Testing Patterns

Unit, integration, and E2E testing patterns with framework-specific guidance. Write tests that catch bugs, not tests that pass — confidence through coverage, speed through isolation.

What's Inside

• Testing pyramid with ratio, speed, and confidence breakdown
• Unit testing patterns (Arrange-Act-Assert, Given-When-Then, parameterized, snapshot, property-based)
• Test doubles guide (stubs, mocks, spies, fakes) with when-to-use guidance
• Parameterized tests across TypeScript, Python, and Go
• Integration testing patterns (transaction rollback, fixtures, factory functions, testcontainers)
• API testing with Supertest
• Mocking best practices (mock boundaries not implementations, dependency injection)
• Framework quick reference (Jest, Vitest, Playwright, Cypress, pytest, Go testing, Rust, JUnit, RSpec, PHPUnit, xUnit)
• Test quality checklist (deterministic, isolated, fast, readable, maintainable, focused)
• Coverage strategy with targets by project type
• Test organization conventions
• Anti-patterns catalog

When to Use

• Writing tests for new or existing code
• Adding test coverage to a project
• Defining a testing strategy
• Fixing flaky tests or improving test quality
• Choosing the right test doubles and patterns

Installation

npx add https://github.com/wpank/ai/tree/main/skills/testing/testing-patterns

Manual Installation

Cursor (per-project)

From your project root:

mkdir -p .cursor/skills
cp -r ~/.ai-skills/skills/testing/testing-patterns .cursor/skills/testing-patterns

Cursor (global)

mkdir -p ~/.cursor/skills
cp -r ~/.ai-skills/skills/testing/testing-patterns ~/.cursor/skills/testing-patterns

Claude Code (per-project)

From your project root:

mkdir -p .claude/skills
cp -r ~/.ai-skills/skills/testing/testing-patterns .claude/skills/testing-patterns

Claude Code (global)

mkdir -p ~/.claude/skills
cp -r ~/.ai-skills/skills/testing/testing-patterns ~/.claude/skills/testing-patterns

Related Skills

• e2e-testing-patterns — Dedicated E2E patterns with Playwright and Cypress
• testing-workflow — Meta-skill that orchestrates testing across a project
• quality-gates — Coverage thresholds and CI/CD enforcement
• clean-code — Code quality standards that tests verify

Part of the Testing skill category.