Mock Data Skill: Realistic Fixtures From Your Real Schema
Generates fixtures from your Prisma, SQL, or TS schema with happy-path, edge, and boundary rows. Mock data tends to test the happy path and nothing else, which is why edge cases first appear in production.
Full Prompt
An installable mock-data skill. Reads the schema in this repo and emits a fixture file with happy-path rows plus boundary rows for tests.
What It Does
- Reads your schema — Prisma, SQL, Zod, or OpenAPI
- Three tiers — happy path, edge cases, boundaries
- Deterministic values — no random data, fixtures stay stable across runs
- Foreign-key safe — emitted in correct load order
Install in 30 Seconds
Pick your tool above and download:
- Claude Code:
~/.claude/skills/mock-data/SKILL.md - OpenAI Codex CLI: append to
AGENTS.md - Cursor: append to
.cursorrules
Same content, three install paths. Reload and ask for the audit on your next change.
Why This Skill Earns Its Keep
Mock data tends to test the happy path and nothing else, which is why edge cases first appear in production. This skill forces a boundary row and an edge row into every fixture set so the test suite gets at least one nudge against the corners.
Install once, run before every push.