nw-optimize-tests - SKILL.md Agent Skill

name: nw-optimize-tests description: "Minimizes test count while preserving coverage. Detects byte-identical pairs, parametrize-inflation, language-guarantee tests, AST-shape tests, stale migration nets. Approval gate before any change." user-invocable: true argument-hint: '[scope] - Optional: a path (e.g. tests/des/unit/), a feature-id (auto-resolves to tests//), or omit for full unit suite. --reviewer to chain reviewer agent.'

NW-OPTIMIZE-TESTS: Test Suite Optimization

Wave: CROSS_WAVE Agent: Trim (nw-test-optimizer) Reviewer: Trim Review (nw-test-optimizer-reviewer)

Overview

Dispatches Trim to inventory a test scope, detect duplication and anti-patterns, propose a consolidation plan, and apply it after explicit approval. Coverage is preserved; production code is never modified. Use after a feature lands, when a suite feels slow or noisy, on weekly audit, or whenever overtesting is suspected.

Context Files Required

The scope path (passed as argument or auto-detected)
~/.claude/skills/nw-test-optimization/SKILL.md — methodology (loaded by agent)

Timing Baseline

Trim compares against the wall-clock figures recorded in the execution-log.json.

Agent Invocation

@nw-test-optimizer

Execute test optimization for {scope}.

Configuration:

scope: <path | feature-id | empty for full unit suite>
approval_required: true # always; gate is non-negotiable
mutation_validation: false # set true for critical scopes (financial, safety, infra)
reviewer_chain: false # set true to dispatch nw-test-optimizer-reviewer after apply

Approval Gate

Trim presents the plan as a markdown table after Phase 3 (PLAN). The orchestrator (or invoking user) responds with one of:

APPROVE — full plan, all rows
APPROVE WITH EXCLUSIONS — list row IDs to skip
REJECT — abort, return findings as deferred report
REPLAN — provide new scope or constraint

No changes are applied without one of these responses. Trim never assumes approval.

Reviewer Chain (optional)

If reviewer_chain: true:

@nw-test-optimizer-reviewer

Validate the optimization output for {scope}.

Reviewer hard-blocks on: production drift, coverage drop without justification, unmapped removal, missing approval gate evidence.

Success Criteria

Baseline numbers recorded (passed count, coverage %)
Plan presented before any change
Explicit approval received
Production files in diff: 0
Coverage % preserved (or drop documented per skill 5.3)
Atomic commits per consolidation pattern
Final report with deltas and SHAs

Examples

Example 1: Full unit suite audit

/nw-optimize-tests

Trim inventories the unit suite, runs md5sum cross-check, scans for anti-patterns, produces a leverage-sorted plan covering byte-identical pairs and parametrize-inflated files.

Example 2: Scoped to a feature

/nw-optimize-tests lean-wave-documentation

Trim resolves to tests/<feature-id>/ paths from the execution-log.json if available, otherwise scopes to test files referencing the feature-id.

Example 3: Single fat file

/nw-optimize-tests tests/build/unit/test_skill_restructuring.py

Trim probes the single file (315 collected tests), checks migration-collapse lifecycle (skill 3.5), proposes collapse to ~3 tests.

Example 4: With reviewer

/nw-optimize-tests tests/des/unit/ --reviewer

Trim runs the workflow, then dispatches Trim Review for adversarial validation. Reviewer issues YAML verdict.

Out of Scope

Authoring new tests (crafter scope, DELIVER wave)
Production code refactoring (/nw-refactor, crafter scope)
Test infrastructure changes (platform-architect, troubleshooter)

Expected Outputs

git log --oneline {base}..HEAD                  (atomic commits per pattern)
<scope>                                          (test files modified or deleted)
report (returned inline by agent)                (baseline, after, deltas, SHAs)