# Test Design

> Design practical tests for business logic, integrations, APIs, and regression protection.

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

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# Test Design

## Purpose

Produce a lean, useful test plan for a change or component — enough coverage to catch the failures that matter, not enough to drown the change under fixture maintenance.

## Test types

- **Unit tests** for pure logic and small functions.
- **Component tests** for module-level behavior with realistic dependencies.
- **Integration tests** for database, queue, API, or external boundaries.
- **Acceptance-style tests** for user-visible behavior or contract surfaces.

## Output format

```md
## Scope

## Test plan

### Unit
### Component
### Integration
### Acceptance

## Edge and failure cases

## Tests intentionally not included
```

## Rules

- Prefer meaningful coverage over coverage theater.
- Tests must be runnable by the project's existing tooling.
- Include edge cases and failure cases — happy-path-only suites lie about quality.
- Avoid brittle tests that assert implementation details without protecting behavior.
- If a test type is intentionally skipped, name it in "Tests intentionally not included" and say why.