Write Test

Write Tests

0. Detect the framework

• Run .claude/tools/facts.sh — it reports the detected test framework. Write in THAT framework, in its idiom (see rules/test-frameworks.md). Don't introduce a second framework; don't hand-roll asserts/mocks it already ships.
• None configured? Pick the canonical default for the stack and say why in one line.

1. Read the source

• Understand every public function's contract
• Identify edge cases from the implementation (not just happy path)

2. Design test cases (before writing any code)

For each function, list:

• Happy path (normal input → expected output)
• Boundary (empty, zero, max, nil/null)
• Error path (invalid input, resource failure)
• Concurrency (if the function touches shared state)

Present the test plan. Wait for approval.

3. Write

• Table-driven / parameterized tests in the detected framework's idiom (Go subtests, rstest, it.each, pytest.mark.parametrize)
• Property-based tests for anything parsing external input (Hypothesis, proptest, fast-check, testing/quick)
• One test function per behavior, not per source function
• Test names describe the scenario: test_login_rejects_expired_token
• No test depends on another test's state
• No sleep() — use channels, signals, or mocks

4. Verify

• All new tests pass
• All existing tests still pass
• No flaky tests (run 3 times)
• Report coverage delta