pharo-refactor

name	pharo-refactor
description	Refactor messy Pharo code safely through the genie MCP tools, working from the live image (no files). Use for renames, method extraction, moving behavior, or general cleanup of existing code.

Pharo refactor loop (live image, via the genie MCP tools)

Refactoring = change structure without changing behavior. The proof that behavior is unchanged is a green test suite before AND after. All reads and writes go through the genie MCP tools; there are no files. Change code only via define_method / define_class / rename_class / remove_method / eval, and read every change back to confirm it.

Loop

1. Green baseline. Run run_test on the relevant class/package. If the code you're about to touch has NO test coverage, STOP and write characterization tests first (use the pharo-tdd skill) — you cannot refactor safely without a safety net.

2. Map impact. Before any rename/move/extract, find every caller and implementor:

   • search_references / search_references_to_class — who uses it
   • search_implementors — who else defines this selector
   • search_methods_like — similar code that may need the same change Make a list. Every item gets updated in this same session.

3. One small change. Make a single structured edit. Read changed methods back with get_method_source.

4. Re-test. Run run_test (class, then package). Green → keep going. Red → the trace shows what broke; fix or revert this one step before moving on. Never batch unverified edits.

5. Repeat steps 3–4 in small increments until the cleanup is complete.

6. Done. Persist with save_image gated on the test package. Summarize the before/after shape.

Common moves

• Rename class: use rename_class — it updates every code reference and symbol literal via the refactoring engine. It does NOT touch string literals, so fix stringly-typed names by hand; and in a test that renames a class, refer to the old name as 'Foo' asSymbol, never #Foo, or the test rewrites its own assertion and self-mangles.
• Remove method: remove_method. Remove class: remove_class.
• Rename method: install the new selector via define_method, repoint every sender (from search_references), then remove_method the old one.
• Extract method: add the new helper, call it from the original, re-test.

Rules

• Behavior-preserving only. If a test changes meaning, that's a feature change — do it under pharo-tdd, not here.
• Small steps, tests between each. A long unverified refactor is a bug factory.
• Modern class API only (ShiftClassInstaller / define_class).