Database Unit Testing with Doctrine 2 and PHPUnit

Database unit testing can sometimes be a bit tricky to get working well, especially when using Doctrine. In an earlier post I showed how I overcame caching issues I had experienced when using Doctrine with PHPUnit. This post builds upon some of that post, while making use PHPUnit_Extensions_Database_TestCase, and assumes you are using the pdo_sqlite in-memory driver.

If you haven’t already, you should create a Doctrine connection config specific for unit testing. Something like:

resources.doctrine.user     = ""
resources.doctrine.password = ""
resources.doctrine.host     = ""
resources.doctrine.dbname   = ""
resources.doctrine.driver   = "pdo_sqlite"
resources.doctrine.memory   = "true"

This will, of course, allow for use of your existing Doctrine implementation for testing purposes.

Extend PHPUnit_Extensions_Database_TestCase and implement the getConnection() method as required:

public function getConnection()
{
    // Get an instance of your entity manager
    $entityManager = $this->getEntityManager();

    // Retrieve PDO instance
    $pdo = $entityManager->getConnection()->getWrappedConnection();

    // Clear Doctrine to be safe
    $entityManager->clear();

    // Schema Tool to process our entities
    $tool = new \Doctrine\ORM\Tools\SchemaTool($entityManager);
    $classes = $entityManager->getMetaDataFactory()->getAllMetaData();

    // Drop all classes and re-build them for each test case
    $tool->dropSchema($classes);
    $tool->createSchema($classes);

    // Pass to PHPUnit
    return $this->createDefaultDBConnection($pdo, 'db_name');
}

So this method assumes you have already bootstrapped Doctrine elsewhere in your application setup (your application bootstrap, perhaps…). Since we are using an in-memory database, we need to tell Doctrine to process all of our entities. This, of course, will happen for each test case which is exactly what we want; no dependencies and a clean slate to test on.

Finally, we retrieve the pre-configured instance of PDO from Doctrine and pass it on to PHPUnit.

What we are left with is a solution that makes use of the existing Doctrine configuration, reducing repetition while allowing us to rebuild the schema for each test.