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遍历对象并检查属性是否存在-Mocha / Chai

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我正在mocha / chai / NodeJs中设置一些单元测试。而且我正在测试在获取API调用中返回的response。

我的回复中有9个对象。我想检查一下，每个对象是否包含一个名为“ largeImageURL ”的属性。但是，正在努力做到这一点的最佳方法。

到目前为止，我已经在我的对象上使用.map来进行黑客攻击，该对象正在寻找largeImageURL，并返回每个值。并检查其中9个是否存在。

这有效并返回：

[ { largeImageURL: 'https://pixabay.com/get/55e3d3444a5ab108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/55e3d3474d57b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/50e6dd454b54b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/54e6dc4a4f50ac14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/57e7d244435aaa14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/53e6dc434351b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/52e0d2444a51b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/57e8d0404f57ae14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg' },{ largeImageURL: 'https://pixabay.com/get/57e8d0434b50a514f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg' } ]

但是我实际上想做这样的事情： 

expect(res.hits).to.have.key(largeImageURL);

但是我无法让expect以此方式工作。这可能吗？

这是我到目前为止写的，通过了：

describe('1) Check for succcessful fetech API call',() => {
it('a) Should return an object,with an array count of 9 elements',async () => {
    await fetch('https://pixabay.com/api/?key=MY_API_KEY&q=manhattan&image_type=photo&page=1&per_page=9')
        .then((res) => {
            return res.json()
        })
        .then((res) => {
            console.log(res.hits);
            expect(res).to.be.an('object');
            expect(res.hits).to.have.lengthOf(9);

            const imageURLs = res.hits.map(x => ({largeImageURL: x.largeImageURL}));
            expect(imageURLs).to.have.lengthOf(9);
        })
})

}）

Console.log通过这种方式生成此文件。任何想法将不胜感激！

  1) Check for succcessful fetech API call
[ { largeImageURL: 'https://pixabay.com/get/55e3d3444a5ab108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg',webformatHeight: 360,webformatWidth: 640,likes: 646,imageWidth: 2560,id: 336708,user_id: 242387,views: 302373,comments: 141,pageURL: 'https://pixabay.com/photos/manhattan-empire-state-building-336708/',imageHeight: 1440,webformatURL: 'https://pixabay.com/get/55e3d3444a5ab108f5d084609621317b133fd8e04e50744e762c79d2904fc1_640.jpg',type: 'photo',previewHeight: 84,tags: 'manhattan,empire state building,new york city',downloads: 141972,user: 'Free-Photos',favorites: 775,imageSize: 1587009,previewWidth: 150,userImageURL: 'https://cdn.pixabay.com/user/2014/05/07/00-10-34-2_250x250.jpg',previewURL: 'https://cdn.pixabay.com/photo/2014/05/03/01/04/manhattan-336708_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/55e3d3474d57b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg',webformatHeight: 426,likes: 775,imageWidth: 3000,id: 336475,views: 266538,comments: 110,pageURL: 'https://pixabay.com/photos/new-york-city-brooklyn-bridge-night-336475/',imageHeight: 2000,webformatURL: 'https://pixabay.com/get/55e3d3474d57b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_640.jpg',previewHeight: 99,tags: 'new york city,brooklyn bridge,night',downloads: 110902,favorites: 724,imageSize: 1230835,previewURL: 'https://cdn.pixabay.com/photo/2014/05/02/23/46/new-york-city-336475_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/50e6dd454b54b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg',likes: 443,imageWidth: 5184,id: 668616,user_id: 777390,views: 241940,comments: 72,pageURL: 'https://pixabay.com/photos/new-york-skyline-new-york-city-city-668616/',imageHeight: 3456,webformatURL: 'https://pixabay.com/get/50e6dd454b54b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_640.jpg',tags: 'new york,skyline,downloads: 84616,user: 'mpewny',favorites: 439,imageSize: 8661087,userImageURL: 'https://cdn.pixabay.com/user/2018/02/04/18-35-12-410_250x250.jpg',previewURL: 'https://cdn.pixabay.com/photo/2015/03/11/12/31/new-york-668616_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/54e6dc4a4f50ac14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg',likes: 351,imageWidth: 8256,id: 2699520,user_id: 4591426,views: 109012,comments: 35,pageURL: 'https://pixabay.com/photos/new-york-cityscape-night-city-2699520/',imageHeight: 5504,webformatURL: 'https://pixabay.com/get/54e6dc4a4f50ac14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_640.jpg',cityscape,downloads: 54675,user: 'igormattio',favorites: 332,imageSize: 11053173,userImageURL: '',previewURL: 'https://cdn.pixabay.com/photo/2017/08/31/05/36/new-york-2699520_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/57e7d244435aaa14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg',likes: 316,imageWidth: 4867,id: 1777986,user_id: 3628174,views: 80039,comments: 34,pageURL: 'https://pixabay.com/photos/usa-manhattan-contrasts-new-york-1777986/',imageHeight: 3246,webformatURL: 'https://pixabay.com/get/57e7d244435aaa14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_640.jpg',tags: 'usa,manhattan,contrasts',downloads: 42274,user: 'wiggijo',favorites: 384,imageSize: 5819085,userImageURL: 'https://cdn.pixabay.com/user/2016/10/28/09-04-12-659_250x250.jpeg',previewURL: 'https://cdn.pixabay.com/photo/2016/10/28/13/09/usa-1777986_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/53e6dc434351b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg',webformatHeight: 640,likes: 255,imageWidth: 2048,id: 569093,user_id: 364018,views: 98250,comments: 28,pageURL: 'https://pixabay.com/photos/city-manhattan-sunset-town-569093/',imageHeight: 2048,webformatURL: 'https://pixabay.com/get/53e6dc434351b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_640.jpg',previewHeight: 150,tags: 'city,sunset',downloads: 55895,user: 'Life-Of-Pix',favorites: 370,imageSize: 698912,userImageURL: 'https://cdn.pixabay.com/user/2014/08/21/23-01-42-554_250x250.jpg',previewURL: 'https://cdn.pixabay.com/photo/2014/12/15/13/57/city-569093_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/52e0d2444a51b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_1280.jpg',webformatHeight: 301,likes: 263,imageWidth: 5183,id: 407703,views: 100552,comments: 64,pageURL: 'https://pixabay.com/photos/manhattan-new-york-city-407703/',imageHeight: 2444,webformatURL: 'https://pixabay.com/get/52e0d2444a51b108f5d084609621317b133fd8e04e50744e762c79d2904fc1_640.jpg',previewHeight: 70,new york city,empire state building',downloads: 55127,favorites: 375,imageSize: 3543546,previewURL: 'https://cdn.pixabay.com/photo/2014/08/01/15/51/manhattan-407703_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/57e8d0404f57ae14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg',webformatHeight: 425,likes: 204,imageWidth: 4201,id: 1853552,user_id: 2286921,views: 64835,comments: 8,pageURL: 'https://pixabay.com/photos/architecture-new-york-city-manhattan-1853552/',imageHeight: 2790,webformatURL: 'https://pixabay.com/get/57e8d0404f57ae14f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_640.jpg',tags: 'architecture,manhattan',downloads: 36684,user: 'Pexels',favorites: 279,imageSize: 3935888,userImageURL: 'https://cdn.pixabay.com/user/2016/03/26/22-06-36-459_250x250.jpg',previewURL: 'https://cdn.pixabay.com/photo/2016/11/23/15/32/architecture-1853552_150.jpg' },{ largeImageURL: 'https://pixabay.com/get/57e8d0434b50a514f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_1280.jpg',likes: 145,imageWidth: 5000,id: 1850129,views: 59983,comments: 7,pageURL: 'https://pixabay.com/photos/architecture-new-york-city-manhattan-1850129/',imageHeight: 2813,webformatURL: 'https://pixabay.com/get/57e8d0434b50a514f6da8c7dda793e781039dee3564c704c722c78d6914ac75c_640.jpg',downloads: 34065,favorites: 258,imageSize: 3275708,previewURL: 'https://cdn.pixabay.com/photo/2016/11/22/19/17/architecture-1850129_150.jpg' } ]
    ✓ a) Should return an object,with an array count of 9 elements (196ms)
bbsliangjigang 回答：遍历对象并检查属性是否存在-Mocha / Chai

您可以使用插件chai-each

在下面的代码段中，我包含chaiEach作为浏览器功能

chai.use(chaiEach);
expect = chai.expect;
test = function(testName,expected) {
  try {
    expect(expected).each.have.property('foo');
    console.log(testName + " has sucsess");
  } catch(e) {
   console.log(testName + " fails with : " + e);
  }
};

test("Nominal case",[{foo:'bar'},{foo:'buzz'}]);
test("Error case",{bar:0},{foo:'buzz'}]);
<script src="https://cdnjs.cloudflare.com/ajax/libs/chai/4.2.0/chai.min.js"></script>
<script>chaiEach = function(chai,utils) {

  const propertyNames = Object.getOwnPropertyNames(chai.Assertion.prototype);

  const propertyDescs = {};
  for (const name of propertyNames) {
    propertyDescs[name] = Object.getOwnPropertyDescriptor(chai.Assertion.prototype,name);
  }

  const methodNames = propertyNames.filter(name => {
    return name !== "assert" && typeof propertyDescs[name].value === "function";
  });

  chai.Assertion.addProperty('each',function () {
    const each = utils.flag(this,'each') || 0;
    utils.flag(this,'each',each + 1);
  });

  methodNames.forEach(methodName => {
    chai.Assertion.overwriteMethod(methodName,function (_super) {
      return function assertEach () {
        if (utils.flag(this,'each')) {
          const each = utils.flag(this,'each');
          utils.flag(this,each - 1);
          var obj = this._obj;

          new chai.Assertion(obj).is.an.instanceOf(Array);
          obj.map(item => {
            const that = cloneAssertion(this);
            utils.flag(that,'object',item);
            _super.apply(that,arguments);
            return utils.flag(that,'object');
          });
      } else {
        _super.apply(this,arguments);
      }
    };
    });
  });

  function cloneAssertion(original) {
    const copy = Object.create(original);
    utils.transferFlags(original,copy,false);

    return copy;
  }
};</script>

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