mailer = $this ->getMockBuilder('Swift_Mailer') ->disableOriginalConstructor() ->getMock(); } public function testMessageCreationIsLazyWhenUsingCallback() { $this->mailer->expects($this->never()) ->method('send'); $callback = function () { throw new \RuntimeException('Swift_Message creation callback should not have been called in this test'); }; $handler = new SwiftMailerHandler($this->mailer, $callback); $records = array( $this->getRecord(Logger::DEBUG), $this->getRecord(Logger::INFO), ); $handler->handleBatch($records); } public function testMessageCanBeCustomizedGivenLoggedData() { // Wire Mailer to expect a specific Swift_Message with a customized Subject $expectedMessage = new \Swift_Message(); $this->mailer->expects($this->once()) ->method('send') ->with($this->callback(function ($value) use ($expectedMessage) { return $value instanceof \Swift_Message && $value->getSubject() === 'Emergency' && $value === $expectedMessage; })); // Callback dynamically changes subject based on number of logged records $callback = function ($content, array $records) use ($expectedMessage) { $subject = count($records) > 0 ? 'Emergency' : 'Normal'; $expectedMessage->setSubject($subject); return $expectedMessage; }; $handler = new SwiftMailerHandler($this->mailer, $callback); // Logging 1 record makes this an Emergency $records = array( $this->getRecord(Logger::EMERGENCY), ); $handler->handleBatch($records); } }