test(jsonld): cover Issue5438 inheritance IRIs

The deleted features/jsonld/inheritance.feature only had
"print last JSON response" steps. Replace with a real assertion
that confirms each collection member uses its concrete subtype's
URI template (Contractor5438 → /contractor_5438/{id}, Employee5438
→ /employee_5438/{id}) — the original behavior fixed in #5449.

Author: soyuka

tests/Functional/JsonLd/InheritanceIriTest.php

@@ -0,0 +1,64 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <dunglas@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\Tests\Functional\JsonLd;
+
+use ApiPlatform\Symfony\Bundle\Test\ApiTestCase;
+use ApiPlatform\Tests\Fixtures\TestBundle\ApiResource\Issue5438\Contractor;
+use ApiPlatform\Tests\Fixtures\TestBundle\ApiResource\Issue5438\Employee;
+use ApiPlatform\Tests\Fixtures\TestBundle\ApiResource\Issue5438\Person;
+use ApiPlatform\Tests\SetupClassResourcesTrait;
+
+final class InheritanceIriTest extends ApiTestCase
+{
+    use SetupClassResourcesTrait;
+
+    protected static ?bool $alwaysBootKernel = false;
+
+    /**
+     * @return class-string[]
+     */
+    public static function getResources(): array
+    {
+        return [Person::class, Contractor::class, Employee::class];
+    }
+
+    public function testCollectionItemsUseConcreteSubtypeIris(): void
+    {
+        $response = self::createClient()->request('GET', '/people_5438', [
+            'headers' => ['Accept' => 'application/ld+json'],
+        ]);
+
+        $this->assertResponseIsSuccessful();
+        $body = $response->toArray();
+        $this->assertSame('/contexts/People5438', $body['@context']);
+        $this->assertSame('/people_5438', $body['@id']);
+        $this->assertSame('hydra:Collection', $body['@type']);
+        $this->assertSame(2, $body['hydra:totalItems']);
+
+        $this->assertSame([
+            [
+                '@id' => '/contractor_5438/1',
+                '@type' => 'Contractor',
+                'id' => 1,
+                'name' => 'a',
+            ],
+            [
+                '@id' => '/employee_5438/2',
+                '@type' => 'Employee',
+                'id' => 2,
+                'name' => 'b',
+            ],
+        ], $body['hydra:member']);
+    }
+}