Mockery: returning values and throwing exceptions

Last week, I had to wrote a piece of code that contains retry logic. Naturally, I want to test it. That proved trickier than expected.

The application code looks like this:

    class Sender

    {

        protected $connection;

        public function send()

        {

            $success = false;

            $i = 0;

            do {

                $i++;

                try {

                    $success = $this->doSend($i);

                } catch (SenderException $e) {

                    $success = false;

                }

            } while (!$success && $i < 3);

            return $success;

        }

        protected function doSend($data)

        {

            // Can throw SenderException

            $response = $this->connection->send($data);

            if ('OK' === $response) {

                return true;

            }

            return false;

        }

    }

I specifically want to test the retry logic, so I have to mock the ::doSend() method. Then I can simulate the different outcomes (returning true or false, or throwing a SenderException).

I use Mockery to do the real work. It is a great library. If you don't know it yet, please check it out. I will wait right here...

Now, since ::doSend() is a protected method, Mockery must be instructed to allow that.

So after the first try, I ended up with:

    public function testItWillRetrySending()

    {

        $sender = M::mock('Sender');

        $sender->shouldAllowMockingProtectedMethods()

        $sender->shouldReceive('doSend')

            ->andReturn(false, new Exception());

    }

To my surprise, this did not work. Instead of throwing the exception, Mockery returns it. So my next try was this:

    $sender->shouldReceive('doSend')

        ->andReturn(false)

        ->andThrow(new Exception());

Another surprise: with this code, Mockery will always throw the exception, and ignore the first return value (false). After some debugging, I found out that Mockery just overwrites the return values in this case.

Fortunately, there is another way to return multiple return values: the ::andReturnUsing() method. It gives full control over the return values.

So I ended up with this testing code:

    $return_value_generator = function () {

        static $counter = 0;

        $counter++;

        switch ($counter) {

            case 1: return false;

            case 2: throw new SenderException();

            case 3: return true;

            default: throw new Exception("Should never reach this."); 

        }

    };

    $sender = M::mock('Sender');

    $sender->shouldAllowMockingProtectedMethods()

        ->shouldReceive('doSend')

        ->andReturnUsing($return_value_generator);

This works perfectly. It feels a bit like a hack though. So if you know a better way or have any other remarks, please let me know.

refer : https://jacobkiers.net/post/multiple-return-values-with-mockery