Refactor (Behavior-Preserving)

Goal

Improve internal structure without changing observable behavior.

Observable behavior includes outputs, side effects, performance envelopes, error shapes, logging/metrics contracts, and public API compatibility.

Guardrails

• Preserve semantics first; readability second.
• Keep changes small and mechanical; verify after each step.
• Do not mix refactors with feature changes in the same diff.
• Prefer compiler/typechecker + tests as the safety net.

If the code has no tests, start by adding characterization tests around the current behavior (including edge cases and error paths).

Workflow