Pharo Rename Method

Use this skill only for behavior-preserving selector renames in a live Genie image. Work through the genie MCP tools; do not edit Tonel files.

Workflow

1. Establish a green baseline with run_test for the narrow class or package you will touch.

2. Map the impact before renaming:

   • search_implementors for the old selector.
   • search_references for the old selector.
   • get_method_source for representative implementors and callers.

3. Use rename_method, not define_method plus remove_method, when the intent is a real rename:

   • class_name: owning class name, without class.
   • method_name: old selector string.
   • new_method_name: new selector string.
   • is_class_method: true for class-side methods, omit or false for instance-side methods.
   • permutation: optional argument-position array, for example [2, 1]. Omit it for ordinary same-order renames.

4. Read back the changed methods. Confirm:

   • The old selector is gone from the intended class.
   • The new selector exists.
   • Senders now use the new selector.
   • Any symbol-literal references that should change have changed.

5. Rerun the same tests. If the rename is part of a larger refactoring, stop at the first green rename before making the next structural move.

6. Save the image only through save_image gated on the relevant test class or package.

Sequencing

Use rename-method early when an unclear selector is hiding the next move. For example:

• Rename a misleading public message before extracting a helper that will call it.
• Rename a collaborator-facing selector before moving behavior to that collaborator.
• Rename a protocol family one selector at a time, testing between each rename.
• Rename test fixture selectors with care: refactoring updates symbol literals. In tests that assert the old selector disappeared, write 'oldSelector' asSymbol, not #oldSelector, or the refactoring may rewrite the assertion itself.

Do not use rename_method to change arity and behavior together. First make behavior-preserving same-arity renames green. Then do signature or behavior changes under a test-first workflow.

Example

{
  "class_name": "Invoice",
  "method_name": "total",
  "new_method_name": "totalAmount"
}