Unit Testing Utility Classes and Static Methods Overview This skill generates tests for utility classes with static helper methods and pure functions. It provides patterns for testing null handling, edge cases, boundary conditions, and common utilities like string manipulation, calculations, data validation, and collections. Pure functions require no mocking. When to Use Use this skill when: - Writing tests for utility/helper classes with static methods - Testing pure functions with no state or side effects - Testing string manipulation, formatting, or transformation utilities - Testing calcu…