Does this skill work with Test-Driven Development (TDD)?

Yes, it is highly complementary to TDD by ensuring that as you write tests first, you avoid common traps like incomplete mocks or unnecessary dependencies.

How does this skill improve my test suite?

It enforces testing real behavior instead of mock implementations, which makes tests less brittle and ensures they actually catch regressions in logic.

Why is mocking considered an anti-pattern here?

Mocking itself isn't the problem, but testing 'mock existence' or mocking without understanding side effects is. This skill helps you mock at the correct level to ensure your test remains valid.

How can I tell if my mock is 'incomplete'?

The skill checks if your mocks are missing metadata or fields that downstream code uses, preventing tests from passing on objects that would fail in a real environment.

What are 'test-only' methods in production?

These are methods added to production classes solely to facilitate testing. This skill helps you identify them and move them to dedicated test utilities to keep production code clean.

Testing Anti-Pattern Guard

Name: Testing Anti-Pattern Guard
Author: timequity

bytimequity

0•

Security & Testing

Prevents common testing pitfalls like mocking behavior over reality and polluting production code with test-only methods.

The Testing Anti-Patterns skill serves as a high-integrity guardian for your test suite, ensuring that unit and integration tests focus on real behavior rather than implementation details. It enforces strict 'Iron Laws' to prevent the testing of mocks, identifies production code pollution caused by test-only methods, and warns against incomplete mocks that lead to false positives. By integrating this skill, developers can maintain a clean separation between production and test logic while ensuring their test coverage accurately reflects the system's actual functionality, ultimately leading to more resilient and maintainable codebases.

Key Features

01Detects test-only methods that leak into production classes and suggests cleaner utility alternatives

02Identifies and prevents the testing of mock behavior rather than actual code logic

030 GitHub stars

04Flags red flags like bloated mock setups and inappropriate test-specific IDs in production code

05Ensures mock objects completely mirror real API structures to avoid brittle or misleading test results

06Provides gate functions to evaluate the necessity and side effects of dependencies before mocking

Use Cases

01Refactoring legacy test suites to remove brittle mocks and improve reliability

02Auditing production code for 'test-only' method pollution before deployment

03Guiding developers during TDD to ensure tests verify outcomes rather than implementation details

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add timequity/plugins testing-anti-patterns

For use in Claude.ai and ChatGPT

Download Skill