simplify

Purpose

Runs at pipeline batch boundaries. Catches accumulated duplication, complexity, and over-engineering before they compound across batches. Enforces "dry business logic, not dry code" — extract shared behavior, not shared shape.

This is NOT a full codebase audit. It is scoped to the current batch's changes, except that changed tests must be compared with existing tests at the same production seam.

Practices

1. Scope Detection

Identify files changed in the current batch:

git diff <batch-start-commit>..HEAD --name-only

Keep non-test analysis limited to these files. For each changed or added test, additionally inspect existing tests at the same production seam; do not scan unrelated code or tests. The batch-start commit is available from .pipeline/audit-trail/batch-N/ or from the pipeline's progress log.

2. Duplication Check

Look for duplicated business logic across batch-changed files. Distinguish between:

Type	Example	Action
Duplicated behavior	Same validation logic in two services	Must extract
Duplicated shape	Two serializers with similar structure	Leave alone
Copy-paste with tweaks	Same method with 1-2 param differences	Extract with parameters — except a declared replication's exact mapped source/target pair alone is not an extract-with-parameters finding. Still flag undeclared duplication or similarity outside the declared target set; with no declaration, apply this row unchanged. A declared pair may retain an extraction finding when rationale beyond the declared replication merits it.

Flag when 3+ similar blocks exist across different files. Two similar blocks in the same file are a judgment call — flag only if the logic is non-trivial.

Before recommending extraction, inlining, or a competing abstraction, consult the applicable focused pattern basis (for example, the approved plan, architecture decision, or declared replication contract). Flag only a material, unapproved departure from that basis. Accept a variation the basis allows, a verified case where the proposed extraction does not fit the accepted design, or a departure that the operator or accepted artifact explicitly authorizes. This alignment check does not turn shared shape into shared behavior: extract only shared business behavior.