Initial pyright config and turn on type-checking in CI

.github/workflows/main.yml

@@ -34,6 +34,24 @@ env:
 
 
 jobs:
+  pyright:
+    strategy:
+      matrix:
+        python:
+        - "3.8"
+        - "3.11"
+        - "3.12"
+        platform:
+        - ubuntu-latest
+        - macos-latest
+        - windows-latest
+    runs-on: ${{ matrix.platform }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: jakebailey/pyright-action@v2
+        with:
+          python-version: ${{ matrix.python }}
+
   test:
     strategy:
       matrix:

pyrightconfig.json

@@ -0,0 +1,31 @@
+{
+	"$schema": "https://raw.githubusercontent.com/microsoft/pyright/main/packages/vscode-pyright/schemas/pyrightconfig.schema.json",
+	"exclude": [
+		"build",
+		".tox",
+		"**/extern", // Vendored
+		"**/_vendor", // Vendored
+		"setuptools/_distutils", // Vendored
+		"**/tests", // Disabled as long as analyzeUnannotatedFunctions=false to reduce log spam
+		"**/_*", // Disabled as long as analyzeUnannotatedFunctions=false to reduce log spam
+	],
+	// CI should test for all versions, local development gets hints for oldest supported
+	"pythonVersion": "3.8",
+	// For now we don't mind if mypy's `type: ignore` comments accidentally suppresses pyright issues
+	"enableTypeIgnoreComments": true,
+	"typeCheckingMode": "basic",
+	// For now, align with mypy's default of skipping unnanotated functions, only care about public API which should be annotated
+	"analyzeUnannotatedFunctions": false,
+	// TODO: Test environment is not yet properly configured to install all imported packages
+	"reportMissingImports": "none",
+	// Too many issues caused by vendoring and dynamic patching, still worth fixing when we can
+	"reportAttributeAccessIssue": "warning",
+	// Defered initialization (initialize_options/finalize_options) causes many "potentially None" issues
+	// TODO: Fix with type-guards or by changing how it's initialized
+	"reportCallIssue": "warning",
+	"reportArgumentType": "warning",
+	"reportOptionalIterable": "warning",
+	"reportOptionalMemberAccess": "warning",
+	"reportGeneralTypeIssues": "warning",
+	"reportOptionalOperand": "warning",
+}