[UnsignedArduino]

Summary

Unit coverage of src/mkcd2app goes from 42% to 66%. All new tests run offline: redun tasks are called through .func(...), and run_cmd, clone_and_checkout, requests.get and get_sim_html_path are monkeypatched, so no npm, mkc or network access is needed. Unit and e2e tests now also run as separate CI workflows.

Tooling

• Adds pytest-cov as a dev dependency. Coverage runs on every pytest run (--no-cov turns it off), configured in pyproject.toml.
• Adds tests/conftest.py, which marks each test unit or e2e by its directory, so uv run pytest -m unit runs only the fast tests (~3s). Also turns on --strict-markers. A test outside tests/unit and tests/e2e fails collection, because it would otherwise run in neither CI workflow.
• There is only one conftest.py, because mypy fails when two modules are both named conftest. Shared test helpers are in tests/unit/helpers.py.

CI

• New unit.yaml ("Unit tests"): uv run pytest -m unit with coverage, on ubuntu/windows/macos. It skips the Node.js setup step, since the unit tests don't need Node.
• e2e.yaml ("E2E tests") now runs only uv run pytest -m e2e --no-cov. Coverage would read ~0% there anyway, because the tests drive the mkcd2app executable in a subprocess.
• The two workflows run in parallel and neither waits for the other. Check names are now unit (<os>) and, unchanged, e2e (<os>). If branch protection requires specific checks, add the unit ones.

New tests

File	Covers	Module coverage
test_website.py	copying and filling the real bundled template (title, favicon inlining, package.json, input left unmodified, old output replaced), install_website_deps, both website builds including relative node_modules/.bin symlinks	website.py 23% → 100%
test_code.py	fetch_code for all five source types, _warn_on_target_mismatch, build_binary_js, copy_support_files with path icon, URL icon and HTTP error	code.py 25% → 100%
test_redun_compat.py	Windows drive-letter get_proto patch; folder hashes ignore mtime but change on file edit, add, remove, rename and path change (checked that the mtime tests fail on unpatched redun)	_redun_compat.py 58% → 100%
test_meta_comment.py, test_paths.py, test_run.py, test_filesystem.py, test_resources.py	extract_meta_comment, the MKCD2APP_HOME override and every path helper, run_cmd (success, cwd, BuildError, which_path), rmtree_robust with read-only files, bundled resources	each at 100% except text.py (82%)

Deliberately not covered here: is_strict_semver, and title formatting and escaping in fill_website_template. Those are known bugs being fixed separately, and that fix will add their tests. Still untested: cli.py, main.py, the build_project wiring, and the toolchain/target install tasks. These are listed in PROJECT_CONTEXT.md.

CLAUDE.md and docs/PROJECT_CONTEXT.md are updated to match.

Test plan

• uv run ruff check ., uv run ruff format --check ., uv run mypy .: clean
• uv run pytest locally on Linux: 153 passed (148 unit + 5 e2e)
• CI on ubuntu/windows/macos green at 06130e9, before the workflow split
• A stray tests/test_stray.py fails collection with a clear error
• CI green with the split workflows at 8925378: unit and e2e on all three OSes, plus lint

🤖 Generated with Claude Code

https://claude.ai/code/session_01Mbb9ZdHu1tFP2ZhM62pbgq