Add memoization for build referencable schemas

src/Concerns/Referencable.php

@@ -14,6 +14,8 @@
 
 trait Referencable
 {
+    static $buildReferencableSchemas = [];
+
     public static function ref(?string $objectId = null): Schema
     {
         $instance = app(static::class);
@@ -38,6 +40,6 @@ public static function ref(?string $objectId = null): Schema
             $baseRef = '#/components/securitySchemes/';
         }
 
-        return Schema::ref($baseRef.$instance->build()->objectId, $objectId);
+        return self::$buildReferencableSchemas[static::class . "_{$objectId}"] ??= Schema::ref($baseRef.$instance->build()->objectId, $objectId);
     }
 }

tests/Fixtures/ExampleSchema.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace Vyuldashev\LaravelOpenApi\Tests\Fixtures;
+
+use GoldSpecDigital\ObjectOrientedOAS\Contracts\SchemaContract;
+use GoldSpecDigital\ObjectOrientedOAS\Objects\Schema;
+use Vyuldashev\LaravelOpenApi\Contracts\Reusable;
+use Vyuldashev\LaravelOpenApi\Factories\SchemaFactory;
+
+class ExampleSchema extends SchemaFactory implements Reusable
+{
+    public function build(): SchemaContract
+    {
+        return Schema::object('ExampleSchema')
+            ->properties(
+                Schema::string('example_string'),
+                Schema::integer('example_integer'),
+                Schema::boolean('example_boolean'),
+            );
+    }
+}

tests/MemoizationTest.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Vyuldashev\LaravelOpenApi\Tests;
+
+use Vyuldashev\LaravelOpenApi\Tests\Fixtures\ExampleSchema;
+
+class MemoizationTest extends TestCase
+{
+    public function testReferencableInstanceBuildOnce(): void
+    {
+        self::assertEquals($e1ObjectId = (new ExampleSchema)::ref('e1'), (new ExampleSchema)::ref('e1'));
+        self::assertNotEquals($e1ObjectId, (new ExampleSchema)::ref('e2'));
+    }
+}