testing-guidelines

Testing Guidelines

Test Types

• Unit tests

  • Fast, isolated, no network or DB.
  • Test one behavior per test.

• Integration tests

  • Exercise real integrations (DB, queue, external service stubs).
  • Focus on critical paths and failure modes.

• End-to-end (E2E) tests

  • Cover full user journeys.
  • More expensive; keep the set small but meaningful.

Naming & Structure

• Test files:
  • Mirror source structure: src/foo/bar.ts → tests/foo/bar.test.ts
• Test names:
  • Use descriptive names reflecting behavior, e.g.:
    • it("rejects requests without authentication")

Coverage Expectations

• Core domain logic: [e.g., ≥ 90% line coverage]
• Peripheral or legacy code: [e.g., best-effort; prioritize stability]
• Do not chase metrics blindly; focus on risk and impact.

Fixtures & Data

• Prefer factory functions over static fixtures.
• Make fixtures explicit and readable; avoid hidden magic.

Testing Conventions

• Arrange-Act-Assert structure where possible.
• Avoid brittle tests that depend on:
  • Exact error messages
  • Implementation details that can change safely

CI Requirements

• All tests must pass before merge.
• E2E tests may run on a separate pipeline if slow; document behavior.