piggy-test

name	piggy-test
description	Generate the smallest runnable test that would fail if the lazy solution broke — one check, no framework or fixtures unless the repo already uses one. Use when the user says "test this", "piggy test", "/piggy-test", or "write a check for this".

Piggy Test

Write the smallest test that fails if the lazy solution breaks. This mirrors the README's rule that non-trivial logic leaves one runnable check behind — this skill is that check, on demand.

Rules

• One test per behavior, not a suite. Cover the happy path and the one edge case that would actually bite (empty input, boundary value, the thing the ticket was about) — not every theoretical edge case.
• Use whatever the repo already uses (assert, the installed test runner). Don't introduce a new test framework or fixture library for one check.
• Trivial one-liners (a stdlib call, a native feature) need no test — say so and stop rather than manufacture one.
• No mocks, no setup/teardown scaffolding, unless the function under test genuinely can't run without them.

Output

## Test
<the minimal runnable check>

## Covers
<one line: what breaking would look like if this failed>

Example

// piggy: assumes one @, no RFC 5322 edge cases
const isValidEmail = (s) => /\S+@\S+\.\S+/.test(s);

## Test
console.assert(isValidEmail('[e-mail]') === true, 'valid email rejected');
console.assert(isValidEmail('not-an-email') === false, 'invalid email accepted');

## Covers
regex stops matching real addresses, or starts matching garbage.

Boundaries

One check, not coverage. For a fuller suite the user should say so explicitly — this skill's default is the minimum, not the maximum. "stop piggy-test" or "normal mode" to revert.