Support withAttributes on many-to-many

src/Illuminate/Database/Eloquent/Relations/BelongsToMany.php

@@ -1350,6 +1350,8 @@ public function saveManyQuietly($models, array $pivotAttributes = [])
      */
     public function create(array $attributes = [], array $joining = [], $touch = true)
     {
+        $attributes = array_merge($this->getQuery()->pendingAttributes, $attributes);
+
         $instance = $this->related->newInstance($attributes);
 
         // Once we save the related model, we need to attach it to the base model via

tests/Database/DatabaseEloquentBelongsToManyWithAttributesTest.php

@@ -0,0 +1,120 @@
+<?php
+
+namespace Illuminate\Tests\Database;
+
+use Illuminate\Database\Capsule\Manager as DB;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+use PHPUnit\Framework\TestCase;
+
+class DatabaseEloquentBelongsToManyWithAttributesTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        $db = new DB;
+
+        $db->addConnection([
+            'driver' => 'sqlite',
+            'database' => ':memory:',
+        ]);
+        $db->bootEloquent();
+        $db->setAsGlobal();
+        $this->createSchema();
+    }
+
+    public function testCreatesWithAttributesAndPivotValues(): void
+    {
+        $post = ManyToManyWithAttributesPost::create();
+        $tag = $post->metaTags()->create(['name' => 'long article']);
+
+        $this->assertSame('long article', $tag->name);
+        $this->assertTrue($tag->visible);
+
+        $pivot = DB::table('with_attributes_pivot')->first();
+        $this->assertSame('meta', $pivot->type);
+        $this->assertSame($post->id, $pivot->post_id);
+        $this->assertSame($tag->id, $pivot->tag_id);
+    }
+
+    protected function createSchema()
+    {
+        $this->schema()->create('with_attributes_posts', function ($table) {
+            $table->increments('id');
+            $table->timestamps();
+        });
+
+        $this->schema()->create('with_attributes_tags', function ($table) {
+            $table->increments('id');
+            $table->string('name');
+            $table->boolean('visible')->nullable();
+            $table->timestamps();
+        });
+
+        $this->schema()->create('with_attributes_pivot', function ($table) {
+            $table->integer('post_id');
+            $table->integer('tag_id');
+            $table->string('type');
+        });
+    }
+
+    /**
+     * Tear down the database schema.
+     *
+     * @return void
+     */
+    protected function tearDown(): void
+    {
+        $this->schema()->drop('with_attributes_posts');
+        $this->schema()->drop('with_attributes_tags');
+        $this->schema()->drop('with_attributes_pivot');
+    }
+
+    /**
+     * Get a database connection instance.
+     *
+     * @return \Illuminate\Database\Connection
+     */
+    protected function connection($connection = 'default')
+    {
+        return Model::getConnectionResolver()->connection($connection);
+    }
+
+    /**
+     * Get a schema builder instance.
+     *
+     * @return \Illuminate\Database\Schema\Builder
+     */
+    protected function schema($connection = 'default')
+    {
+        return $this->connection($connection)->getSchemaBuilder();
+    }
+}
+
+class ManyToManyWithAttributesPost extends Model
+{
+    protected $guarded = [];
+    protected $table = 'with_attributes_posts';
+
+    public function tags(): BelongsToMany
+    {
+        return $this->belongsToMany(
+            ManyToManyWithAttributesTag::class,
+            'with_attributes_pivot',
+            'tag_id',
+            'post_id',
+        );
+    }
+
+    public function metaTags(): BelongsToMany
+    {
+        return $this->tags()
+            ->withAttributes('visible', true)
+            ->withPivotValue('type', 'meta');
+    }
+}
+
+class ManyToManyWithAttributesTag extends Model
+{
+    protected $guarded = [];
+    protected $table = 'with_attributes_tags';
+}