Unit test for issue #4018 added

tests/unit/data/ar/sphinx/ArticleIndex.php

@@ -18,6 +18,11 @@ class ArticleIndex extends ActiveRecord
         return $this->hasOne(ArticleDb::className(), ['id' => 'id']);
     }
 
+    public function getSourceCompositeLink()
+    {
+        return $this->hasOne(ArticleDb::className(), ['id' => 'id', 'author_id' => 'author_id']);
+    }
+
     public function getTags()
     {
         return $this->hasMany(TagDb::className(), ['id' => 'tag']);

tests/unit/extensions/sphinx/ActiveRelationTest.php

@@ -42,4 +42,17 @@ class ActiveRelationTest extends SphinxTestCase
         $this->assertTrue($articles[0]->index instanceof ArticleIndex);
         $this->assertTrue($articles[1]->index instanceof ArticleIndex);
     }
+
+    /**
+     * @see https://github.com/yiisoft/yii2/issues/4018
+     */
+    public function testFindCompositeLink()
+    {
+        $articles = ArticleIndex::find()->with('sourceCompositeLink')->all();
+        $this->assertEquals(2, count($articles));
+        $this->assertTrue($articles[0]->isRelationPopulated('sourceCompositeLink'));
+        $this->assertNotEmpty($articles[0]->sourceCompositeLink);
+        $this->assertTrue($articles[1]->isRelationPopulated('sourceCompositeLink'));
+        $this->assertNotEmpty($articles[1]->sourceCompositeLink);
+    }
 }