write-tests

name	write-tests
description	Guidance for writing meaningful unit and integration tests.

Skill: Write Tests

Purpose

Produce maintainable tests that validate behavior, not implementation, to give the team confidence to ship and refactor.

Prerequisites

• Acceptance criteria are clear.
• Testing stack is specified in TECH.md.

Checklist

1. Test Cases: Enumerate test cases from acceptance criteria: happy path, error paths, and edge cases.
2. Structure (AAA): Structure each test using Arrange-Act-Assert.
   • Arrange: Set up inputs and mocks.
   • Act: Invoke the code under test.
   • Assert: Verify the outcome.
3. Naming: Name tests descriptively, like should <do something> when <condition>.
4. Focus: Focus on a single assertion per test where possible.
5. Behavior, not Implementation: Test what the code does, not how it does it.
6. Integration Tests: Test contracts at boundaries (HTTP, DB). Use real or in-memory implementations where practical. Cover auth paths. Reset state between tests.
7. General: Don't skip failing tests—fix or delete them. Co-locate tests with source files.

Quality Bar

• Every acceptance criterion is tested.
• All scenarios (happy, error, edge) are covered.
• Tests are isolated and deterministic (no network calls or global state).