Fix response formatting

Author: tuyakhov

src/JsonApiResponseFormatter.php

@@ -61,7 +61,7 @@ public function format($response)
 
  $apiDocument = $response->data;
 
- if (!$response->isEmpty) {
+ if (!$response->isEmpty && empty($apiDocument)) {
  $apiDocument = ['data' => $response->data];
  if (\Yii::$app->controller) {
  $apiDocument['links'] = Link::serialize([

tests/JsonApiResponseFormatterTest.php

@@ -70,6 +70,33 @@ public function testFormModelError()
  ]), $response->content);
  }
 
+ public function testSuccessModel()
+ {
+ $formatter = new JsonApiResponseFormatter();
+ $response = new Response();
+ $serializer = new Serializer();
+ $model = new ResourceModel();
+ $response->data = $serializer->serialize($model);
+ $response->setStatusCode(200);
+ $formatter->format($response);
+ $this->assertJson($response->content);
+ $this->assertSame(Json::encode([
+ 'data' => [
+ 'id' => '123',
+ 'type' => 'resource-models',
+ 'attributes' => [
+ 'field1' => 'test',
+ 'field2' => 2,
+ ],
+ 'links' => [
+ 'self' => [
+ 'href' => 'http://example.com/resource/123'
+ ]
+ ]
+ ]
+ ]), $response->content);
+ }
+
  public function testEmptyData()
  {
  $formatter = new JsonApiResponseFormatter();