testing-anti-patterns

Testing anti-patterns are ineffective practices like over-mocking, fragile tests, and test-only production code that reduce test reliability. Analyze your test suite for signs: tests that break on refactoring, mocks substituting for real behavior validation, or methods added solely to support testing. This skill identifies these patterns and suggests refactoring strategies to improve test quality.

Testing real behavior validates actual system logic; testing mock behavior only verifies the mock itself, providing false confidence. Anti-patterns occur when mocks shield you from catching production bugs. This skill enforces the rule of never testing mock behavior, ensuring your tests catch real failures by mocking dependencies while validating genuine code paths.

Slow, flaky tests often result from anti-patterns like mocking everything, iceberg tests with hidden dependencies, or unclear test-to-production boundaries. This skill analyzes test suites to identify these pitfalls and provides correction strategies, helping you refactor for speed and reliability.

No. Adding test-only production methods is an anti-pattern that violates production code purity and creates maintenance debt. This skill enforces the rule that production code must remain independent of test requirements, recommending design refactoring instead of test-specific hooks.

Mocking is appropriate when you isolate a component to test its logic without external side effects. However, anti-patterns emerge when you mock without understanding dependencies or mock production boundaries incorrectly. This skill provides gate checks and explicit examples to ensure mocks target the right scope and validate real behavior.

Yes. This skill addresses testing anti-patterns across unit and integration test frameworks regardless of language. It focuses on universal principles—mock usage, test fragility, and production boundaries—applicable to any codebase, with examples demonstrating patterns and corrections.