TDD

in “Taming AI Coding Agents with TDD.” The first covered test-driven requirements anchoring, the second introduced the GEAR protocol for disambiguation, the third laid out what the tech spec must nail down. This one covers the last line of defense: review. The Problem the Tech Spec Cannot Solve Article 3 ended with an uncomfortable admission. The PRD locks down “what to build.” The tech spec locks down “how to build it.” Together they compress the AI’s improvisation space down to implementation details. That is a huge improvement. ...

in the “Taming AI Coding Agents with TDD” series. The first covered test-driven requirements anchoring, the second covered the GEAR protocol for requirements disambiguation. This one fills the gap between them: after the PRD is done, what must the tech spec cover? Requirements Locked, Code Still Wrong Before the second Aristotle refactor, I spent two full days writing requirements. Following the structured approach from the previous article, I captured every acceptance criterion, boundary condition, error path, and platform constraint[1]. The AI consumed the document, passed all 37 static assertions plus end-to-end tests. The codebase was split into four files by responsibility. Information flow was switched from push to pull. ...

This is the first article in the series “Taming AI Coding Agents with TDD.” The series has one thesis: AI-assisted development demands stricter process discipline than traditional development, and here is exactly how to enforce it at every step. The series follows the pipeline order — requirements, design, testing, review, implementation. This article starts at the testing layer. During Aristotle’s third refactoring, the test plan document was where I learned the hardest lesson. I’ll cover this layer first, then work backward and forward in subsequent posts. ...