working-effectively-with-legacy-code
Apply Michael Feathers-inspired legacy-code rules when changing hard-to-test code safely with characterization tests, seams, sprout methods, or wrap methods.
SKILL.md
Working Effectively with Legacy Code Skill
Use this skill when a task involves risky legacy changes, missing tests, characterization tests, seams, dependency breaking, sprout method, wrap method, or incremental risk reduction.
Before making design or code decisions, read and apply working-effectively-with-legacy-code.mini.md. Use working-effectively-with-legacy-code.md only as a deeper reference when the mini rules are not enough for the current legacy-code tradeoff.