我可以在回调中动态创建测试规范吗？ [英] Can I dynamically create a test spec within a callback?

问题描述

我想检索页面上的元素列表，并为每个元素创建一个测试规范。我的（伪）代码是： -

I want to retrieve a list of elements on a page, and for each one, create a test spec. My (pseudo) code is :-

fetchElements().then(element_list) {
   foreach element {
     it("should have some property", function() {
        expect("foo")
     })
   }
}

当我运行它时，我得到No specs found，我认为这是有意义的，因为它们是在主路径上定义的。

When I run this, I get "No specs found", which I guess makes sense since they are being defined off the main path.

实现动态创建规格的最佳方法是什么？

What's the best way to achieve dynamically created specs?

推荐答案

存在一些主要问题阻止它轻松实现：

There are major problems preventing it to be easily achieved:

• 您创建的规范基于异步代码的结果 - 关于元素量角器应该首先找到


• 你只能拥有 Protractor / WebDriverJS 具体代码在 it ， beforeEach ， beforeAll ， afterEach ， afterAll 以使其正常工作并将保证放在控制流等上。


• 你不能嵌套它 blocks - jasmine 不会执行它们： 无法在另一个'it'内执行'it'

• the specs you are creating are based on the result of asynchronous code - on the elements Protractor should first find
• you can only have the Protractor/WebDriverJS specific code inside the it, beforeEach, beforeAll, afterEach, afterAll for it to work properly and have the promises put on the Control Flow etc.
• you cannot have nested it blocks - jasmine would not execute them: Cannot perform a 'it' inside another 'it'

如果它不是你想要生成测试用例的元素，而是一个静态变量机智ha定义的值，它将如此简单：

If it were not the elements you want to generate test cases from, but a static variable with a defined value, it would be as simple as:

describe("Check something", function () {
    var arr = [
        {name: "Status Reason", inclusion: true},
        {name: "Status Reason", inclusion: false}
    ];

    arr.map(function(item) {
        it("should look good with item " + item, function () {
            // test smth
        });
    });
});

但是，如果 arr 将是一个承诺，测试将在一开始就失败，因为中的代码描述（不在 内）将被执行由jasmine加载测试。

But, if arr would be a promise, the test would fail at the very beginning since the code inside describe (which is not inside it) would be executed when the tests would be loaded by jasmine.

总而言之，只有一个 it（）阻止并在其中工作：

To conclude, have a single it() block and work inside it:

it("should have elements with a desired property", function() {
    fetchElements().then(element_list) {
        foreach element {
            expect("foo")
        })
    }
}

如果您担心将测试失败与元素区分开来，您可以，例如，提供可读的错误消息，以便在测试失败时，您可以轻松地说，哪些元素未通过测试（在您的伪测试用例中没有特定属性）。例如，您可以将自定义消息提供给 expect（） ：

If you are worried about distinguishing test failures from an element to element, you can, for instance, provide readable error messages so that, if a test fails, you can easily say, which of the elements has not passed the test (did not have a specific property in your pseudo-test case). For example, you can provide custom messages to expect():

expect(1).toEqual(2, 'because of stuff') 

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