Angular & Jasmine：如何测试 $q 承诺链是否已解析

Question

我有一个公开函数的服务，该函数接收已解析的 CSV（使用 papaparse）并承诺反映解析状态：
如果文件缺少必填字段，承诺将被拒绝
否则，它将每一行解析为一个项目并自动填充缺失的字段（自动填充过程是异步的）。
当 all 项目被填充时，该函数使用项目数组

解析承诺

我要测试的函数是onCsvParse:

angular.module('csvParser', [])
  .factory('csvParser', ['$http',
    function($http) {
      var service = {
        onCsvParse: function(results, creatingBulkItems) {
          var errors = this.getCsvErrors(results);
          if (errors.length > 0) {
            //reject
            creatingBulkItems.reject(errors);
          } else {

            var items = this.parseCsv(results);
            var autoPopulateItems = [],
              populatedItems = [];
            for (var i = 0; i < populatedItems.length; i++) {
              var item = items[i];
              if (item.name === "" /*or some any field is missing */ ) {
                // auto populate item
                autoPopulateItems.push(this.autoPopulateItem(item));
              } else {
                var populatedItem = $q.when(item);
                populatedItems.push(populatedItem);
              }
            }
            populatedItems =autoPopulateItems.concat(populatedItems);
            var populatingAllItems = $q.all(populatedItems);
            populatingAllItems.then(function(items) {
              creatingBulkItems.resolve(items);
            }, function(err) {
              creatingBulkItems.resolve(err);
            });
          }
        },
        autoPopulateItem: function(newItem) {
          var populatingItem = $q.defer();
          var item = angular.copy(newItem);
          $http.post('api/getItemData', { /*.....*/ })
            .success(function(response) {
              //----Populate item fields
              item.name = response.name;
              //....
              //resolve the promise
              populatingItem.resolve(item)

            }).error(err) {
              // resolving on error for $q.all indication
              populatingItem.resolve(item)
            };
          return populatingItem.promise;

        }
      }
      return service;
    }
  ])

我对该方法的测试如下（简化）：

describe('bulk items upload test', function() {
  //upload csv & test scenarios...
  var $rootScope, $q, csvResults = {};
  var $httpBackend, requestHandler;
  beforeEach(module('csvParser'));

  beforeEach(inject(function(_$rootScope_, _$q_) {
    $rootScope = _$rootScope_;
    $q = _$q_;
  }));
  beforeEach(inject(function($injector) {
    // Set up the mock http service responses
    $httpBackend = $injector.get('$httpBackend');
    // backend definition common for all tests
    requestHandler = $httpBackend.when('POST', 'api/getItemData')
      .respond({
        name: "name",
        description: "description",
        imageUrl: "www.google.com"

      });


    //   afterEach(function(){ $rootScope.$apply();});

  }));
  it('Should parse csv string', function(done) {
    var csvString = "Name,Description of the page";//...

    Papa.parse(csvString, {
      complete: function(results) {
        csvResults = results;
        done();
      }
    });

  });
  it('Should fail', function(done) {
    var creatingBulkItems = $q.defer();
    console.log("here..");
    csvParser.onCsvParse(csvResults, creatingBulkItems);
    creatingBulkItems.promise.then(function() {
      console.log("1here..");
      //promise is never resolved
      expect(1).toEqual(1);
      done();
    }, function() {
      //promise is never rejeceted
      console.log("2here..");
      expect(1).toEqual(1);
      done();
    });
    $rootScope.$apply();

  });

});

有了这个，我得到了错误：错误：超时 - 异步回调未在 jasmine.DEFAULT_TIMEOUT_INTERVAL 指定的超时内调用。

尽管我调用了 $rootScope.$apply() 并且我也没有调用真正的异步调用（只有模拟，$q.all 除外），但承诺没有得到解决。我怎样才能让它发挥作用？

Answer 1

语法无效。您需要将函数传递给 error 回调。

        }).error(function(err) {
          // resolving on error for $q.all indication
          populatingItem.resolve(item)
        });
      return populatingItem.promise;

此外，您的 jasime 测试需要更多的初始化： http://plnkr.co/edit/wjykvpwtRA0kBBh3LcX3?p=preview

Answer 2

看完这篇文章后：https://gist.github.com/domenic/3889970我发现了我的问题。
关键点是使用 promise.then return 值来展平承诺链。

This [promise.then] function should return a new promise that is fulfilled when the given fulfilledHandler or errorHandler callback is finished. This allows promise operations to be chained together. The value returned from the callback handler is the fulfillment value for the returned promise. If the callback throws an error, the returned promise will be moved to failed state.

不是在内部承诺 success/fail 回调中解决外部承诺，而是在内部 promise.then 回调中解决外部承诺

所以我的修复是这样的：

onCsvParse: function(results) {
      var errors = this.getCsvErrors(results);
      if (errors.length > 0) {
         var deferred = $q.defer();
        //reject
        return deferred.reject(errors);
      } else {

        var items = this.parseCsv(results);
        var autoPopulateItems = [],
          populatedItems = [];
        for (var i = 0; i < populatedItems.length; i++) {
          var item = items[i];
          if (item.name === "" /*or some any field is missing */ ) {
            // auto populate item
            autoPopulateItems.push(this.autoPopulateItem(item));
          } else {
            var populatedItem = $q.when(item);
            populatedItems.push(populatedItem);
          }
        }
        populatedItems = autoPopulateItems.concat(populatedItems);
        var populatingAllItems = $q.all(populatedItems);
        return populatingAllItems.then(function(items) {
            return items;
        }, function(err) {
          return err;
        });
      }
    },

测试代码：

it('Should not fail :)', function(done) {
csvParser.onCsvParse(csvResults).then(function(items) {
  //promise is resolved
  expect(items).not.toBeNull();
  done();
}, function() {
  //promise is rejeceted
  //expect(1).toEqual(1);
  done();
});
$rootScope.$apply();});

Angular & Jasmine：如何测试 $q 承诺链是否已解析

Angular & Jasmine: how to test that a $q promise chain was resolved

promise

jasmine

angularjs

angular-promise