How do I use Chai with Mocha for testing?

How do I use Chai with Mocha for testing?

To use Chai with Mocha, first install both libraries using npm. You can run npm install mocha chai.

What are some basic assertions I can use with Chai?

Chai provides several assertion styles. For example, you can use expect, should, or assert. A basic example is expect(value).to.equal(expectedValue);.

Can you show me a simple test example?

Sure! Here's a simple test:

const chai = require('chai');
const expect = chai.expect;

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