Organizing test with describe()

In this section, we will learn how to use describe(). describe is a function injected into our test files, just like the it function is. It comes from mocha and it's really fantastic. Essentially, it lets us group tests together. That makes it a lot easier to scan the test output. If we run our npm test command in the Terminal, we get our tests:

We have seven tests and currently they're all grouped together. It's really hard to look for the tests in the utils file and it's impossible to find the tests for asyncAdd without scanning all of the text. What we'll do is call describe(). This will let us make groups of tests. We can give that group a name. It will make our test output much more readable.

In the utils.test.js file, right after the utils constant, we'll call describe():

const expect = require('expect');

const utils = require('./utils');

describe()

The describe object takes two arguments, just like it. The first one is the name and the other is the callback...