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171 changes: 171 additions & 0 deletions recipes/mocha-to-node-test-runner/README.md
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# Mocha to Node.js Test Runner

This recipe migrate Mocha v8 tests to Node.js test runner (v22, v24+)
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Suggested change
This recipe migrate Mocha v8 tests to Node.js test runner (v22, v24+)
This migrates Mocha 8.x tests to Node.js (22.x, 24.x) test runner


## Features

- Automatically adds `node:test` imports/requires
- Converts global `describe`, `it`, and hooks to imported versions
- Transforms `done` callbacks to `(t, done)` signature
- Converts `this.skip()` to `t.skip()`
- Converts `this.timeout(N)` to `{ timeout: N }` options
- Preserves function styles (doesn't convert between `function()` and arrow functions)
- Supports both CommonJS and ESM

## Examples

### Example 1: Basic

```diff
```
const assert = require('assert');
+const { describe, it } = require('node:test');

describe('Array', function() {
describe.skip('#indexOf()', function() {
it('should return -1 when the value is not present', function() {
const arr = [1, 2, 3];
assert.strictEqual(arr.indexOf(4), -1);
});
});
});
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nit: spaces (instead of tabs) please in markdown codeblocks because most viewers render tabs enormous 😭

```

### Example 2: Async

```diff
```
const assert = require('assert');
+const { describe, it } = require('node:test');
describe('Async Test', function() {
- it('should complete after a delay', async function(done) {
+ it('should complete after a delay', async function(t, done) {
const result = await new Promise(resolve => setTimeout(() => resolve(42), 100));
assert.strictEqual(result, 42);
});
});
```

### Example 3: Hooks

```diff
```
const assert = require('assert');
const fs = require('fs');
+const { describe, before, after, it } = require('node:test');
describe('File System', () => {
before(function() {
fs.writeFileSync('test.txt', 'Hello, World!');
});

after(() => {
fs.unlinkSync('test.txt');
});

it('should read the file', () => {
const content = fs.readFileSync('test.txt', 'utf8');
assert.strictEqual(content, 'Hello, World!');
});
});
```

### Example 4: Done

```diff
```
const assert = require('assert');
+const { describe, it } = require('node:test');
describe('Callback Test', function() {
- it('should call done when complete', function(done) {
+ it('should call done when complete', function(t, done) {
setTimeout(() => {
assert.strictEqual(1 + 1, 2);
done();
}, 100);
});
})
```

### Example 5: Skipped

```diff
```
const assert = require('assert');
+const { describe, it } = require('node:test');
describe('Skipped Test', () => {
it.skip('should not run this test', () => {
assert.strictEqual(1 + 1, 3);
});
- it('should also be skipped', () => {
- this.skip();
+ it('should also be skipped', (t) => {
+ t.skip();
assert.strictEqual(1 + 1, 3);
});

- it('should also be skipped 2', (done) => {
- this.skip();
+ it('should also be skipped 2', (t, done) => {
+ t.skip();
assert.strictEqual(1 + 1, 3);
});

- it('should also be skipped 3', x => {
- this.skip();
+ it('should also be skipped 3', (t, x) => {
+ t.skip();
assert.strictEqual(1 + 1, 3);
});
})
```

### Example 6: Dynamic

```diff
```
const assert = require('assert');
+const { describe, it } = require('node:test');
describe('Dynamic Tests', () => {
const tests = [1, 2, 3];

tests.forEach((test) => {
it(`should handle test ${test}`, () => {
assert.strictEqual(test % 2, 0);
});
});
});
```

### Example 7: Timeouts

```diff
const assert = require('assert');
-describe('Timeout Test', function() {
- this.timeout(500);
+const { describe, it } = require('node:test');
+describe('Timeout Test', { timeout: 500 }, function() {
+
+
+ it('should complete within 100ms', { timeout: 100 }, (t, done) => {

- it('should complete within 100ms', (done) => {
- this.timeout(100);
setTimeout(done, 500); // This will fail
});

- it('should complete within 200ms', function(done) {
- this.timeout(200);
+ it('should complete within 200ms', { timeout: 200 }, function(t, done) {
+
setTimeout(done, 100); // This will pass
});
});
```

## Caveats

* `node:test` doesn't support the `retry` option that Mocha has, so any tests using that will need to be handled separately.

## References
- [Node Test Runner](https://nodejs.org/api/test.html)
- [Mocha](https://mochajs.org/)
26 changes: 26 additions & 0 deletions recipes/mocha-to-node-test-runner/codemod.yaml
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schema_version: "1.0"
name: "@nodejs/mocha-to-node-test-runner"
version: 1.0.0
capabilities:
- fs
- child_process
description: Migrate Mocha v8 tests to Node.js test runner (v22, v24+)
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Suggested change
description: Migrate Mocha v8 tests to Node.js test runner (v22, v24+)
description: Migrate Mocha 8.x tests to Node.js (22.x, 24.x) test runner

author: Xavier Stouder
license: MIT
workflow: workflow.yaml
category: migration

targets:
languages:
- javascript
- typescript

keywords:
- transformation
- migration
- mocha
- test

registry:
access: public
visibility: public
24 changes: 24 additions & 0 deletions recipes/mocha-to-node-test-runner/package.json
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{
"name": "@nodejs/mocha-to-node-test-runner",
"version": "1.0.0",
"description": "Migrate Mocha v8 tests to Node.js test runner (v22, v24+)",
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Suggested change
"description": "Migrate Mocha v8 tests to Node.js test runner (v22, v24+)",
"description": "Migrate Mocha 8.x tests to Node.js (22.x, 24.x) test runner",

"type": "module",
"scripts": {
"test": "npx codemod jssg test -l typescript ./src/workflow.ts ./"
},
"repository": {
"type": "git",
"url": "git+https://github.com/nodejs/userland-migrations.git",
"directory": "recipes/mocha-to-node-test-runner",
"bugs": "https://github.com/nodejs/userland-migrations/issues"
},
"author": "Richie McColl",
"license": "MIT",
"homepage": "https://github.com/nodejs/userland-migrations/blob/main/recipes/mocha-to-node-test-runner/README.md",
"devDependencies": {
"@codemod.com/jssg-types": "^1.3.1"
},
"dependencies": {
"@nodejs/codemod-utils": "*"
}
}
13 changes: 13 additions & 0 deletions recipes/mocha-to-node-test-runner/src/remove-dependencies.ts
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import type { Transform } from '@codemod.com/jssg-types/main';
import type Json from '@codemod.com/jssg-types/langs/json';
import removeDependencies from '@nodejs/codemod-utils/remove-dependencies';

const transform: Transform<Json> = async (root) => {
return removeDependencies(['mocha', '@types/mocha'], {
packageJsonPath: root.filename(),
runInstall: false,
persistFileWrite: false,
});
};

export default transform;
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