Calculator spec js file

mocha_test_blog_calculator_spec.js

//= require calculator

describe("Calculator", function () {

  it("test add function", function () {
    expect(add(1, 2)).to.equal(3);
  });

  it("test subtract function", function () {
    expect(subtract(10, 4)).to.equal(6);
  });

  it("test multiply function", function () {
    expect(multiply(5, 3)).to.equal(15);
  });

  it("test divide function", function () {
    expect(divide(10, 2)).to.equal(5);
  });

});