/test-coverage

Jest · Vitest · Playwright All frameworks Writes tests

A comprehensive test coverage audit that runs your coverage tool, maps every untested code path by risk, writes the missing tests using your existing framework and patterns, and optionally enforces coverage thresholds. It doesn’t introduce new libraries — it works entirely within what you already have set up.

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Usage

/test-coverage

To generate the coverage report without writing any tests:

/test-coverage audit only

To run a specific subset of phases:

/test-coverage --phase 1-4

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What it does

Phase	What Claude does
1 — Setup discovery	Identifies test runner (Jest/Vitest/Playwright), config file, coverage provider, file conventions, and all existing test files
2 — Run coverage	Runs jest --coverage or vitest run --coverage, parses the JSON summary, maps every uncovered line and branch per file
3 — Map untested paths	For each source file: happy path, error paths, every conditional branch, edge cases (null/empty/zero), async rejections, guard clauses, side effects
4 — Prioritise	Ranks gaps as P0 (auth/payment/mutations), P1 (utilities/API handlers/validation), P2 (UI components), P3 (trivial/presentational)
5 — Write unit tests	Writes P0 and P1 tests following your existing patterns — Arrange/Act/Assert, real assertions not mock assertions, no new libraries
6 — Write integration tests	If an integration suite exists, adds endpoint tests: valid input, invalid input, missing auth, ownership enforcement
7 — Write component tests	If a component test suite exists, adds tests for conditional rendering, interactions, and prop variations
8 — Generate report	Produces test-coverage-YYYY-MM-DD.md with before/after coverage, gaps addressed, remaining gaps, and infrastructure recommendations
9 — Enforce thresholds	If no coverageThreshold is configured, adds a safe floor (5% below current level) as a commented-out block in the test config

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Report generated

test-coverage-YYYY-MM-DD.md — created in the current directory (not committed)

# Test Coverage Report
Date | Test runner | Coverage before → after

## Summary
## Files with zero tests
## Coverage gaps addressed (file / path / test written / priority)
## Remaining gaps (P2/P3 — not auto-written)
## Recommendations

Tip

Coverage before and after is included in the report so you can measure the exact improvement from each run.

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What gets written automatically

Auto-written (P0 and P1 gaps):

• Unit tests for every auth/payment/mutation code path
• Unit tests for all utility and pure functions
• Unit tests for API route handlers (happy path + error path)
• Unit tests for form validation logic and data transformations
• Integration tests for untested endpoints (if integration suite exists)
• Component tests for untested conditional rendering and interactions (if component suite exists)

Flagged with recommendation (not auto-written):

• P2/P3 gaps (trivial getters, pure presentational components)
• Tests that would require creating a new test infrastructure from scratch
• Test coverage for third-party library wrappers with no added logic

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Standards enforced

Every test written by this command follows these rules:

• Uses your existing framework — no new npm install or library introductions
• Follows your file convention — co-located *.test.ts, __tests__/, or tests/ root, matching what’s already there
• Uses your existing mocks — jest.mock, vi.mock, __mocks__/, MSW — whichever pattern is already in use
• Tests behaviour, not implementation — asserts observable output, not that a specific private method was called
• Human-readable test names — it("returns null when the user has no active subscription") not it("works")
• No real network calls — all external dependencies (database, API, email) are mocked

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Framework support

Test runner	Notes
Jest	✅ Full support — jest --coverage, jest.config.ts, jest.config.js
Vitest	✅ Full support — vitest run --coverage, vitest.config.ts
Playwright (API testing)	✅ Integration tests for API endpoints
Cypress	✅ Component tests and API tests if suite exists
Testing Library	✅ Used for React/Vue/Svelte component tests
No test runner set up	⚠ Claude will identify the gaps and recommend a setup — it will not auto-configure a test runner from scratch

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Install

git clone https://github.com/Oladiman/iron-scrolls.git
cd iron-scrolls
bash install.sh

View raw command source →