jest

Introduction

Jest is now one of the most popular testing frameworks out there. Light has a built in test function that can be used to build and test individual routes very easily.

Setup

First, create a test file for your route. As of right now the file cannot live inside of the routes folder as all files are automatically imported. Once your file is created, populate it with the following.

const fetch = require('node-fetch');
const { test } = require('light');

const index = require('../routes/index');

let server;
beforeAll(async () => {
  server = await test(index);
})
afterAll(async () => {
  server.close();
});

describe('index', () => {
  it('responds with JSON', async () => {
    expect.assertions(2);
    const req = await fetch(server.url);
    const res = await req.json();
    expect(req.status).toStrictEqual(200);
    expect(res).toMatchObject({
      hello: 'world',
      this: 'is being tested by jest',
    });
  });
});

You will need the node-fetch dependency to actually make the requests to the server, but you may swap it out with any other similar library. The test function takes in a route and boots up a server, returning an object with a url property and a close function. The beforeAll and afterAll functions will boot up the server for the tests and if you need to reset the server between every test, you can change them to beforeEach and afterEach. Finally, inside the test you can do anything you will like with the server.url. Keep in mind that whatever route is passed becomes mapped to / and does not follow the routes defined in routes.js.