refactoring-recipeslisted

Refactor safely by name: a catalogue of the refactorings that come up in practice (extract function or module, inline, rename, replace conditional with polymorphism or lookup, introduce parameter object, replace flag argument, split phase, move function, encapsulate collection, strangler for large rewrites), each with when to apply it, the mechanical steps that keep the code working at every step, and the test to run between steps. Use when code is hard to change, before adding a feature to a tangled area, or when a reviewer asks for a structure change without saying how.
KhaledSaeed18/dotclaude · ★ 5 · Code & Development · score 80

Install: claude install-skill KhaledSaeed18/dotclaude

A refactoring changes structure without changing behaviour, in steps small enough that the tests pass after each one. If you cannot run tests between steps, the first refactoring is to make the code testable. If you are changing behaviour, that is a feature or a fix; do not mix it with refactoring in the same commit. ## Before any refactoring 1. **Tests exist and pass.** Characterisation tests for legacy code: capture current outputs for representative inputs before touching anything. 2. **Scope is named.** The smell you are removing and the boundary you will not cross. 3. **Commit is clean.** Refactor on its own commit(s) so a reviewer can verify "no behaviour change" by reading the diff. ## Recipes **Extract function.** When a block does one nameable thing inside a longer function, or the same block appears twice. Steps: name the function after what it does; copy the block; identify inputs (parameters) and outputs (return); replace the block with a call; run tests. Watch for variables assigned in the block and read after it (return them, or split the extraction). **Inline function.** When a function's body is as clear as its name and it has one caller, or the indirection hides what happens. Steps: check it is not overridden; replace each call with the body; remove the function; run tests. **Rename.** When a name lies or is vague. Steps: use the IDE or language-server rename for symbols; for strings and config keys, grep all occurrences including docs and tests; rename