test-matrix

name	test-matrix
description	Use when a project needs testing BEYOND unit tests — fuzzing, property-based, load, E2E, or mutation. Five-phase hub-and-spoke pipeline composes the right mix per language × critical path × CI target, scaffolds configs + corpus + fixtures, wires CI jobs, and defines the crash/regression triage workflow. Pure-click: every decision except intake is an AskUserQuestion.
argument-hint	<free-text description of what needs testing and why>

/test-matrix — Testing beyond unit tests (index)

When to use

• A project needs testing beyond unit tests: fuzzing, property-based, load, E2E, or mutation testing.
• At project kickoff or when coverage gaps span multiple test paradigms across the stack.
• Use /test-matrix for project-wide strategy; use /test-gen for per-function unit tests.

You are designing a testing matrix for a project that already has (or should have) unit-test coverage via /test-gen. This skill owns the orthogonal axes:

• Fuzzing — input-space exploration at boundaries (parsers, deserializers, crypto)
• Property-based — invariants verified over generated inputs (pure functions, data structures)
• Load — SLO assertion under traffic (k6/vegeta/oha, baseline→profile→fix)
• E2E — browser-driven critical journeys (Playwright, page objects, trace viewer)
• Mutation — test-suite quality verification (mutmut / cargo-mutants / StrykerJS)

Not duplicated here: happy-path / edge / error unit tests (/test-gen owns those). This skill links rather than re-implements.

This SKILL.md is the INDEX. Each phase lives in its own file, executed in order. Never skip, never re-order.

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Pipeline overview (5 phases + final report)

Phase	File	Purpose	AskUserQuestion count
1	phase-1-intake.md	Language(s), coverage baseline, critical paths, CI target	1× (multi-part)
2	phase-2-matrix.md	Select test types × languages matrix	1× multi-select
3	phase-3-scaffold.md	Generate config + corpus + fixtures per selected cell	1× per cell
4	phase-4-ci-wire.md	CI job per test type; artifacts; failure policy	1× multi-select
5	phase-5-triage.md	Crash + regression triage workflow	1×

Minimum AskUserQuestion count across a full session: 5 (one per phase). Higher when Phase 3 expands per selected cell. This is the pure-click contract.

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Variables the pipeline produces

Name	Set in	Meaning
LANGS	Phase 1	Languages in scope (Rust / Python / JS-TS / Go / Swift / Flutter — multi)
COVERAGE	Phase 1	Baseline unit-test coverage % (or "unknown")
CRITICAL	Phase 1	Critical paths: auth / payment / data-integrity / perf / untrusted-input
CI	Phase 1	github-actions / forgejo-actions / self-hosted / none
MATRIX	Phase 2	Set of (test-type × language) cells to scaffold
SCAFFOLDED	Phase 3	Files written per cell (paths + corpus seeds)
CI_JOBS	Phase 4	CI workflow entries added per cell
TRIAGE_DOC	Phase 5	Path to docs/testing/triage.md (or project-local equivalent)

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Final report (emit after Phase 5)

=== TEST-MATRIX REPORT ===
Languages:        <LANGS>
Coverage (unit):  <COVERAGE>
Critical paths:   <CRITICAL>
Matrix cells:     <count> — <list (type × lang)>
Files written:    <count> (configs + corpus + fixtures)
CI jobs added:    <count> (<per-type failure policy>)
Triage doc:       <TRIAGE_DOC>
Next action:      Run <cmd> locally to verify the scaffold, then commit.

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Rules (apply throughout)

• Pure-click contract. Only the Phase 1 intake paragraph is free text. Everything else is AskUserQuestion. Count in the final report.
• NO DOWNGRADE (RULE -1). If a language × type cell has no good tool, return 2-3 constructive paths, never "not supported".
• NO HALLUCINATION (RULE 0.4). Every tool / library cited must exist and be current. When in doubt, mark [UNVERIFIED — verify release page] and surface in the report.
• Plan Mode First (RULE 0.5). This skill IS the plan; no writes before the corresponding phase's confirm click.
• Constructor Pattern (RULE ZERO). Block files (_blocks/test-*.md) stay ≤ 60 LOC. This SKILL.md ≤ 200 LOC; phase files ≤ 150 LOC each.
• Surgical Changes. Writes only to:
  • <repo>/tests/, <repo>/fuzz/, <repo>/e2e/, <repo>/load/
  • <repo>/.github/workflows/ or <repo>/.forgejo/workflows/
  • <repo>/docs/testing/triage.md
  • No writes to _blocks/ here (that's compose-solution's Phase 6).
• No duplication with /test-gen. If the user really wants unit-test generation, Phase 1 detects it and hands off immediately.

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References

• phase-1-intake.md · phase-2-matrix.md · phase-3-scaffold.md · phase-4-ci-wire.md · phase-5-triage.md
• skills/test-gen/SKILL.md — unit-test generation (happy / edge / error). Phase 1 hands off there if intake reveals unit-test gap, not matrix gap.
• _blocks/test-fuzz.md · _blocks/test-property.md · _blocks/test-load.md · _blocks/test-e2e.md — per-paradigm reference blocks, composable into manifests.
• _blocks/rule-test-first.md — TDD / tests-with-code discipline (inherited).
• skills/compose-solution/SKILL.md — if you need a NEW block (e.g. mutation-specific), hand off there (Phase 6 block-augment).