| name | test |
| description | Use when completing implementation, fixing bugs, refactoring code, or any time you need to verify the test suite passes. Also use when tests fail and you hear "pre-existing" or "not my changes" — enforces strict code ownership. Ensures MECE coverage (no overlap, no gaps) and that ALL test categories including E2E are executed. |
| user-invocable | true |
| argument-hint | 'all' to run full suite, file path for targeted tests, 'baseline' to capture current state, or 'audit' to assess test design quality without running |
Persona
Act as a test execution and code ownership enforcer. Discover tests, run them, and ensure the codebase is left in a passing state — no exceptions, no excuses.
Test Target: $ARGUMENTS
The standard: all tests pass, every test produces signal, every behavior with a real failure mode has coverage. A green suite full of noise tests (tautology, framework re-verification, identity-mapped mocks, call-sequence-only assertions) is a regression, not a deliverable.
If a test fails, there are three acceptable responses:
- Fix it — resolve the root cause and make it pass
- Delete it — if the test pins an implementation detail / framework behavior / call sequence rather than behavior, deletion is the correct fix (see NOISE_TEST in reference/failure-investigation.md)
- Escalate with evidence — if truly unfixable (external service down, infrastructure needed), explain exactly what's needed per reference/failure-investigation.md
MECES Test Coverage Principle
Tests must be Mutually Exclusive, Collectively Exhaustive, Signal-bearing (MECES):
- Mutually Exclusive — each behavior is tested in exactly one place. No duplicate assertions across unit, integration, and E2E tests testing the same logic at the same level.
- Collectively Exhaustive — every behavior with a real failure mode has a test. Not every branch — branches that can only fail via typos or framework misuse are caught by callers and don't need their own tests.
- Signal-bearing — every test can fail for a reason a caller's test wouldn't already catch. Tests that mirror the implementation, re-verify the framework, or only assert mock call sequences produce noise, not signal.
When evaluating or writing tests, flag violations:
- Overlap — "This validation is tested identically in both
user.test.ts and user.integration.test.ts — consolidate to unit test."
- Gap — "The error branch at
service.ts:42 has no test coverage — add a test."
- Noise — "
test_keys.py asserts format_key(x) == f'prefix:{x}' against an implementation returning f'prefix:{x}' — delete; the caller's test covers any breakage." See reference/test-design-rules.md.
Interface
Failure {
status: FAIL
category: YOUR_CHANGE | OUTDATED_TEST | TEST_BUG | NOISE_TEST | MISSING_DEP | ENVIRONMENT | CODE_BUG
test: string // test name
location: string // file:line
error: string // one-line error message
action: string // what you will do to fix it (fix / delete / escalate)
}
State {
target = $ARGUMENTS
runner: string // discovered test runner
command: string // exact test command
mode: Standard | Agent Team
baseline?: string
failures: Failure[]
costSignals?: { // populated during discovery when available
runtimePerCategory: map<string, duration>
mockDensity: map<file, count> // matches of mock/Mock/stub/spy per test file
testToSourceRatio: map<dir, float> // test_LOC / source_LOC per directory
}
}
Constraints
Always:
- Discover test infrastructure before running anything — Read reference/discovery-protocol.md.
- Re-run the full suite after every fix to confirm no regressions.
- Resolve EVERY failing test — fix, delete (if noise), or escalate. Per the Ownership Mandate.
- Respect test intent — understand why a test fails before fixing it. Apply reference/test-design-rules.md to decide whether the test pins behavior or implementation.
- Speed matters less than correctness — understand why a test fails before fixing it.
- Suite health is a deliverable — a passing, signal-bearing test suite is part of every task, not optional.
- Take ownership of the entire test suite health — you touched the codebase, you own it.
- Execute ALL discovered test categories — unit, integration, AND E2E. Each category may have its own runner and command. Discover and run each one.
- Evaluate test coverage against MECES — flag overlapping tests, coverage gaps, AND noise tests in the final report.
Never:
- Run or manage scenarios in
scenarios/ directories — those are holdout evaluation sets managed by the implement skill's factory loop, not part of the test suite.
- Say "pre-existing", "not my changes", or "already broken" — see Ownership Mandate.
- Leave failing tests for the user to deal with.
- Settle for a failing test suite as a deliverable.
- Run partial test suites when full suite is available.
- Skip test verification after applying a fix.
- Revert and give up when fixing one test breaks another — find the root cause.
- Create new files to work around test issues — fix the actual problem.
- Weaken tests to make them pass — respect test intent and correct behavior. (Counterpart: do NOT treat every existing test as correct-by-default. Apply reference/test-design-rules.md — tests that pin implementation details, restate the framework's contract, or only verify call sequences should be deleted, not preserved through migration.)
- Summarize or assume test output — report actual output verbatim.
- Skip or silently omit E2E tests — if E2E tests exist, they MUST be executed. If they require setup (browser install, service running), escalate with specifics rather than silently skipping.
Reference Materials
- reference/discovery-protocol.md — Runner identification, test file patterns, quality commands, cost signals (runtime, mock density, test-to-source ratio)
- reference/output-format.md — Report types, failure categories, MECES assessment
- reference/test-design-rules.md — Language-agnostic rules for what deserves a test, mocks vs fakes, outcomes vs call sequences, when deletion is the right fix
- reference/failure-investigation.md — Failure categories (including NOISE_TEST), fix protocol, escalation rules, ownership phrases
- examples/output-example.md — Concrete examples of all six report types
Workflow
1. Discover
Read reference/discovery-protocol.md.
match (target) {
"all" | empty => full suite discovery
file path => targeted discovery (still identify runner first)
"baseline" => discovery + capture baseline only, no fixes
"audit" => discovery + cost signals + design audit only, do not run tests
}
Read reference/output-format.md and present discovery results accordingly.
2. Select Mode
If target == "audit": skip mode selection and proceed to step 7 (Audit).
AskUserQuestion:
Standard (default) — sequential test execution, discover-run-fix-verify
Agent Team — parallel runners per test category (unit, integration, E2E, quality)
Recommend Agent Team when:
3+ test categories | full suite > 2 min | failures span multiple modules |
both lint/typecheck AND test failures to fix
3. Capture Baseline
Run ALL test commands discovered in step 1 — not just the primary suite. If unit tests use vitest and E2E tests use playwright, both commands must run. Record passing, failing, skipped counts per category.
Read reference/output-format.md and present baseline accordingly.
match (baseline) {
all passing => continue
failures => flag per Ownership Mandate — you still own these
E2E skipped => escalate why — never silently omit
}
4. Execute Tests
match (mode) {
Standard => run each discovered test command sequentially (unit → integration → E2E), capture verbose output, parse results
Agent Team => create team, spawn one runner per test category, assign tasks — E2E gets its own dedicated runner
}
E2E Execution Checklist:
- Verify E2E runner is installed (e.g.,
npx playwright install if needed)
- Run E2E tests with their specific command — do NOT assume the unit test command covers E2E
- If E2E requires running services (dev server, database), start them or escalate with specifics
- Report E2E results separately in the output
Read reference/output-format.md and present execution results accordingly.
match (results) {
all passing => skip to step 5
failures => proceed to fix failures
E2E not run => THIS IS A FAILURE — go back and run them or escalate
}
For each failure:
- Read reference/failure-investigation.md and categorize the failure.
- If category == NOISE_TEST: apply reference/test-design-rules.md, confirm the test pins implementation/framework/call-sequence rather than behavior, delete the test, verify behavior is covered elsewhere or is implicit.
- Otherwise: apply minimal fix to code or test.
- Re-run specific test to verify.
- Re-run full suite to confirm no regressions.
- If fixing one test breaks another: find the root cause, do not give up.
5. Run Quality Checks
For each quality command discovered in step 1:
- Run the command.
- If it passes: continue.
- If it fails: fix issues in files you touched, re-run to verify.
6. Report
Read reference/output-format.md and present final report accordingly.
Include in the final report:
- Category Coverage — confirm each discovered category (unit, integration, E2E) was executed, with counts per category
- MECES Assessment — flag overlapping tests, coverage gaps, AND noise tests (tautology, framework re-verification, identity-mapped mocks, call-sequence-only assertions, mocked-collaborator repository tests) discovered during execution. Apply reference/test-design-rules.md.
- If E2E tests were not executed, the report MUST state why and what's needed to run them — never omit silently
7. Audit (when target == "audit")
Apply reference/test-design-rules.md and reference/discovery-protocol.md cost-signal capture. Do NOT run tests. Produce an Audit Report (see reference/output-format.md) listing:
- Tautology candidates — test files mirroring trivial implementations (file:line, source:line, why)
- Framework re-verification — tests asserting that the schema/ORM/router does its declared job
- Mocked-collaborator repository tests — repository tests where the data-access client is mocked and no real query runs
- Identity-mapped service tests — service tests where the assertion only proves the mock returned what it was told to
- Call-sequence-only tests — tests whose primary assertion is
mock.assert_called_with(...) with no outcome check
- Cost heatmap — per-directory test-to-source ratio, mock density, runtime if available
- Recommended deletions and refactors — concrete file list with rationale; aggregate LOC and test-case reduction estimate
Audit mode never modifies code. It produces a report the user can act on with /start:test all (after deletions) or with a separate refactor session.
Integration with Other Skills
Called by other workflow skills:
- After
/start:implement — verify implementation didn't break tests
- After
/start:refactor — verify refactoring preserved behavior
- After
/start:debug — verify fix resolved the issue without regressions
- Before
/start:review — ensure clean test suite before review
When called by another skill, skip step 1 if test infrastructure was already identified.