How does this skill improve test reliability?

It prevents 'fragile tests' that pass only because a mock exists, ensuring your tests verify actual application behavior rather than the configuration of the test doubles themselves.

Can this skill help with production code cleanliness?

Yes, it strictly prohibits adding methods to production classes that are only used for testing, recommending the use of external test utilities instead.

Why does this skill emphasize TDD?

Test-Driven Development naturally prevents most anti-patterns by forcing the developer to see a test fail against real code before introducing any mocks or implementation code.

What are the 'Iron Laws' enforced by this skill?

The Iron Laws are: never test mock behavior, never add test-only methods to production classes, and never mock without understanding dependencies.

How does it handle incomplete mocks?

It enforces a rule to mock complete data structures as they exist in reality, preventing silent failures that occur when downstream code accesses omitted fields.

Testing Anti-Patterns Guard

Name: Testing Anti-Patterns Guard
Author: franroa

byfranroa

0•

セキュリティとテスト

Prevents common software testing mistakes by enforcing best practices for mocks, production code isolation, and test-driven development.

This skill serves as a rigorous guardian for software testing quality, specifically designed to eliminate fragile and misleading test patterns. It enforces 'The Iron Laws' of testing—preventing the verification of mock behavior, stopping the pollution of production code with test-only methods, and ensuring developers fully understand dependencies before mocking. By integrating gate functions into the workflow, it guides Claude to write more resilient, behavior-focused tests that align with strict TDD principles, ultimately improving code maintainability and reducing false-positive test results.

主な機能

010 GitHub stars

02Prevents production code pollution from test-only methods

03Enforces Iron Laws against testing mock behavior

04Validates dependency understanding before mocking

05Ensures complete mock data structures to mirror real APIs

06Promotes Test-Driven Development (TDD) best practices

ユースケース

01Refactoring legacy test suites to reduce brittleness and false positives

02Implementing new features while maintaining strict TDD standards

03Reviewing and improving mock implementations in complex unit tests

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add franroa/chezmoi testing-anti-patterns

For use in Claude.ai and ChatGPT

Download Skill