typing"
+    let runTyping = args |> List.contains "--type-check"
     let runFormat = args |> List.contains "--format"
 
-    BuildFableLibraryPython().Run(skipFableLibrary)
+    BuildFableLibraryPython(skipCore = skipFableLibraryCore).Run(skipFableLibrary)
 
     Directory.clean buildDir
 
@@ -40,7 +41,7 @@ let handle (args: string list) =
                 if isWatch then
                     let ruffCmd =
                         if runFormat then
-                            $"uv run ruff check --select I --fix {buildDir} && uv run ruff format {buildDir} && "
+                            $"uv run ruff check --select I,F401 --fix {buildDir} && uv run ruff format {buildDir} && "
                         else
                             ""
 
@@ -71,8 +72,8 @@ let handle (args: string list) =
         Command.Fable(fableArgs, workingDirectory = buildDir)
 
         if runFormat then
-            // Run Ruff linter checking import sorting and fix any issues
-            Command.Run("uv", $"run ruff check --select I --fix {buildDir}")
+            // Run Ruff linter checking import sorting and fix any issues, and remove unused imports
+            Command.Run("uv", $"run ruff check --select I,F401 --fix {buildDir}")
             // Run Ruff formatter on all generated files
             Command.Run("uv", $"run ruff format {buildDir}")
 
@@ -104,4 +105,4 @@ let handle (args: string list) =
 
             printfn "Pyright summary: %s" summaryLine
         else
-            printfn "Skipping type checking (use --typing to enable)"
+            printfn "Skipping type checking (use --type-check to enable)"