Summary
This handles test isolation by replacing dependencies with mocks, stubs, and spies so you can unit test without hitting real databases, APIs, or file systems. It covers Jest for JavaScript/TypeScript, unittest.mock for Python, and Mockito for Java, plus patterns for things like simulating errors and verifying interactions. The guidance on mocking at boundaries (repositories, services) rather than mocking everything you own is solid advice that will keep your tests maintainable. Best used when you need fast, deterministic tests and want to avoid the brittleness that comes from over-mocking internal implementation details.
Install to Claude Code
npx -y skills add aj-geddes/useful-ai-prompts --skill mocking-stubbing --agent claude-codeInstalls into .claude/skills of the current project.
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SKILL.md
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Plug Mailtrap into your AI workflow and let it handle the email.
Connect Mailtrap MCP →Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →Make coding agent sessions - Searchable, Shareable, Vendor-neutral & Scored.
Try For Free →Your agent targets a perfect 10 Code Health score. Deterministic. Every commit.
Try For Free →Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →belt cli automatically finds the best tools and skills for your agent. image, video, music, tts...
one prompt install →
