Add $schema-URI Draft auto-detection for Draft 2019-09

AutoDetectionDraft previously always resolved to Draft_07 regardless of a
schema's declared $schema keyword. Schemas declaring the 2019-09 meta-schema
URI (http/https, with or without trailing #) now resolve to a cached
Draft_2019_09 instance; every other case (absent, unrecognised, or the
draft-07 URI) keeps the existing Draft_07 fallback unchanged.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: wol-soft

src/Draft/AutoDetectionDraft.php

@@ -8,14 +8,30 @@
 
 class AutoDetectionDraft implements DraftFactoryInterface
 {
+    /** URI variants (with and without trailing '#', http and https) identifying a draft 2019-09 schema */
+    private const array DRAFT_2019_09_SCHEMA_URIS = [
+        'https://json-schema.org/draft/2019-09/schema',
+        'https://json-schema.org/draft/2019-09/schema#',
+        'http://json-schema.org/draft/2019-09/schema',
+        'http://json-schema.org/draft/2019-09/schema#',
+    ];
+
     /** @var DraftInterface[] Keyed by draft class name; reused across schemas */
     private array $draftInstances = [];
 
     public function getDraftForSchema(JsonSchema $jsonSchema): DraftInterface
     {
-        // Only Draft_07 is currently supported; all schemas (including unrecognised
-        // or absent $schema keywords) fall back to it. Additional drafts will be
-        // detected here when additional drafts are added (e.g. draft-04, draft 2020-12).
+        $schemaUri = $jsonSchema->getJson()['$schema'] ?? null;
+
+        // Detect draft 2019-09 by its declared $schema URI. Every other case --
+        // an absent $schema keyword, the draft-07 URI, or any unrecognised URI --
+        // falls back to Draft_07, preserving the previous unconditional behaviour.
+        // Additional drafts will be detected here when support for them is added
+        // (e.g. draft-04, draft 2020-12).
+        if (in_array($schemaUri, self::DRAFT_2019_09_SCHEMA_URIS, true)) {
+            return $this->draftInstances[Draft_2019_09::class] ??= new Draft_2019_09();
+        }
+
         return $this->draftInstances[Draft_07::class] ??= new Draft_07();
     }
 }

tests/Draft/DraftTest.php

@@ -6,6 +6,7 @@
 
 use PHPModelGenerator\Draft\AutoDetectionDraft;
 use PHPModelGenerator\Draft\Draft_07;
+use PHPModelGenerator\Draft\Draft_2019_09;
 use PHPModelGenerator\Draft\Element\Type;
 use PHPModelGenerator\Exception\SchemaException;
 use PHPModelGenerator\Exception\String\MinLengthException;
@@ -170,6 +171,51 @@ public function testAutoDetectionFallsBackToDraft07ForUnrecognisedSchemaKeyword(
         $this->assertInstanceOf(Draft_07::class, (new AutoDetectionDraft())->getDraftForSchema($jsonSchema));
     }
 
+    /** @return array<string, array{string}> */
+    public static function draft201909SchemaUriProvider(): array
+    {
+        return [
+            'https without trailing hash' => ['https://json-schema.org/draft/2019-09/schema'],
+            'https with trailing hash'    => ['https://json-schema.org/draft/2019-09/schema#'],
+            'http without trailing hash'  => ['http://json-schema.org/draft/2019-09/schema'],
+            'http with trailing hash'     => ['http://json-schema.org/draft/2019-09/schema#'],
+        ];
+    }
+
+    #[DataProvider('draft201909SchemaUriProvider')]
+    public function testAutoDetectionReturnsDraft201909ForDraft201909SchemaKeyword(string $schemaUri): void
+    {
+        $jsonSchema = new JsonSchema('test.json', ['$schema' => $schemaUri]);
+
+        $this->assertInstanceOf(Draft_2019_09::class, (new AutoDetectionDraft())->getDraftForSchema($jsonSchema));
+    }
+
+    public function testAutoDetectionReusesCachedDraft07Instance(): void
+    {
+        $autoDetectionDraft = new AutoDetectionDraft();
+
+        $firstSchema = new JsonSchema('first.json', ['$schema' => 'http://json-schema.org/draft-07/schema#']);
+        $secondSchema = new JsonSchema('second.json', ['type' => 'object']);
+
+        $this->assertSame(
+            $autoDetectionDraft->getDraftForSchema($firstSchema),
+            $autoDetectionDraft->getDraftForSchema($secondSchema),
+        );
+    }
+
+    public function testAutoDetectionReusesCachedDraft201909Instance(): void
+    {
+        $autoDetectionDraft = new AutoDetectionDraft();
+
+        $firstSchema = new JsonSchema('first.json', ['$schema' => 'https://json-schema.org/draft/2019-09/schema']);
+        $secondSchema = new JsonSchema('second.json', ['$schema' => 'https://json-schema.org/draft/2019-09/schema#']);
+
+        $this->assertSame(
+            $autoDetectionDraft->getDraftForSchema($firstSchema),
+            $autoDetectionDraft->getDraftForSchema($secondSchema),
+        );
+    }
+
     // --- GeneratorConfiguration ---
 
     public function testGeneratorConfigurationDefaultDraftIsAutoDetection(): void