Test

Testing Workflow

Delegates to the Tester agent for test coverage and verification.

Workflow

1. Identify - Determine what needs testing (component, hook, utility, integration)
2. Write - Create test files colocated with source (e.g., button.test.tsx)
3. Run - Execute tests and verify results
4. Report - Summarize coverage and gaps

Testing Priorities

1. Critical paths - Auth, payments, core features
2. Edge cases - Error states, empty states, boundaries
3. User interactions - Forms, buttons, navigation
4. Integration points - API calls, external services

Rationalization Counters

If you catch yourself thinking any of the following, STOP — you are skipping testing:

| Rationalization | Why It's Wrong | |---|---| | "This is too simple to test" | Simple functions with edge cases are exactly what tests catch | | "I'll add tests later" | Later never comes; untested code ships and breaks | | "The types guarantee correctness" | Types check structure, not logic — add(a, b) returning a - b passes TypeScript | | "It's just UI, tests don't help" | Interaction tests catch regressions that visual review misses | | "Manual testing is enough" | Manual testing doesn't run in CI and doesn't prevent regressions | | "Tests are passing immediately" | Tests that pass on first run without failing first may not be testing what you think — verify the test actually exercises the code path |

Red Flags

• Tests pass immediately on first write: Suspicious. Verify the test would fail if the implementation were wrong.
• No assertions: A test without assertions is not a test.
• Mocking everything: If you mock the thing you're testing, you're testing the mock.

Output

Return a summary:

• Tests written: New test files/cases
• Tests passing: Status
• Coverage: Key areas covered
• Gaps: What still needs testing

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Variant: TDD (test-first discipline)

A test-first discipline that produces tests which describe behavior through public interfaces, not implementation. Such tests survive refactors. Tests coupled to internals do not — they break the moment you rename a function and pass when behavior actually breaks.

Before exploring the codebase, follow [../context-doc/DOMAIN-AWARENESS.md](../context-doc/DOMAIN-AWARENESS.md). Test names and interface vocabulary should match the project's CONTEXT.md.

Anti-pattern: horizontal slices

Do not write all tests first, then all implementation. That produces tests describing imagined behavior. They test the shape of things (data structures, function signatures) instead of user-facing capability. They go insensitive to real changes — they pass when behavior breaks and fail when behavior is fine.

WRONG (horizontal):
  RED:   test1, test2, test3, test4, test5
  GREEN: impl1, impl2, impl3, impl4, impl5

RIGHT (vertical):
  RED→GREEN: test1 → impl1
  RED→GREEN: test2 → impl2
  ...

Each cycle responds to what you learned from the previous one. You can only write the right test for behavior N after implementing behavior N−1.

Workflow

1. Plan

Before writing any code:

• Confirm with the user what interface changes are needed
• Confirm which behaviors to test (prioritize — you can't test everything)
• List the behaviors to test (not implementation steps)
• Get user approval on the plan

Ask: "What should the public interface look like? Which behaviors are most important?"

2. Tracer bullet

Write one test confirming one thing about the system:

RED:   test for first behavior → fails
GREEN: minimal code to pass → passes

This proves the path works end-to-end. Don't move on until it passes.

3. Incremental loop

For each remaining behavior:

RED:   next test → fails
GREEN: minimal code to pass → passes

To run the red→green cycle autonomously across turns, set /goal every planned behavior has a passing test and the full suite exits 0. The evaluator reads the test output from the transcript after each turn — don't phrase the condition as something only the runtime can prove (file flags, etc.).

Rules:

• One test at a time
• Only enough code to pass the current test
• Don't anticipate future tests
• Keep tests focused on observable behavior

4. Refactor

After all tests pass, look for cleanup:

• Extract duplication
• Deepen modules — move complexity behind simple interfaces
• Apply naming from CONTEXT.md
• Run the full test suite after each refactor step

Never refactor while red. Get to green first.

Per-cycle checklist

• [ ] Test describes behavior, not implementation
• [ ] Test uses only the public interface
• [ ] Test would survive an internal refactor
• [ ] Code is minimal for this test
• [ ] No speculative features added

When TDD is the wrong tool

• One-shot scripts, prototypes, throwaway exploration
• UI work where the "behavior" is visual and a snapshot/visual test is more useful
• Code where the public interface is dictated by an external spec (just write the conformance test, then implement)

For these, use /build (scaffold-then-test) or /fix (existing-bug pipeline) instead.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: darkroomengineering
• Source: darkroomengineering/cc-settings
• License: MIT

Install and usage instructions live in the source repository linked above.