software-engineering-eng-tdd

What problem does it solve?

This Skill helps you gain testability and confidence in legacy code by identifying seams, writing characterization tests, and applying safe dependency-breaking techniques before refactoring.

Core Features & Use Cases

• Seam finding and classification: Identify object, link, and preprocessing seams to pinpoint where behavior can be altered without changing the risky code in place.
• Characterization-first testing: Capture and lock in current behavior with characterization tests and golden master/approval-style checks for complex outputs.
• Dependency-breaking strategy: Apply pragmatic approaches (e.g., extract-and-override, parameterize constructor, extract interface, sprout/wrap techniques) to break hard dependencies safely.
• Test strategy and anti-pattern avoidance: Use risk-based coverage priorities and avoid brittle or misleading test practices (over-mocking, implementation-detail assertions, slow/flaky tests).

Quick Start

Tell the AI: "Find the seams in my legacy function, propose the smallest dependency-breaking technique to make it testable, and write the first characterization test to lock in current behavior."