/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."
argument-hint: '[scope] - Optional: a path (e.g. tests/des/unit/), a feature-id (auto-resolves to tests/<id>/), 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)
• `nWave/skills/nw-test-optimization/SKILL.md` — methodology (loaded by agent)

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:

1. **APPROVE** — full plan, all rows 2. **APPROVE WITH EXCLUSIONS** — list row IDs to skip 3. **REJECT** — abort, return findings as deferred report 4. **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 execution-log.json if available, otherwise scopes to test files referencing the feature-id. Plan focuses on intra-feature duplication.

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)