LEARN JAVASCRIPT UNIT TESTING Rooster Regulation

index.js

// Define a rooster
Rooster = {};

// Return a morning rooster call
Rooster.announceDawn = () => {
  return 'cock-a-doodle-doo!';
}

// Return hour as string
// Throws Error if hour is not between 0 and 23 inclusive
Rooster.timeAtDawn = (hour) => {
  if (hour < 0 || hour > 23) {
    throw new RangeError;
  } else {
    return hour.toString();
  };
}

module.exports = Rooster;

index_test.js

const assert = require('assert')

const Rooster = require("../index")

describe("Rooster",() => {
  describe("announceDawn", () => {
    it("returns a rooster call", () => {
      // Define expected output
      const expected = 'cock-a-doodle-doo!';
      
      // Call Rooster.announceDawn and store result in variable
      const result = Rooster.announceDawn()
      
      // Use an assert method to compare actual and expected result
      assert.strictEqual(result, expected)
    })
  })
  describe("timeAtDawn", () => {
    it("returns its argument as a string", () => {
      const expected = '16'
      const result = Rooster.timeAtDawn(16)
      assert.strictEqual(result, expected)
    })

    it("throws an error if passed a number less than 0", () => {
      assert.throws(() => {Rooster.timeAtDawn(-1)}, RangeError)
    })

    it("throws an error if  passed a number greater than 23", () => {
      assert.throws(() => {Rooster.timeAtDawn(24)}, RangeError)
    })
  })
})

package.json

{
  "name": "learn-mocha-intro-start",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "mocha test/**/*_test.js"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "mocha": "^3.5.3"
  }
}