Adam Wathan - Three Approaches To Testing

How to test for NewFollower Event

Event::fire(new NewFollower (Auth::user->id, $userToFollow->id))

1 Expect Events

$this->expectsEvents(NewFollower::class)

Test only passes, if event fires.

Problem

Parameters could be wrong and test would still pass.

2 Could use a traditional mock solution.

Event::shouldReceive('fire')->with(new NewFollower($follower->id, $followed->id))->once();

This will fail because we are creating a new NewFollower in the test, so it will have a different object id, than the one in the event.

Should be like this:

Event::shouldReceive('fire')->with(Mockery::on(function ($event) use ($follower, $followed) {
      return $event->followerId == $follower->id
      && $event->followedId == $followed->id;

})->once();

Event::shouldIgnoreMissing();

Adam does not like this because it does not follow: ```// Arrange // Act // Assert

### 3 Adam Prefers - use a spy instead of a mock

public function test_a_user_can_follow_another_user { //Arrange Event::spy(); $follower = factory(User::class)->create([‘username’ => ‘steve’]); $followed = factory(User::class)->create([ ‘username’ => ‘jane’, ‘email’ => ‘jane@example.com’ ]);

   //Act
   $this->actingAs($follower)
        ->post('following',['username' => 'jane']);
        
   //Assert
   $this->assertTrue($follower->follows($followed));
   Event::shouldReceive('fire')->with(Mockery::on(function ($event) use ($follower, $followed) {
        return $event->followerId == $follower->id
        && $event->followedId == $followed->id;
    })->once();

}

Controller:

Event::fire(new NewFollower(Auth::user()->id, $userToFollow->id));

**Problem**
Listener: sends email notification of new follower.
Test will pass, even if listener does not fire (could be a simple typo).

**We can spy on the listener!**

//Arrange $listener = Mockery::spy(EmailNewFollowerNotification::class); //the listener //bind this in the IOC app()->instance(EmailNewFollowerNotification::class, $listener);

//Assert $this->assertTrue($follower->follows($followed)); $listener::shouldReceive(‘fire’)->with(Mockery::on(function ($event) use ($follower, $followed) { return $event->followerId == $follower->id && $event->followedId == $followed->id; })->once();

```

This can test that the listener gets fired, but not what it actually does.