# Write Tests

> Add, revise, or review Marin tests for an explicit behavior change, regression, or test-quality request.

- Skill: `marin-community/write-tests` (Agent Skill)
- Install (CLI): `npx skillmds@latest add marin-community/write-tests`
- Raw SKILL.md: https://api.skillmd.com/api/skills/marin-community/write-tests/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: marin-community (https://skillmd.com/u/marin-community)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/marin-community/write-tests

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# Write tests

Read root `TESTING.md` before writing or reviewing tests. For tests under
`lib/*`, also read the nearest module `AGENTS.md` and every testing guide it
references.

Treat those files as the source of truth for behavioral value, test style,
fakes and mocks, timing, numerical tolerances, markers, and commands.