Mocha — Simple, flexible and fun testing framework for JavaScript

Mocha - the fun, simple, flexible JavaScript test framework

Here’s a simple example of a Mocha test:

Install Mocha

$ npm install mocha
$ mkdir test
$ $EDITOR test/test.js # or open with your favorite editor

Write your test

const assert = require('assert');

describe('Array', function() {
describe('#indexOf()', function() {
it('should return -1 when the value is not present', function() {
assert.equal([1, 2, 3].indexOf(4), -1);
});
});
});

Set up a test script in package.json

"scripts": {
  "test": "mocha"
}

Run you test

$ npm test

In this example, we’re testing the `indexOf` method of an array to ensure it returns -1 when the value is not present.

To use Mocha, you typically install it via npm (Node Package Manager) and then run your test files using the `mocha` command. Mocha is often used in combination with assertion libraries like Node.js’s built-in `assert` module, or third-party libraries like Chai.

Thanks;)