review-testability

To audit code for testability, you review the source to locate patterns mixing business logic with IO, hidden dependencies, and hard-coded instantiation. This surfaces testability friction while preserving a read-only constraint on the source.

Common testability anti-patterns include implicit dependencies, global state, and constructor work. These patterns tie business logic to IO operations, making code difficult to test and maintain without structural refactoring.

Refactor code to separate business logic from IO by applying patterns like functional core and imperative shell. This design isolates pure logic from side effects, enabling safer unit testing and more maintainable code structures.

Yes, you can scope a code review by specifying target file paths or providing a diff against origin/main. This targets relevant changes and contexts, ensuring the testability analysis focuses only on the specified code modifications.

Dependency injection improves testability by making dependencies explicit rather than hidden or hard-coded. This allows you to inject mock implementations during unit testing, isolating business logic from external IO operations and global state.