Testing

The testing philosophy: test the logic that can be wrong, not framework plumbing. The money math is pure, isolated in src/domain/, and tested exhaustively with no mocks. Thin query/mutation hooks, the Supabase client, and presentation are deliberately not unit-tested.

Commands

npm test              # run all unit tests
npm run test:watch    # watch mode
npm run test:ci       # with coverage (what CI runs)
npm run e2e           # Maestro end-to-end flows

Unit tests (Jest)

Tests live next to the code they cover (*.test.ts). Coverage is scoped to the pure modules - domain, application/overview, data/repositories/mappers, and shared/date/clock - with thresholds enforced in CI:

Metric	Threshold
Lines	85%
Statements	85%
Branches	80%
Functions	80%

Current coverage sits around 96%. If you add logic to the domain, add a test alongside it or CI will fail on the threshold.

Jest is pinned to v29

Expo SDK 56's jest-expo preset is built on Jest 29 internals. Jest 30 throws clearMocksOnScope is not a function against it, so the project pins Jest to ^29.

End-to-end tests (Maestro)

Flows in e2e/ drive the real UI. They require a built app on a simulator/emulator and a configured Supabase project.

# Install Maestro once
curl -fsSL "https://get.maestro.mobile.dev" | bash

# Run a single flow
maestro test e2e/onboarding.yaml

Flow	Journey
onboarding.yaml	Create a household from a clean state
set-budget-and-add-expense.yaml	Set the budget, log an expense, see it on Home
settle.yaml	The weekly settlement view renders

Run onboarding.yaml first; the others assume an existing household. The add-expense button is targeted by testID: add-expense.

For the full approach and known gaps, see the Test strategy.