# Test Engineering

> Design and implement high-signal unit, integration, end-to-end, property, and regression tests for changed behavior.

- Skill: `nafeeur/test-engineering` (Agent Skill)
- Install (CLI): `npx skillmds@latest add nafeeur/test-engineering`
- Raw SKILL.md: https://api.skillmd.com/api/skills/nafeeur/test-engineering/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Integrations & APIs
- Author: nafeeur (https://skillmd.com/u/nafeeur)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/nafeeur/test-engineering

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# Test Engineering

- Derive tests from contracts and failure modes, not implementation details.
- Prefer integration tests for orchestration and tool/agent behavior; use unit tests for deterministic transforms and parsers.
- Include cancellation, timeouts, partial output, malformed responses, unavailable dependencies, and retries where relevant.
- Keep fixtures minimal and deterministic. Never depend on live production services in default tests.
- Assert complete results and externally visible behavior where practical.
- Record the exact commands used and distinguish skipped environmental checks from passing tests.