Typescript boilerplate test configuration with mocha, chai and sinon

#typescript #testing #tutorial #javascript

Hi, Devs!

Let's configure tests with mocha, chai and sinon on Typescript in a few steps.

Lets' start the project:

npm init -y

Now, let's install the packages. Here we also install the types (@types) of each library because we need to use them on Typescript. Usually we need to test some elements that returns one promise, so we need do install chai-as-promised.

npm i -D mocha @types/mocha chai @types/chai 
npm i -D sinon @types/sinon
npm i -D chai-as-promised @types/chai-as-promised

We need to use ts-node library to run our tests, because using Typescript we have to transpile the code. So let's install typescript and ts-node.

npm i -D typescript ts-node

Now put on your package.json the necessary script to run the tests:

"scripts": {
  ...
  "test": "mocha --require ts-node/register tests/**/*.spec.ts --exit"
}

Create one folder with the name tests, into a file with testfirst.spec.ts name and create a simple case:

import { describe } from "mocha";
import { expect } from 'chai';
import chaiAsPromised from 'chai-as-promised';

chai.use(chaiAsPromised);
const expect = chai.expect;

describe('Testing the configuration', () => {
  it('should pass', () => {

  });
});

After you could run: