Fairy Fox

Updates · · random-ai-promptupdate

Random AI Prompt: a full test suite, and back to shipping

Vitest and Playwright land, then a long-stalled CI pipeline is unbroken so the stable branch can move again.

Random AI Prompt closed out its revival sprint with the two things a modernised project needs most: real tests and a working release path.

From a smoke test to a real suite

Until now the project had only linting and an import smoke test. It now has layered coverage — Vitest for the Node engine and the React app, Playwright for the browser:

$ npm test
✓ lint (0 errors)
✓ smoke (module graph + all prompts)
✓ vitest  — 88 node + 30 web   (118 passed)

$ npm run test:e2e
✓ playwright — e2e + visual + a11y   (8 passed)

The browser specs include visual-regression snapshots (with the random suggestion masked so the page is stable) and accessibility checks via @axe-core/playwright.

The landmine worth documenting

The most instructive detail: the underlying utility library captures the global random function at import time, so you can’t make its randomness deterministic by overriding Math.random in a test:

// Does NOT work — lodash already captured Math.random on import
Math.random = () => 0.42;
expect(_.sample(list)).toBe(list[0]);   // still random

// What the tests do instead: assert invariants, not exact picks
const out = expandPrompt("{#city}");
expect(out).toMatch(/streetview/);          // structure is stable
expect(out.split(",").length).toBeGreaterThan(2);

Only the language’s own renderer, which uses its own seeded RNG, is driven deterministically. (Getting the browser tests to launch on the dev machine was its own saga, ultimately solved by pointing Playwright at the system Chrome.)

Unbreaking the pipeline

With tests in place, the focus turned to shipping. The stable branch had been held at the pre-revival state, and recent commits were red in CI — not from test failures, but from the install step:

npm error code EUSAGE
npm error `npm ci` can only install with an up to date package-lock.json
npm error Missing: @emnapi/core@1.11.1 from lock file

The lockfile had drifted after the new dependencies came in, and an incremental npm install on the Windows machine omitted the Linux-only optional packages that CI needs. The fix that actually works is a clean, full resolve so every platform’s optional dependencies are recorded:

rm -rf node_modules package-lock.json
npm install        # fresh resolve records @emnapi/*, linux-* bindings, etc.
npm ci             # now passes the sync check

Once green, the stable branch fast-forwarded to the current work for the first time in the revival — which promptly exposed two more first-time deployment breakages in the docs and release workflows, both fixed. A recurring theme of the week held to the end: the failures were almost never the code itself, but the build, packaging, and tooling around it.

References

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