如何断言两个 JSON 字符串表示的数据相等？

Posted 2023-03-15

【中文标题】如何断言两个 JSON 字符串表示的数据相等？

【英文标题】：How can I assert that data represented by two JSON strings is equal?

【发布时间】：2018-02-06 15:49:39

【问题描述】：

我第一次尝试对我的项目使用单元测试，但我被一个断言模型已正确存储的测试所阻止。

这是我要测试的 API 控制器：

public function store(QuestionFormRequest $request)

    $questionRequest = $request->question();

    $question = new Question($questionRequest);
    $question->save();

    $question->answers()->createMany($questionRequest['answers']);

    return response()->json($question->load('answers'), 201);

这是我的测试：

public function it_can_store_a_question()

    $surveyFactory = factory(Survey::class)->create();
    $themeFactory = factory(Theme::class)->create();
    $pillarFactory = factory(Pillar::class)->create();

    $questionToStore = [
        'survey_id' => $surveyFactory->id,
        'theme_id' => $themeFactory->id,
        'pillar_id' => $pillarFactory->id,
        'name' => 'question',
        'type' => 'simple',
        'answers' => [
            [
                'label' => 'reponse1',
                'points' => '3',
            ],
            [
                'label' => 'reponse2',
                'points' => '5',
            ]
        ]
    ];

    $response = $this->post('/api/1.0/question', $questionToStore);
    $response->assertStatus(201);

    $expectedQuestion = Question::with('answers')->get()->first();
    $this->assertEquals(json_encode($expectedQuestion), $response->getContent());
 

这是结果：

Failed asserting that two strings are equal.
Expected :'"id":1,"survey_id":1,"theme_id":1,"pillar_id":1,"name":"question","type":"simple","created_at":"2017-08-29 08:54:45","updated_at":"2017-08-29 08:54:45","deleted_at":null,"answers":["id":1,"question_id":1,"label":"reponse1","points":3,"description":"","created_at":"2017-08-29 08:54:45","updated_at":"2017-08-29 08:54:45","deleted_at":null,"id":2,"question_id":1,"label":"reponse2","points":5,"description":"","created_at":"2017-08-29 08:54:45","updated_at":"2017-08-29 08:54:45","deleted_at":null]'
Actual   :'"survey_id":1,"theme_id":1,"pillar_id":1,"name":"question","type":"simple","updated_at":"2017-08-29 08:54:45","created_at":"2017-08-29 08:54:45","id":1,"answers":["id":1,"question_id":1,"label":"reponse1","points":3,"description":"","created_at":"2017-08-29 08:54:45","updated_at":"2017-08-29 08:54:45","deleted_at":null,"id":2,"question_id":1,"label":"reponse2","points":5,"description":"","created_at":"2017-08-29 08:54:45","updated_at":"2017-08-29 08:54:45","deleted_at":null]'

其实结果是对的。但不是同一个顺序。 我在测试中做错了什么？

谢谢。

【参考方案1】：

JSON 输出只是有点不同 - 而不是比较实际的字符串输出，您最好使用 Laravel 的 JSON 断言之一来确保输出包含您期望的内容。看看the available assertions in the documentation。您可以使用$response->assertJson() 或$response->assertJsonFragment() 来确保返回所需的项目。

【参考方案2】：

对于您的示例，您可以使用phpunit/phpunit 附带的断言：

assertJsonFileEqualsJsonFile() assertJsonStringEqualsJsonString() assertJsonStringEqualsJsonFile()

或

assertEquals()

assertJsonFileEqualsJsonFile()

但是，当我——为了一个例子——将两个 JSON 字符串提取到单独的文件中

expected.json actual.json

然后在 PhpStorm 中使用 option + command + L 格式化 JSON 并运行以下测试

use PHPUnit\Framework;

final class JsonTest extends Framework\TestCase

    public function testJsonEquals()
    
        $expected = __DIR__ . '/expected.json';
        $actual = __DIR__ . '/actual.json';

        $this->assertJsonFileEqualsJsonFile($expected, $actual);
    

测试失败

Failed asserting that '\n
  "id": 1,\n
  "survey_id": 1,\n
  "theme_id": 1,\n
  "pillar_id": 1,\n
  "name": "question",\n
  "type": "simple",\n
  "created_at": "2017-08-29 08:54:45",\n
  "updated_at": "2017-08-29 08:54:45",\n
  "deleted_at": null,\n
  "answers": [\n
    \n
      "id": 1,\n
      "question_id": 1,\n
      "label": "reponse1",\n
      "points": 3,\n
      "description": "",\n
      "created_at": "2017-08-29 08:54:45",\n
      "updated_at": "2017-08-29 08:54:45",\n
      "deleted_at": null\n
    ,\n
    \n
      "id": 2,\n
      "question_id": 1,\n
      "label": "reponse2",\n
      "points": 5,\n
      "description": "",\n
      "created_at": "2017-08-29 08:54:45",\n
      "updated_at": "2017-08-29 08:54:45",\n
      "deleted_at": null\n
    \n
  ]\n
\n
' matches JSON string "
  "survey_id": 1,
  "theme_id": 1,
  "pillar_id": 1,
  "name": "question",
  "type": "simple",
  "updated_at": "2017-08-29 08:54:45",
  "created_at": "2017-08-29 08:54:45",
  "id": 1,
  "answers": [
    
      "id": 1,
      "question_id": 1,
      "label": "reponse1",
      "points": 3,
      "description": "",
      "created_at": "2017-08-29 08:54:45",
      "updated_at": "2017-08-29 08:54:45",
      "deleted_at": null
    ,
    
      "id": 2,
      "question_id": 1,
      "label": "reponse2",
      "points": 5,
      "description": "",
      "created_at": "2017-08-29 08:54:45",
      "updated_at": "2017-08-29 08:54:45",
      "deleted_at": null
    
  ]

".
--- Expected
+++ Actual
@@ @@
 
-  "id": 1,
   "survey_id": 1,
   "theme_id": 1,
   "pillar_id": 1,
   "name": "question",
   "type": "simple",
+  "updated_at": "2017-08-29 08:54:45",
   "created_at": "2017-08-29 08:54:45",
-  "updated_at": "2017-08-29 08:54:45",
-  "deleted_at": null,
+  "id": 1,

你可以看到，实际上这两个 JSON 字符串并不相等，至少字段的顺序不一样。断言输出的问题在于它并没有真正的帮助，仅仅是因为断言只是比较了两个字符串。

assertEquals()

尽管如此，当我们 json_decode() 文件的内容然后使用 assertEquals() 断言时，如下所示：

use PHPUnit\Framework;

final class JsonTest extends Framework\TestCase

    public function testJsonEquals()
    
        $expected = json_decode(file_get_contents(__DIR__ . '/expected.json'), true);
        $actual = json_decode(file_get_contents(__DIR__ . '/actual.json'), true);

        $this->assertEquals($expected, $actual);
    

然后测试再次失败，但输出实际上更多更有帮助：

Failed asserting that two arrays are equal.
--- Expected
+++ Actual
@@ @@
-    'deleted_at' => null

如您所见，数据之间存在实际差异 - 根对象节点缺少值为 null 的 deleted_at 字段。

注意所以，问题归结为

您是否要断言两个 JSON 字符串相等或 你要断言两个JSON字符串表示的数据相等吗

根据哪个对您很重要，选择对您更有意义的断言。

【讨论】：

谢谢！ :) 最后，我将只使用 assertJson()，因为我只想确保控制器只返回一些特定的数据。