feature #484 [Store] Add InMemoryLoader for testing purposes (OskarStark)

This PR was squashed before being merged into the main branch.

Discussion
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[Store] Add `InMemoryLoader` for testing purposes

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| Docs?         | no
| Issues        | --
| License       | MIT

Introduces a new in-memory document loader that stores documents in memory instead of relying on filesystem or external resources. This loader is particularly useful for testing scenarios where you need predictable, controllable document sources without file system dependencies.

Commits
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0862508 [Store] Add `InMemoryLoader` for testing purposes

Author: OskarStark

src/store/src/Document/Loader/InMemoryLoader.php

@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Store\Document\Loader;
+
+use Symfony\AI\Store\Document\LoaderInterface;
+use Symfony\AI\Store\Document\TextDocument;
+
+/**
+ * @author Oskar Stark <[email protected]>
+ */
+final readonly class InMemoryLoader implements LoaderInterface
+{
+    /**
+     * @param array<TextDocument> $documents
+     */
+    public function __construct(
+        private array $documents = [],
+    ) {
+    }
+
+    public function load(string $source, array $options = []): iterable
+    {
+        yield from $this->documents;
+    }
+}

src/store/tests/Document/Loader/InMemoryLoaderTest.php

@@ -0,0 +1,79 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\AI\Store\Tests\Document\Loader;
+
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+use Symfony\AI\Store\Document\Loader\InMemoryLoader;
+use Symfony\AI\Store\Document\Metadata;
+use Symfony\AI\Store\Document\TextDocument;
+use Symfony\Component\Uid\Uuid;
+
+/**
+ * @author Oskar Stark <[email protected]>
+ */
+#[CoversClass(InMemoryLoader::class)]
+final class InMemoryLoaderTest extends TestCase
+{
+    public function testLoadWithEmptyDocuments()
+    {
+        $loader = new InMemoryLoader();
+        $documents = iterator_to_array($loader->load('ignored-source'));
+
+        $this->assertEmpty($documents);
+    }
+
+    public function testLoadWithSingleDocument()
+    {
+        $document = new TextDocument(Uuid::v4(), 'This is test content');
+        $loader = new InMemoryLoader([$document]);
+
+        $documents = iterator_to_array($loader->load('ignored-source'));
+
+        $this->assertCount(1, $documents);
+        $this->assertSame($document, $documents[0]);
+        $this->assertSame('This is test content', $documents[0]->content);
+    }
+
+    public function testLoadWithMultipleDocuments()
+    {
+        $document1 = new TextDocument(Uuid::v4(), 'First document');
+        $document2 = new TextDocument(Uuid::v4(), 'Second document', new Metadata(['type' => 'test']));
+        $loader = new InMemoryLoader([$document1, $document2]);
+
+        $documents = iterator_to_array($loader->load('ignored-source'));
+
+        $this->assertCount(2, $documents);
+        $this->assertSame($document1, $documents[0]);
+        $this->assertSame($document2, $documents[1]);
+        $this->assertSame('First document', $documents[0]->content);
+        $this->assertSame('Second document', $documents[1]->content);
+        $this->assertSame('test', $documents[1]->metadata['type']);
+    }
+
+    public function testLoadIgnoresSourceParameter()
+    {
+        $document = new TextDocument(Uuid::v4(), 'test content');
+        $loader = new InMemoryLoader([$document]);
+
+        $documents1 = iterator_to_array($loader->load('source1'));
+        $documents2 = iterator_to_array($loader->load('source2'));
+        $documents3 = iterator_to_array($loader->load('any-source'));
+
+        $this->assertCount(1, $documents1);
+        $this->assertCount(1, $documents2);
+        $this->assertCount(1, $documents3);
+        $this->assertSame($document, $documents1[0]);
+        $this->assertSame($document, $documents2[0]);
+        $this->assertSame($document, $documents3[0]);
+    }
+}