Targeted Refactoring Repair Exercises

The required path is P01–P20 and five labs. Use additional reading only for a named weak competency; it is included in the selective reading allocation unless you choose full-book study.

Gap	Local Refactoring topic	Repair evidence
Tests treated as proof	Self-testing code, chunk 032	Boundary and mutation witness
Extraction changes effects	Extract Function, chunk 038	Ordered failure trace
Public rename breaks consumers	Change Function Declaration, chunk 043	Compatible alias and retirement criteria
Eager parsing changes errors	Split Phase, chunk 048	Preserved lookup-before-conversion
Conditional helper evaluates too much	Consolidate Conditional, chunk 067	Lazy call trace with a failing untaken branch

Use the Refactoring book index and reading guide. Return to a fresh practical case after reading.