与茉莉花一起使用上下文

Question

我想使用茉莉花的上下文,所以我可以组织我的模拟返回.这是一些伪代码来演示我想要做的事情.我希望这两个期望都能通过:

describe('a module', function(){
    var whatTheFunctionReturns;
    beforeEach(function(){
        module('anApp', function($provide){
            $provide.value('aFactory', { aFunction: whatTheFunctionReturns })
        }
    });

    describe('when the function returns alpha', function(){
        whatTheFunctionReturns = 'alpha'

        it('should get data from a service', function(){
            expect(aFactory.aFunction).toEqual( 'alpha' )
        }); 
    });
    describe('when the function returns beta', function(){
        whatTheFunctionReturns = 'beta'

        it('should get data from a service', function(){
            expect(aFactory.aFunction).toEqual( 'beta' )
        }); 
    });
});

请仔细阅读以上内容.你看到我想做什么了吗？代码

$provide.value('aFactory', { aFunction: whatTheFunctionReturns })

在beforeEach块中写入一次,但变量

whatTheFunctionReturns

在两个描述的块中更改,when the function returns alpha并且when the function returns beta.

但是,它不起作用.这是一些真正的代码,我正在尝试测试控制器并模拟它依赖的工厂:

describe('firstController', function(){
    var $rootScope, $scope, $controller
    var message = 'I am message default'

    beforeEach(function(){
        module('App',function($provide){
            $provide.value('ServiceData', { message: message})
        });
        inject(function(_$rootScope_,_$controller_){
            $rootScope = _$rootScope_
            $scope = $rootScope.$new()
            $controller = _$controller_
            $controller('firstController', { '$rootScope' : $rootScope, '$scope' : $scope })
        });
    });

    describe('when message 1', function(){
        beforeEach(function(){
            message = 'I am message one'
        });
        it('should get data from a service', function(){
            expect($scope.serviceData.message).toEqual( '1' ) // using wrong data so I can see what data is being returned in the error message
        }); 
    });

    describe('when message 2', function(){
        beforeEach(function(){
            message = 'I am message two'
        });
        it('should get data from a service', function(){
            expect($scope.serviceData.message).toEqual( '2' ) // using wrong data so I can see what data is being returned in the error message
        });
    });
});

这是我收到的错误消息:

Firefox 34.0.0 (Ubuntu) firstController when message 1 should get data from a service FAILED
    Expected 'I am message default' to equal '1'.

Firefox 34.0.0 (Ubuntu) firstController when message 2 should get data from a service FAILED
    Expected 'I am message one' to equal '2'.

这是一半的工作.变量正在更新,但仅在最后一个描述块('when message 2')中.这是我期望返回的内容:

Firefox 34.0.0 (Ubuntu) firstController when message 1 should get data from a service FAILED
    Expected 'I am message one' to equal '1'.

Firefox 34.0.0 (Ubuntu) firstController when message 2 should get data from a service FAILED
    Expected 'I am message two' to equal '2'.

我怎样才能做到这一点？你看到我正在尝试用describe块做什么吗？

Answer 1

你误解了Jasmine在执行每个测试之前是如何构建测试用例的.

看看这个并执行它:

describe("Test", function(){
    console.info("Calling beforeEach() before describe()");
    beforeEach(function(){
        console.info("Running before()");
    });

    console.info("Calling describe() A");
    describe("describe A", function(){
        console.info("Calling it() A 0");

        it('should A 0', function(){
            console.info("Running it() A 1");
            expect("test to be").toBe("implemented");
        });

        console.info("Calling it() A 1");
        it('should A 1', function(){
            console.info("Running it() A 2");
            expect("test to be").toBe("implemented");
        });

        console.info("Calling it() A 2");
        it('should A 2', function(){
            console.info("Running it() A 3");
            expect("test to be").toBe("implemented");
        });
    });

});

在控制台中,您将观察到:

Calling beforeEach() before describe()
Calling describe() A
Calling it() A 0
Calling it() A 1
Calling it() A 2
Running before()
Running it() A 1
Running before()
Running it() A 2
Running before()
Running it() A 3

这里发生了什么？

当您调用describe()回调函数中的代码时,将执行您提供的代码.对其他describe()s的后续调用将执行其回调.每次调用it(),beforeEach()并将afterEach()在内部队列树中排队传递的回调,before将被添加到每个分支,after将被附加到该分支.然后队列被逐个移动,Jasmine将为每一步执行存储的回调.

当寻找到你的第一个代码,这意味着你的所有任务whatTheFunctionReturns被执行,则每个it()(由preceeded beforeEach())正在执行

你应该做什么:

describe('a module', function(){
    var whatTheFunctionReturns;

    // pepare to run in beforeEach()
    function _beforeModule(){
        module('anApp', function($provide){
            $provide.value('aFactory', { aFunction: whatTheFunctionReturns })
        }
    }

    describe('when the function returns alpha', function(){
        beforeEach(function(){
           whatTheFunctionReturns = 'alpha';
           _beforeModule();
        });

        it('should get data from a service', function(){
            expect(aFactory.aFunction).toEqual( 'alpha' )
        }); 
    });
    describe('when the function returns beta', function(){
        beforeEach(function(){
           whatTheFunctionReturns = 'beta';
           _beforeModule();
        });

        it('should get data from a service', function(){
            expect(aFactory.aFunction).toEqual( 'beta' )
        }); 
    });
});

您必须将赋值包装beforeEach()或it()块.