medium-test-directive-user-display.controller.spec1.js

describe('The toggleFollow function', function() {
  it('should unfollow the followed user', function() {
    // mock
    followService.isFollowing = function() {
      return true;
    };
    
    var controller = initController();
    controller.toggleFollow();

    expect(followService.unfollow).to.have.been.calledOnce;
    expect(controller.isFollowing).to.be.false;
  });

  it('should follow the unfollowed user', function() {
    // mock
    followService.isFollowing = function() {
      return false;
    };
    
    var controller = initController();
    controller.toggleFollow();

    expect(followService.follow).to.have.been.calledOnce;
    expect(controller.isFollowing).to.be.true;
  });
});