Test.
Red-green-refactor discipline. Edge case matrices. Vitest. Playwright. E2E patterns. Coverage that means something.
TDD Superbrain.
Most tests are written AFTER the code, which means they test what was written, not what was needed. This skill enforces test-first: write the failing test, see it fail, write minimum code to pass, refactor with green test. Plus: edge case matrix generation, Vitest config patterns, Playwright E2E setup, and coverage that excludes auto-generated code.
Four recipes.
Red-green-refactor
RED: write a failing test that captures the requirement. GREEN: write the minimum code to make it pass (do not over-engineer). REFACTOR: improve structure with the test as safety net. Repeat.
Edge case matrix
For each input: empty, null, undefined, zero, negative, max int, unicode, very long, with newlines, with special chars. Generate the matrix BEFORE writing the test.
Vitest patterns
describe nesting for context. beforeEach reset state. vi.mock for module mocks. vi.useFakeTimers for time-dependent. Snapshot tests ONLY for stable serialization.
Playwright E2E
One test per critical user journey. Page Object Model for reusable selectors. Wait for state, not timeouts. Screenshot diff for visual regression.
It composes.
Skills compose into workflows. Test is rarely the only skill you will use — it pairs naturally with these others in the library.
One command.
Installs only stryx-test (skip the other 19) into ~/.claude/skills/stryx-test/.
Free for all use.
Stryx Labs License v1.0. Use Test in personal, commercial, internal, and production work. No attribution required.