[5.6] [WIP] Can't lazy-load polymorphic relationships with different primary key columns

tests/Database/PolymorphicDifferentPrimaryKeysIntegrationTest.php

@@ -0,0 +1,180 @@
+<?php
+
+namespace Illuminate\Tests\Database;
+
+use PHPUnit\Framework\TestCase;
+use Illuminate\Database\Connection;
+use Illuminate\Database\Query\Builder;
+use Illuminate\Database\Capsule\Manager as DB;
+use Illuminate\Database\Eloquent\Model as Eloquent;
+
+class PolymorphicDifferentPrimaryKeysIntegrationTest extends TestCase
+{
+    /**
+     * Setup the database schema.
+     *
+     * @return void
+     */
+    public function createSchema()
+    {
+        $this->schema()->create('posts', function ($table) {
+            $table->increments('post_id');
+            $table->string('title');
+            $table->string('body');
+            $table->timestamps();
+        });
+
+        $this->schema()->create('videos', function ($table) {
+            $table->increments('video_id');
+            $table->string('title');
+            $table->string('video');
+            $table->timestamps();
+        });
+
+        $this->schema()->create('comments', function ($table) {
+            $table->increments('id');
+            $table->integer('commentable_id');
+            $table->string('commentable_type');
+            $table->text('body');
+            $table->timestamps();
+        });
+    }
+
+    protected function seedData()
+    {
+        $post1 = FooPost::create(['title' => 'Test Post', 'body' => 'hello world']);
+        $post1->comments()->create(['body' => 'comment on a POST']);
+
+        $video1 = FooVideo::create(['title' => 'Test Video', 'video' => 'my-video.mov']);
+        $video1->comments()->create(['body' => 'comment on a VIDEO']);
+    }
+
+    // This test is OK
+    public function testWithNoEagerOrLazyLoad()
+    {
+        $this->seedData();
+
+        $comments = FooComment::all();
+
+        $this->assertEquals(FooPost::first(), $comments->first()->commentable);
+        $this->assertEquals(FooVideo::first(), $comments->last()->commentable);
+    }
+
+    // This test is OK
+    public function testItCanEagerLoad()
+    {
+        $this->seedData();
+
+        $comments = FooComment::with('commentable')->get();
+
+        $this->assertEquals(FooPost::first(), $comments->first()->commentable);
+        $this->assertEquals(FooVideo::first(), $comments->last()->commentable);
+    }
+
+    // This is the test that is failing
+    public function testItCanLazyLoad()
+    {
+        $this->seedData();
+
+        /*
+         * This is the test that fails.
+         * The query to lazy-load the Post is successful, but it assumes the
+         * db key is the same as it was for the Video table, which it is not,
+         * so the query fails.
+         */
+
+        $comments = FooComment::all();
+        $comments->load('commentable');
+
+        $this->assertEquals(FooPost::first(), $comments->first()->commentable);
+        $this->assertEquals(FooVideo::first(), $comments->last()->commentable);
+    }
+
+    public function setUp()
+    {
+        $db = new DB;
+
+        $db->addConnection([
+            'driver'   => 'sqlite',
+            'database' => ':memory:',
+        ]);
+
+        $db->bootEloquent();
+        $db->setAsGlobal();
+
+        $this->createSchema();
+    }
+
+    /**
+     * Tear down the database schema.
+     *
+     * @return void
+     */
+    public function tearDown()
+    {
+        $this->schema()->drop('posts');
+        $this->schema()->drop('videos');
+        $this->schema()->drop('comments');
+    }
+
+    /**
+     * Get a database connection instance.
+     *
+     * @return Connection
+     */
+    protected function connection()
+    {
+        return Eloquent::getConnectionResolver()->connection();
+    }
+
+    /**
+     * Get a schema builder instance.
+     *
+     * @return Schema\Builder
+     */
+    protected function schema()
+    {
+        return $this->connection()->getSchemaBuilder();
+    }
+}
+
+/**
+ * Eloquent Models...
+ */
+class FooPost extends Eloquent
+{
+    protected $table = 'posts';
+    protected $primaryKey = 'post_id';
+    protected $guarded = [];
+
+    public function comments()
+    {
+        return $this->morphMany(FooComment::class, 'commentable');
+    }
+}
+
+class FooVideo extends Eloquent
+{
+    protected $table = 'videos';
+    protected $primaryKey = 'video_id';
+    protected $guarded = [];
+
+    public function comments()
+    {
+        return $this->morphMany(FooComment::class, 'commentable');
+    }
+}
+
+/**
+ * Eloquent Models...
+ */
+class FooComment extends Eloquent
+{
+    protected $table = 'comments';
+    protected $guarded = [];
+
+    public function commentable()
+    {
+        return $this->morphTo();
+    }
+}