Add MyPy type checking and a GitHub Action to automatically check this.

.github/workflows/mypy.yml

@@ -0,0 +1,22 @@
+---
+name: Run mypy
+on:
+  pull_request:
+  push:
+    branches: ["main", "v[0-9]*"]
+    tags: ["v[0-9]*"]
+  workflow_dispatch:
+jobs:
+  mypy:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: apt update
+        run: sudo apt update
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+      - name: Install Python dependencies
+        run: |
+          python -m pip install --upgrade pip wheel
+          pip install -r requirements-dev.txt
+      - name: MyPy
+        run: mypy .

mypy.ini

@@ -0,0 +1,26 @@
+[mypy]
+plugins = mypy_django_plugin.main
+# TODO: Check all code in the future
+check_untyped_defs = False
+disallow_any_generics = False
+disallow_incomplete_defs = False
+disallow_subclassing_any = False
+disallow_untyped_calls = False
+disallow_untyped_defs = False
+ignore_missing_imports = True
+no_implicit_optional = True
+no_implicit_reexport = True
+strict = True
+warn_return_any = False
+# TODO: Remove this exception in the future
+disable_error_code = var-annotated
+
+[mypy.plugins.django-stubs]
+django_settings_module = "tests.test_settings.settings_5_0"
+
+# TODO: Type check tests in the future
+[mypy-tests.*]
+ignore_errors = True
+
+[mypy-docs.*]
+ignore_errors = True

requirements-dev.txt

@@ -1,5 +1,9 @@
 # Requirements for developing (not just using) the package
 
+django-stubs
 hatch
+mypy
 pre-commit
+requests
 tox<4
+types-requests