Mock只是测试行为，确保调用了特定的方法。 Stub是特定对象的可测试版本(本质上)。

你说的苹果方式是什么意思?

他使用的通用术语是测试替身(想想特技替身)。Test Double是一个通用术语，用于为测试目的替换生产对象的任何情况。杰拉德列出了各种各样的替身:

Dummy objects are passed around but never actually used. Usually they are just used to fill parameter lists. Fake objects actually have working implementations, but usually take some shortcut which makes them not suitable for production (an InMemoryTestDatabase is a good example). Stubs provide canned answers to calls made during the test, usually not responding at all to anything outside what's programmed in for the test. Spies are stubs that also record some information based on how they were called. One form of this might be an email service that records how many messages it was sent(also called Partial Mock). Mocks are pre-programmed with expectations which form a specification of the calls they are expected to receive. They can throw an exception if they receive a call they don't expect and are checked during verification to ensure they got all the calls they were expecting.

源

非常清楚和实际:

Stub:实现要伪造的类/对象的方法的类或对象，并且总是返回你想要的东西。

JavaScript示例:

var Stub = {
   method_a: function(param_a, param_b){
      return 'This is an static result';
   }
}

Mock:与存根相同，但是它增加了一些逻辑，当一个方法被调用时“验证”，这样你就可以确定某个实现正在调用该方法。

正如@mLevan所说，假设你正在测试一个用户注册类。在调用Save之后，它应该调用SendConfirmationEmail。

一个非常愚蠢的代码

var Mock = {
   calls: {
      method_a: 0
   }

   method_a: function(param_a, param_b){
     this.method_a++; 
     console.log('Mock.method_a its been called!');
   }
}

模拟:帮助模拟和检查结果交互。这些交互 SUT调用它的依赖项来改变它们的状态。

存根:帮助模拟传入的交互。这些相互作用称为 SUT对其依赖项进行处理以获取输入数据。

来源:单元测试原则、实践和模式- Manning

存根和模拟都覆盖外部依赖项，但区别在于

stub ->用于测试数据

mock ->用于测试行为

不测试任何东西(只是用空方法覆盖功能，例如替换Logger以避免在测试时记录任何噪音)

在codeschool.com的课程《Rails僵尸测试》中，他们给出了这些术语的定义:

Stub

用于将方法替换为返回指定结果的代码。

Mock

带有调用方法的断言的存根。

因此，正如Sean Copenhaver在他的回答中所描述的那样，不同之处在于mock设置了期望(即做出断言，关于是否或如何调用它们)。