如何在RequireJS中模拟单元测试的依赖项？ [英] How can I mock dependencies for unit testing in RequireJS?

问题描述

我有一个我想要测试的AMD模块，但我想模拟它的依赖项，而不是加载实际的依赖项。我正在使用requirejs，我的模块的代码如下所示：

I have an AMD module I want to test, but I want to mock out its dependencies instead of loading the actual dependencies. I am using requirejs, and the code for my module looks something like this:

define(['hurp', 'durp'], function(Hurp, Durp) {
  return {
    foo: function () {
      console.log(Hurp.beans)
    },
    bar: function () {
      console.log(Durp.beans)
    }
  }
}

如何模拟 hurp 和 durp 这样我才能有效地进行单元测试？

How can I mock out hurp and durp so I can effectively unit test?

推荐答案

所以在阅读这篇文章我想出了一个解决方案，它使用requirejs配置函数为你的测试创建一个新的上下文，你可以简单地模拟你的依赖项：

So after reading this post I came up with a solution that use the requirejs config function to create a new context for your test where you can simply mock your dependencies:

var cnt = 0;
function createContext(stubs) {
  cnt++;
  var map = {};

  var i18n = stubs.i18n;
  stubs.i18n = {
    load: sinon.spy(function(name, req, onLoad) {
      onLoad(i18n);
    })
  };

  _.each(stubs, function(value, key) {
    var stubName = 'stub' + key + cnt;

    map[key] = stubName;

    define(stubName, function() {
      return value;
    });
  });

  return require.config({
    context: "context_" + cnt,
    map: {
      "*": map
    },
    baseUrl: 'js/cfe/app/'
  });
}

因此它会创建一个新的上下文，其中的定义Hurp 和 Durp 将由您传递给函数的对象设置。这个名字的Math.random可能有点脏，但它有效。因为如果你有一堆测试，你需要为每个套件创建新的上下文，以防止重用你的模拟，或者当你想要真正的requirejs模块时加载模拟。

So it creates a new context where the definitions for Hurp and Durp will be set by the objects you passed into the function. The Math.random for the name is maybe a bit dirty but it works. Cause if you'll have a bunch of test you need to create new context for every suite to prevent reusing your mocks, or to load mocks when you want the real requirejs module.

在你的情况下，它看起来像这样：

In your case it would look like this:

(function () {

  var stubs =  {
    hurp: 'hurp',
    durp: 'durp'
  };
  var context = createContext(stubs);

  context(['yourModuleName'], function (yourModule) {

    //your normal jasmine test starts here

    describe("yourModuleName", function () {
      it('should log', function(){
         spyOn(console, 'log');
         yourModule.foo();

         expect(console.log).toHasBeenCalledWith('hurp');
      })
    });
  });
})();

所以我在生产中使用这种方法已经有一段时间了，而且非常强大。

So I'm using this approach in production for a while and its really robust.

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