LinkRelationsTest.php

<?php

namespace Drupal\KernelTests\Core\Http;

use Drupal\Core\Http\LinkRelationType;
use Drupal\KernelTests\KernelTestBase;

/**
 * Tests link relationships in Drupal.
 *
 * @group HTTP
 */
class LinkRelationsTest extends KernelTestBase {
    
    /**
     * Tests correct Link Relations are returned from the Link Relation Type Manager.
     */
    public function testAvailableLinkRelationships() {
        
        /** @var \Drupal\Core\Http\LinkRelationTypeManager $link_relation_type_manager */
        $link_relation_type_manager = $this->container
            ->get('plugin.manager.link_relation_type');
        // A link relation type of the "registered" kind.
        
        /** @var \Drupal\Core\Http\LinkRelationTypeInterface $canonical */
        $canonical = $link_relation_type_manager->createInstance('canonical');
        $this->assertInstanceOf(LinkRelationType::class, $canonical);
        $this->assertTrue($canonical->isRegistered());
        $this->assertFalse($canonical->isExtension());
        $this->assertSame('canonical', $canonical->getRegisteredName());
        $this->assertNull($canonical->getExtensionUri());
        $this->assertEquals('[RFC6596]', $canonical->getReference());
        $this->assertEquals('Designates the preferred version of a resource (the IRI and its contents).', $canonical->getDescription());
        $this->assertEquals('', $canonical->getNotes());
        // A link relation type of the "extension" kind.
        
        /** @var \Drupal\Core\Http\LinkRelationTypeInterface $canonical */
        $add_form = $link_relation_type_manager->createInstance('add-form');
        $this->assertInstanceOf(LinkRelationType::class, $add_form);
        $this->assertFalse($add_form->isRegistered());
        $this->assertTrue($add_form->isExtension());
        $this->assertNull($add_form->getRegisteredName());
        $this->assertSame('https://drupal.org/link-relations/add-form', $add_form->getExtensionUri());
        $this->assertEquals('', $add_form->getReference());
        $this->assertEquals('A form where a resource of this type can be created.', $add_form->getDescription());
        $this->assertEquals('', $add_form->getNotes());
        // Test a couple of examples.
        $this->assertContains('about', array_keys($link_relation_type_manager->getDefinitions()));
        $this->assertContains('original', array_keys($link_relation_type_manager->getDefinitions()));
        $this->assertContains('type', array_keys($link_relation_type_manager->getDefinitions()));
    }

}