Mastermind Verify

MasterMind — Verify

Proving a change works is never optional — but that doesn't mean writing tests. This is the disciplined way to QA a feature by driving the real thing and watching what it does. Writing automated tests / adopting TDD is a project choice — ask first (~/.mastermind/engineering/core/rigor.md); verifying that it works is not. "Looks right" is not verification.

The loop

1. Define "works." Restate the expected behavior and the acceptance criteria — what the user asked

for, in observable terms. If you can't say what correct looks like, you can't verify it.

1. Pick the lightest real check. Prefer driving the actual thing over reasoning about it: run the

app and click the flow, hit the endpoint, run the script/CLI, render the component. Reuse the project's run/dev command; don't build harness the project doesn't have.

1. Exercise the happy path — then the edges that matter. Walk the intended flow, then the cases

rigor.md names: empty, null, error, loading, zero/one/many, unauthorized, malformed input, offline/ slow. Observe actual output and state, not what the code "should" do.

1. Check the invisible. Typecheck, lint, and build. Watch the console/network for errors and

warnings. For UI: keyboard + focus, contrast, and no layout shift/regression in nearby areas.

1. Report with evidence. Show what you ran and what you observed (command output, the response, a

screenshot). State confidence plainly. If you couldn't run a check (no environment), say so and fall back to the most rigorous manual trace available — never present unrun work as verified.

Rules

• Don't add tests, a test framework, or TDD to a project that has none unprompted — offer them as a

suggestion instead. Where the project does test, run its suite as part of step 2–4.

• Verify against the requirement, not the implementation you just wrote — a hostile reviewer's eye.
• Found a bug? Fix the root cause (or route to mastermind-debug if it's not obvious) — never

suppress a symptom to make the check pass.

Output

A plain verdict — works / doesn't, with the evidence — the edge cases exercised, and any gaps you couldn't cover (with why). If the user wants this locked in permanently, offer mastermind-tdd.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: mehrad-dm
• Source: mehrad-dm/mastermind
• License: MIT
• Homepage: https://mastermind.mehrad.me

Install and usage instructions live in the source repository linked above.