class FrontMatterTest

class FrontMatterTest extends KernelTestBase {
    
    /**
     * A broken source.
     */
    const BROKEN_SOURCE = '<div>Hello {{ world</div>';
    
    /**
     * Twig service.
     *
     * @var \Drupal\Core\Template\TwigEnvironment
     */
    protected $twig;
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        $this->twig = \Drupal::service('twig');
    }
    
    /**
     * {@inheritdoc}
     */
    public function register(ContainerBuilder $container) {
        parent::register($container);
        $definition = new Definition('Twig_Loader_Filesystem', [
            [
                sys_get_temp_dir(),
            ],
        ]);
        $definition->setPublic(TRUE);
        $container->setDefinition('twig_loader__file_system', $definition)
            ->addTag('twig.loader');
    }
    
    /**
     * Creates a new temporary Twig file.
     *
     * @param string $content
     *   The contents of the Twig file to save.
     *
     * @return string
     *   The absolute path to the temporary file.
     */
    protected function createTwigTemplate(string $content = '') : string {
        $file = tempnam(sys_get_temp_dir(), 'twig') . ".html.twig";
        file_put_contents($file, $content);
        return $file;
    }
    
    /**
     * Tests broken front matter.
     *
     * @covers \Drupal\Core\Template\TwigEnvironment::getTemplateMetadata
     * @covers \Drupal\Component\FrontMatter\Exception\FrontMatterParseException
     */
    public function testFrontMatterBroken() {
        $source = "---\ncollection:\n-  key: foo\n  foo: bar\n---\n" . ComponentFrontMatterTest::SOURCE;
        $file = $this->createTwigTemplate($source);
        $this->expectException(SyntaxError::class);
        $this->expectExceptionMessage('An error occurred when attempting to parse front matter data on line 4 in ' . $file);
        $this->twig
            ->getTemplateMetadata(basename($file));
    }
    
    /**
     * Test Twig template front matter.
     *
     * @param array|null $yaml
     *   The YAML used for metadata in a Twig template.
     * @param int $line
     *   The expected line number where the source code starts.
     * @param string $content
     *   The content to use for testing purposes.
     *
     * @covers \Drupal\Core\Template\TwigEnvironment::compileSource
     * @covers \Drupal\Core\Template\TwigEnvironment::getTemplateMetadata
     *
     * @dataProvider \Drupal\Tests\Component\FrontMatter\FrontMatterTest::providerFrontMatterData
     */
    public function testFrontMatter($yaml, $line, $content = ComponentFrontMatterTest::SOURCE) {
        // Create a temporary Twig template.
        $source = ComponentFrontMatterTest::createFrontMatterSource($yaml, $content);
        $file = $this->createTwigTemplate($source);
        $name = basename($file);
        // Ensure the proper metadata is returned.
        $metadata = $this->twig
            ->getTemplateMetadata($name);
        $this->assertEquals($yaml === NULL ? [] : $yaml, $metadata);
        // Ensure the metadata is never rendered.
        $output = $this->twig
            ->load($name)
            ->render();
        $this->assertEquals($content, $output);
        // Create a temporary Twig template.
        $source = ComponentFrontMatterTest::createFrontMatterSource($yaml, static::BROKEN_SOURCE);
        $file = $this->createTwigTemplate($source);
        $name = basename($file);
        try {
            $this->twig
                ->load($name);
        } catch (Error $error) {
            $this->assertEquals($line, $error->getTemplateLine());
        }
        // Ensure string based templates work too.
        try {
            $this->twig
                ->createTemplate($source)
                ->render();
        } catch (Error $error) {
            $this->assertEquals($line, $error->getTemplateLine());
        }
    }

}