Refactor

Refactor

Execute a structural method inside an authorised implement run. This skill inherits exact paths, non-goals and repair limits; it cannot widen scope, accept the change, release it or turn nearby cleanup into work.

Entry evidence

Before editing, record:

• the named cost/risk to remove and the observable behaviours that must not change;
• public API, schema, protocol, data, ordering, error and performance invariants;
• a green baseline plus characterisation, differential, replay, property or compatibility checks selected by risk;
• the dependency cone: callers, exports, registration/configuration, generated artifacts, persistence and mixed-version boundaries;
• canonical ownership, duplicate/parallel paths, rollback seam and a move/deletion manifest.

Use SOLID and related principles as probes, not success metrics: improve cohesion and single ownership; preserve substitutability and caller contracts; segregate interfaces only where clients carry unused coupling; invert volatile dependencies only when the new seam hides real complexity. Prefer simple, explicit state and information hiding over speculative abstraction, pattern count, DRY-by-text or acronym compliance.

If the desired structure or behaviour is undecided, route to scope. If a failure's cause is unknown, use diagnose. Changed behaviour is a separate TDD slice, never hidden in the refactor.

Method

1. Establish a seam while green. Do not start by deleting the old path.
2. Move one independently reviewable responsibility at a time. Preserve the public contract or use an approved compatibility adapter with an expiry.
3. Switch callers/registrations to one canonical owner and verify after each slice. Keep focused checks fast; run affected and full required gates at the enclosing tranche.
4. Delete only when caller, runtime, build, registry, reflection/dynamic-load, configuration and data evidence show the path is unreachable or replaced. Unknown, user-owned and unrelated files stay untouched.
5. Stop on behaviour drift, unexplained performance/resource change, scope expansion or an invariant the evidence cannot cover. Revert only exact run-owned hunks under authority and return to scope/diagnose as needed.

Completion gate

Provide before/after ownership and dependency deltas, the classified move/deletion manifest, exact verification results and residual risk. Pass only when observable/API/schema/data contracts remain equivalent, the named structural debt is measurably reduced, no unowned parallel path remains, relevant performance/resource budgets hold, documentation is current and an independent code-review finds no blocking regression. Lines deleted alone are never proof.