How to use ts-check/jsdoc with javascript ava?

[sombriks]

i know that there is type definitions but no luck on how to proper import it.

any guidance is welcome.

[manimovassagh]

You can get type checking with JSDoc in AVA test files. The key is importing AVA's types via JSDoc annotations.

1. Set up jsconfig.json (or tsconfig.json with allowJs)

{
  "compilerOptions": {
    "checkJs": true,
    "strict": true,
    "module": "ESNext",
    "moduleResolution": "node",
    "target": "ESNext"
  },
  "include": ["**/*.js"]
}

2. In your test files, use JSDoc type imports

import test from 'ava';

test('my test', (/** @type {import('ava').ExecutionContext} */ t) => {
  // t.is(), t.deepEqual(), etc. all have autocomplete now
  t.is(1 + 1, 2);
});

3. For typed context (like fixtures, beforeEach hooks)

import anyTest from 'ava';

/** @type {import('ava').TestFn<{server: import('http').Server}>} */
const test = /** @type {any} */ (anyTest);

test.before((t) => {
  // t.context.server is typed here
});

test('uses server', (t) => {
  t.truthy(t.context.server);
});

The cast through any is needed when narrowing the generic type since JSDoc can't express generic function calls the way TypeScript can. But after the cast, you get full autocomplete and type checking on t and t.context.