sumMultiplesOfFive.js

import expect from 'expect';
import {isMultipleOfFive, getMultiplesOfFive, getSumOfMultiples, sum} from '../src'

describe('Given a number', function(){
  it('return true if it is a multiple of 5', function(){
    expect(isMultipleOfFive(5)).toBe(true);
    expect(isMultipleOfFive(10)).toBe(true);
    expect(isMultipleOfFive(1)).toBe(false);
    expect(isMultipleOfFive(9)).toBe(false);
  });
});

describe('Given two numbers', function(){
  it('Gets all the multiples of five between them', function(){
    expect(getMultiplesOfFive(1, 5)).toInclude(5);
    expect(getMultiplesOfFive(1, 10)).toInclude(5).toInclude(10);
  });

  it('Gets the sum of both numbers', function() {
    expect(sum(1, 1)).toBe(2);
    expect(sum(5, 10)).toBe(15);
  });

  it('Gets the sum of all the multiples of five between them', function(){
    expect(getSumOfMultiples(1, 5)).toBe(5);
    expect(getSumOfMultiples(1, 10)).toBe(15);
    expect(getSumOfMultiples(1, 20)).toBe(50);
  });

});