add mypy action

.github/workflows/mypy.yml

@@ -0,0 +1,36 @@
+name: Run mypy
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  mypy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Set up Python
+        uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b # v5.3.0
+        with:
+          python-version-file: pyproject.toml
+
+      - name: Install hatch
+        run: pip install hatch --upgrade
+
+      - name: Set up reviewdog
+        if: github.event_name == 'pull_request'
+        uses: reviewdog/action-setup@3f401fe1d58fe77e10d665ab713057375e39b887 # v1.3.0
+
+      - name: Run mypy
+        if: github.event_name != 'pull_request'
+        run: hatch run mypy geometer
+
+      - name: Run mypy with reviewdog
+        if: github.event_name == 'pull_request'
+        env:
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: hatch run mypy geometer | reviewdog -f=mypy -name=mypy -tee -reporter=github-pr-check -filter-mode nofilter

.pre-commit-config.yaml

@@ -32,3 +32,4 @@ repos:
     hooks:
       - id: python-check-blanket-noqa
       - id: python-check-blanket-type-ignore
+      - id: text-unicode-replacement-char