How do I write a test?

  • Note: Every generated app's package.json gets an "imports": { "#root/*.js": "./*.js" } entry, so test files can write import { foo } from '#root/path/to/foo.js'.

File discovery

Files matching *.test.js, anywhere under a configured origin directory, are discovered automatically (see How do I configure testin-nutin?).

Global API

Installed before any test file loads:

describe('globals beforeEach/All and afterEach/All', () => {
  // `beforeEach/All` and `afterEach/All` must be INSIDE a `describe` block
  beforeAll(() => { beforeAllCount++; });
  beforeEach(() => { beforeEachCount++; });
  afterEach(() => { afterEachCount++; });
  afterAll(() => { console.debug('afterAll called.'); });

  it('should be called once for all and once for each', () => {
    expect(beforeAllCount).toEqual(1);
    expect(beforeEachCount).toEqual(1);
    expect(afterEachCount).toEqual(0);
  });
  it.todo('Keep counting.');
});
  • describe(name, fn) / it(name, fn) — no test() alias, only it.
  • beforeAll / beforeEach / afterEach / afterAll — one hook of each kind per suite; declaring a second one in the same describe silently overwrites the first (no stacking/composition).
  • DOM helpers: $(selector) / $(selector) (querySelector/ querySelectorAll shorthands), click(el), type(el, text).
  • setupJsdom / teardownJsdom / resetDom / flushPromises / silenceConsole are also exposed as globals if a test needs to manage the DOM environment directly.

See What assertions are available?.