README.snapshot-trait.md

Snapshot Trait

To use snapshot tests, use the SnapshotTrait in your test class.

Optionally modify the default path of the __snapshot__ directories appropriate to your PSR-4 autoload configuration in composer.json by overwriting the snapshotPath() method.

// FunctionalTestCase.php

use Brainbits\FunctionalTestHelpers\Snapshot\SnapshotTrait;
use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;

abstract class FunctionalTestCase extends WebTestCase
{
    use SnapshotTrait;

    /**
     * Overwrite Snapshot::snapshotPath() to locate __snapshot__ directory next to the test classes.
     */
    private function snapshotPath(): string
    {
        // parent directory is the base path of all tests    
        $basePath = dirname(__DIR__);

        // convert namespace to path
        $path = preg_replace('/\\\\[^\\\\]+$/', '', static::class);
        $path = str_replace('\\', '/', $path);
        
        // strip 'App/Tests' from path
        $path = substr($path, strlen('App/Tests/'));

        return $basePath . '/' . $path;
    }
}

Call assertions to verify snapshot. The snapshot file is created automatically on the first run.

public function testJsonFactoryCreatesJsonCorrectly()
{
    $jsonFactory = new JsonFactory();

    $json = $jsonFactory->createJson();

    $this->assertMatchesJsonSnapshot($json);
}

Recreate/Update Snapshots

To recreate/update snapshot files run PHPUnit with the environment variable UPDATE_SNAPSHOTS.

Snapshot Assertions

• Array assertMatchesArraySnapshot()
• JSON assertMatchesJsonSnapshot()
• XML assertMatchesXmlSnapshot()

UPDATE_SNAPSHOTS=1 phpunit
UPDATE_SNAPSHOTS=1 phpunit tests/Functinoal/MyTest.php

Usage in CI

When running in continuous integration you maybe want to disable snapshot generation by setting CREATE_SNAPSHOTS to 0 or false.

CREATE_SNAPSHOTS=0 phpunit
CREATE_SNAPSHOTS=false phpunit tests/Functinoal/MyTest.php