ci: Add CI workflow for testing with multiple Python versions

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.11", "3.12"]
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Install uv
+      uses: astral-sh/setup-uv@v6
+      with:
+        version: "latest"
+        python-version: ${{ matrix.python-version }}
+
+    - name: Install dependencies
+      run: uv sync --dev
+
+    - name: Run ruff check
+      run: uv run ruff check
+
+    - name: Run ruff format check
+      run: uv run ruff format --check
+
+    - name: Run mypy
+      run: uv run mypy src/
+
+    - name: Run tests with coverage
+      run: uv run pytest --cov=langdiff --cov-fail-under=75

CLAUDE.md

@@ -25,6 +25,13 @@ uv run pytest -v                # Verbose output
 uv run pytest -k "test_name"    # Run specific test by name pattern
 ```
 
+### Code Coverage
+```bash
+uv run pytest --cov=langdiff --cov-fail-under=75  # Run tests with 75% coverage requirement
+uv run pytest --cov=langdiff --cov-report=term-missing  # Show missing lines in detail
+uv run pytest --cov=langdiff                      # Basic coverage report
+```
+
 ### Linting and Formatting
 ```bash
 uv run ruff check              # Check for linting issues
@@ -100,4 +107,4 @@ Development dependencies:
 Documentation dependencies:
 - `mkdocs`: Static site generator
 - `mkdocs-material`: Material Design theme for MkDocs
-- `mkdocstrings[python]`: Auto-generate API docs from docstrings
+- `mkdocstrings[python]`: Auto-generate API docs from docstrings

pyproject.toml

@@ -34,12 +34,26 @@ exclude = [
 
 [dependency-groups]
 dev = [
+    "mypy>=1.17.1",
     "openai>=1.99.1",
     "pytest>=8.4.1",
+    "pytest-cov>=6.2.1",
     "ruff>=0.12.8",
 ]
 docs = [
     "mkdocs>=1.6.0",
     "mkdocs-material>=9.5.0",
     "mkdocstrings[python]>=0.26.0",
 ]
+
+[tool.coverage.run]
+source = ["src"]
+omit = ["tests/*"]
+
+[tool.coverage.report]
+exclude_lines = [
+    "pragma: no cover",
+    "def __repr__",
+    "raise AssertionError",
+    "raise NotImplementedError",
+]