105 lines
2.8 KiB
Markdown
105 lines
2.8 KiB
Markdown
+++
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title = Mockery: returning values and throwing exceptions
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date = 2015-04-24
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author = Jacob Kiers
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+++
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Last week, I had to write a piece of code that contains retry logic. Naturally, I want to test it. That proved trickier than expected.
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The application code looks like this:
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```php
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class Sender
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{
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protected $connection;
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public function send()
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{
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$success = false;
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$i = 0;
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do {
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$i++;
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try {
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$success = $this->doSend($i);
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} catch (SenderException $e) {
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$success = false;
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}
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} while (!$success && $i < 3);
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return $success;
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}
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protected function doSend($data)
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{
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// Can throw SenderException
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$response = $this->connection->send($data);
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if ('OK' === $response) {
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return true;
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}
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return false;
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}
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}
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```
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I specifically want to test the retry logic, so I have to mock the ::doSend() method. Then I can simulate the different outcomes (returning true or false, or throwing a SenderException).
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I use [Mockery] to do the real work. It is a great library. If you don't know it yet, please check it out. I will wait right here...
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Now, since ::doSend() is a protected method, Mockery must be instructed to allow that.
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So after the first try, I ended up with:
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```php
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public function testItWillRetrySending()
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{
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$sender = M::mock('Sender');
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$sender->shouldAllowMockingProtectedMethods()
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$sender->shouldReceive('doSend')
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->andReturn(false, new Exception());
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}
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```
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To my surprise, this did not work. Instead of throwing the exception, Mockery returns it. So my next try was this:
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```php
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$sender->shouldReceive('doSend')
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->andReturn(false)
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->andThrow(new Exception());
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```
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Another surprise: with this code, Mockery will always throw the exception, and ignore the first return value (false). After some debugging, I found out that Mockery just overwrites the return values in this case.
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Fortunately, there is another way to return multiple return values: the ::andReturnUsing() method. It gives full control over the return values.
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So I ended up with this testing code:
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```php
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$return_value_generator = function () {
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static $counter = 0;
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$counter++;
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switch ($counter) {
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case 1: return false;
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case 2: throw new SenderException();
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case 3: return true;
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default: throw new Exception("Should never reach this.");
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}
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};
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$sender = M::mock('Sender');
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$sender->shouldAllowMockingProtectedMethods()
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->shouldReceive('doSend')
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->andReturnUsing($return_value_generator);
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```
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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.
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[Mockery]: https://github.com/mockery/mockery |