Tdd

Here's a structured approach to Test-Driven Development with 42 rules across 8 categories, from critical (red-green-refactor cycle) to low priority (test pyramid strategy). Each rule gets a prefix like cycle-, design-, or isolate-, making it easy to reference specific practices. The guide walks through the full TDD workflow and includes quick references for things like the AAA pattern, test isolation, and data management. It's built for AI agents but reads like a solid developer reference. One honest take: the categorization and priority system actually makes this more useful than most TDD guides that just throw all the rules at you at once. Goes well with the separate vitest and msw skills for framework specifics.