Better failing tests with Mockery::on()

Oct 15, 2018 mockery php testing

This post is more than 18 months old. Since technology changes too rapidly, this content may be out of date (but that's not always the case). Please remember to verify any technical or programming information with the current release.

In an earlier post titled Use $this->fail() with Mockery::on(), I explained the challenges of debugging a failing test with the closure passed to Mockery::on(). Instead of returning false, I opted to use $this->fail() - which seemed like a good idea at the time. After all, I was doing my test, then failing with a useful bit of information. (Previous to this, it would just say that you don’t have a matching handler for this assertion, which was really confusing).

Then it hit me: I’m reinventing the wheel. Listen to what I said: I’m testing something, then calling a failure method. That sounds like a lot like assertion to me. Duh! Let’s use the previous example:

$mockedClass->shouldReceive('process')->once()
  ->with(\Mockery::on(function($parameter) {
    $valid = false;
    if (
      ($parameter instanceof SomeClass)
      &&
      ($parameter->getProperty() == 12)
    ) {
      $valid = true;
    }
    return $valid;
  })->andReturn(true);

You can read about our expectations in the earlier blog posting - but let’s refactor this using assertions now.

$mockedClass->shouldReceive('process')->once()
  ->with(\Mockery::on(function($parameter) {
    $this->assertInstanceOf(SomeClass::class, $parameter);
    $this->assertEquals(12, $parameter->getProperty());
    return true;
  })->andReturn(true);

This is so much better and it still gives us good errors when it fails.