ThemeRegistryLoaderTest.php

<?php

namespace Drupal\Tests\Core\Template\Loader;

use Drupal\Core\Template\Loader\ThemeRegistryLoader;
use Drupal\Tests\UnitTestCase;

/**
 * @coversDefaultClass \Drupal\Core\Template\Loader\ThemeRegistryLoader
 * @group Template
 */
class ThemeRegistryLoaderTest extends UnitTestCase {
    
    /**
     * @covers ::findTemplate
     */
    public function testLoaderReturnsFalseForExistsOnNonexistent() {
        $registry = $this->prophesize('Drupal\\Core\\Theme\\Registry');
        $runtime = $this->prophesize('Drupal\\Core\\Utility\\ThemeRegistry');
        $runtime->has('foo')
            ->shouldBeCalled()
            ->willReturn(FALSE);
        $registry->getRuntime()
            ->willReturn($runtime);
        $loader = new ThemeRegistryLoader($registry->reveal());
        $this->assertFalse($loader->exists('foo'));
    }

}