Add GitHub workflow

.github/workflows/test.yml

@@ -0,0 +1,63 @@
+name: Test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    name: Test on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v5
+        with:
+          enable-cache: true
+
+      - name: Set up Python
+        run: uv python install 3.11
+
+      - name: Install LibreOffice (Ubuntu)
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libreoffice
+
+      - name: Install LibreOffice (macOS)
+        if: runner.os == 'macOS'
+        run: brew install --cask libreoffice
+
+      - name: Install LibreOffice (Windows)
+        if: runner.os == 'Windows'
+        run: choco install libreoffice-still -y --no-progress
+
+      - name: Add LibreOffice to PATH (Windows)
+        if: runner.os == 'Windows'
+        shell: pwsh
+        run: echo "C:\Program Files\LibreOffice\program" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+
+      - name: Confirm soffice is available
+        run: soffice --version
+
+      - name: Install dependencies
+        run: uv sync --all-extras
+
+      - name: Lint (ruff)
+        run: uv run ruff check src tests
+
+      - name: Format check (ruff)
+        run: uv run ruff format --check src tests
+
+      - name: Type check (mypy)
+        run: uv run mypy src/
+
+      - name: Run tests
+        run: uv run python -m testsweet tests/

.gitignore

@@ -2,7 +2,6 @@
 __pycache__/
 *.py[cod]
 *.egg-info/
-.pytest_cache/
 .ruff_cache/
 
 # uv / venvs

CLAUDE.md

@@ -3,7 +3,7 @@
 ## Layout
 
 - `src/sheetwright/` — library + CLI entry points
-- `tests/` — pytest tests, mirroring the package layout
+- `tests/` — testsweet tests, mirroring the package layout
 - `claude/specs/` — design specifications
 - `claude/plans/` — implementation plans (when written)
 
@@ -18,27 +18,29 @@
 ## Python and tooling
 
 - Python 3.11 (`.python-version`)
+
+`python` must be run using `uv run python ...`
+
 - [`uv`](https://docs.astral.sh/uv/) is the project manager — use
   `uv sync` to install, `uv run <cmd>` to run, `uv add <pkg>` to add
   runtime deps, `uv add --dev <pkg>` for dev deps. Don't edit
   `pyproject.toml` dependency lists by hand unless you also know to
   update `uv.lock`.
+
 - [`ruff`](https://docs.astral.sh/ruff/) is the formatter/linter.
   **Run `uv run ruff format <changed-files>` before every commit.**
   Project style is `line-length = 79` and `quote-style = 'single'` —
   use single quotes in new code; ruff format will fix mixed quoting.
+
 - [`mypy`](https://mypy.readthedocs.io/) checks type annotations.
   **Run `uv run mypy src/` before committing changes that add or
   modify type annotations.** Public functions and CLI entry points
   must have type hints; mypy must pass before commit.
 
-`python` must be run using `uv run python ...`
-
-## Testing
-
-Use [testsweet](https://github.com/kaapstorm/testsweet). For links to
-documentation, see its
-[README.md](https://raw.githubusercontent.com/kaapstorm/testsweet/refs/heads/main/README.md).
+- [testsweet](https://github.com/kaapstorm/testsweet) is the test library.
+  **Run `uv run python -m testsweet tests/` to verify changes.**
+  For links to documentation, see the testsweet
+  [README.md](https://raw.githubusercontent.com/kaapstorm/testsweet/refs/heads/main/README.md).
 
 ## Code style
 

README.md

@@ -4,7 +4,7 @@ A toolkit that lets [Claude Code](https://claude.com/claude-code) work with
 spreadsheets the way it works with code: text-source files, git, TDD,
 diffs, and review.
 
-`.xlsx` is treated as a build artefact compiled from text sources. You
+`.xlsx` is treated as a build artifact compiled from text sources. You
 write Markdown tables and YAML sidecars; sheetwright produces the
 workbook and runs [LibreOffice Calc](https://www.libreoffice.org/) in
 headless mode (the default, swappable calc engine) to evaluate every
@@ -46,9 +46,15 @@ uv sync
 uv run sheetwright --help
 ```
 
-LibreOffice must be on `$PATH` for the default calc engine
-(Debian/Ubuntu: `apt install libreoffice`; macOS:
-`brew install --cask libreoffice`).
+LibreOffice must be on `PATH` for the default calc engine.
+
+- Debian/Ubuntu: `apt install libreoffice`
+- macOS: `brew install --cask libreoffice`
+- Windows (PowerShell):
+  `winget install --id TheDocumentFoundation.LibreOffice`
+
+Windows users new to the command line should start with the
+[Windows setup primer](docs/tutorials/windows-setup.md).
 
 ## Documentation
 

claude/specs/2026-04-25_sheetwright-design.md

@@ -127,13 +127,13 @@ draw values from it); small sheets stay fully in `.md`.
 
 ### Version control
 
-| Versioned                                    | Ignored                                  |
-|----------------------------------------------|------------------------------------------|
-| `sheetwright.toml`, `workbook.toml`         | `build/` (built xlsx)                    |
-| `sheets/*.md`, `sheets/*.yaml`               | `.sheetwright/` (built SQLite, caches)  |
-| `data/*.csv`, `data/_schema.sql`             |                                          |
-| `tests/*.py`                                 |                                          |
-| `imports/*.xlsx` (opt-in via `--archive`)    |                                          |
+| Versioned                                 | Ignored                                |
+|-------------------------------------------|----------------------------------------|
+| `sheetwright.toml`, `workbook.toml`       | `build/` (built xlsx)                  |
+| `sheets/*.md`, `sheets/*.yaml`            | `.sheetwright/` (built SQLite, caches) |
+| `data/*.csv`, `data/_schema.sql`          |                                        |
+| `tests/*.py`                              |                                        |
+| `imports/*.xlsx` (opt-in via `--archive`) |                                        |
 
 ## Workflows