Individual skill
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.
skills-imported/working-effectively-with-legacy-code/SKILL.md
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- Last checked
- Nov 8, 2026
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- Repository last updated
- Oct 10, 2026
- License
- MIT
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SKILL.mdcore · 803 bytesreferences/working-effectively-with-legacy-code.mddoc · 13,817 bytesreferences/working-effectively-with-legacy-code.mini.mddoc · 5,707 bytesreferences/working-effectively-with-legacy-code.nano.mddoc · 1,792 bytes
Read excerpt
# 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](working-effectively-with-legacy-code.mini.md). Use [working-effectively-with-legacy-code.md](working-effectively-with-legacy-code.md) only as a deeper reference when the mini rules are not enough for the current legacy-code tradeoff.