Frontend#

cd frontend
npm run test            # Vitest
npm run test:coverage   # with the lcov report SonarCloud consumes
npm run lint            # oxlint
npm run build           # tsc -b && vite build

App.test.tsx renders the board against a stubbed fetch and checks what the user sees and does in each state: signed out, signed in, adding, completing, deleting, clearing, and each way the backend can refuse. mockApi routes on the method as well as the path, because list, create, update and delete all share the /api/tasks URL and only the method tells them apart.

Two details are deliberate:

• Fixture dates are computed from the real today, not hardcoded. The board reads the clock once on mount and groups rows by how far away they are, so a fixed date would change which section a row lands in as time passed, and the suite would rot quietly.
• The loading-state test holds the board's own fetch open rather than letting the stub resolve straight away. Loading is transient, and asserting it against an immediate stub is a race that passes on timing rather than on behaviour — it did, until it did not.

dates.test.ts covers the due-date logic directly rather than through the DOM. It is the only pure logic in the frontend and the only place an off-by-one can hide: "Today", "Tomorrow", a weekday name and a plain date are each one day apart. It includes a daylight-saving case, because building a Date from yyyy-mm-dd at local midnight gets the answer wrong by a day across a clock change — which is why every function there takes today as an argument and anchors its arithmetic at UTC.