如何在 angularjs 中测试指令加载与否

Question

我已经编写了指令，该指令在参数中采用指令名称并将该指令动态加载为休闲：

.directive("loadDirective", function($compile, $timeout) {
        return {
            restrict: 'E',
            scope: {
                Dtype: '=type',
                subType: '@',
                data: "=data"
            },
            link: function(scope, element) {
                scope.$watch('Dtype', function() {
                    $timeout(function() {
                        var generatedTemplate = '<div ' + scope.Dtype + (scope.subType ? '-' + scope.subType + '-directive' : '-directive') + ' data="data" >dd</div>';
                        element.empty().append($compile(generatedTemplate)(scope));
                    })
                })
            },
        };
    })

这是我要动态加载的指令之一

.directive("dailyIntervalDirective", function() {
        return {
            scope: {
                data: '='
            },
            restrict: 'A',
            templateUrl: '/flat-ui/tpls/daily-interval.html'
        };
    })

现在我正在尝试为 loadDiretive 编写测试用例来测试它是否加载指令，如下所示：

describe("loadDirective directive", function() {
    var elm, scope;
    beforeEach(module('guideApp.directives'));
    beforeEach(module('/flat-ui/tpls/daily-interval.html'));
    beforeEach(angular.mock.inject(function($rootScope, $compile) {
        scope = $rootScope;
        elm = angular.element('<load-directive type="directive" sub-type="interval" data="schedulerData"></load-directive>');
        compile = $compile;
        compile(elm)(scope);
        scope.schedulerData = {
            interval: 1,
        }
        scope.$digest();
    }));
    it("should be able to load daily directive", function() {
        scope.directive = "daily";
        var intervaldirective = elm.find('div[daily-interval-directive]');
        expect(intervaldirective.length).toEqual(1);
    });
   });

这对我来说效果不佳。我尝试记录榆树，但它没有加载 dailyInterevalDirective。

Answer 1

您的 dailyIntervalDirective 似乎有 templateUrl.

现在，如果指令有效，那么在测试中，您可以期望 GET 调用 "/flat-ui/tpls/daily-interval.html" 使用 httpBackend 服务。因为一旦编译了 dailyIntervalDirective 指令，就应该加载该模板。希望能帮助到你。 :)

[编辑]
我也怀疑 elm.find('div[daily-interval-directive]'); 是否会起作用，正如 angular docs. 中提到的 find() - Limited to lookups by tag name

根据要求，请在下面找到示例代码片段：

// -----in your spec file----  
describe("loadDirective directive", function() {
var elm, scope,$httpBackend;
beforeEach(module('guideApp.directives'));
beforeEach(angular.mock.inject(function($rootScope, $compile,$httpBackend) {
    scope = $rootScope;
    $httpBackend= $httpBackend;
    $httpBackend.whenGET('/flat-ui/tpls/daily-interval.html').respond(200, 'any response you can send here, even a blank string, as it is just to test ');
    elm = angular.element('<load-directive type="directive" sub-type="interval" data="schedulerData"></load-directive>');
    compile = $compile;
    compile(elm)(scope);
    scope.schedulerData = {
        interval: 1,
    }
    scope.$digest();
}));
it("should try to load daily directive's template", function() {
    scope.directive = "daily";
    $httpBackend.expectGET('/flat-ui/tpls/daily-interval.html');
    $httpBackend.flush();
});
});

如果此测试用例通过，则表示指令已加载。

Answer 2

问题分为两部分。第一个问题是 指令定义对象 中的 templateUrl。正如@r_goyal 所回答的那样，只要通过 URL 加载模板，它就会通过 GET 调用加载。因此，您需要使用 httpBackend.

来模拟它

第二部分是$timeout的用法。 $timeout 异步执行，但测试同步执行。这就是您测试失败的原因。为了测试 $timeout 中的代码，我们使用 $timeout service found in angular.mock module 模拟它。我们需要在 mock $timeout 服务上使用 $timeout.flush 方法来强制原始 $timeout 中的代码同步执行。这是一个完全更正的示例：

describe("loadDirective directive", function() {
    var elm, scope, timeout, httpBackend;
    beforeEach(module('guideApp.directives'));
    beforeEach(module('/flat-ui/tpls/daily-interval.html'));
    beforeEach(angular.mock.inject(function($rootScope, $compile, $timeout, $httpBackend) {
        scope = $rootScope;
        timeout = $timeout;
        httpBackend = $httpBackend;

        elm = angular.element('<load-directive type="directive" sub-type="interval" data="schedulerData"></load-directive>');
        compile = $compile;
        compile(elm)(scope);
        scope.schedulerData = {
            interval: 1,
        }
        scope.$digest();
    }));
    it("should be able to load daily directive", function() {
        scope.directive = "daily";
        httpBackend.when('GET','/flat-ui/tpls/daily-interval.html').respond("<div> Any mock template or the original template loaded as a fixture </div>");

        scope.$apply();
        timeout.flush();
        httpBackend.flush();
        var intervaldirective = elm.find('div[daily-interval-directive]');
        expect(intervaldirective.length).toEqual(1);
    });
   });

有几点需要注意:

这里调用scope.$apply()作为加载指令的代码动态地在 watch 内。即使您将 Dtype 变量设置为范围为新值，watch 函数 将不会执行直到启动消化周期。
然后我们调用timeout.flush()强制$timeout中的代码为
同步执行

You can read more about testing $timeout here

希望对您有所帮助

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