要模拟方法调用，您需要对结构进行模拟.

To mock a method call, you need to make a mock of your structure.

对于您提供的代码示例，我建议创建一个实现您的Perform调用的Performer接口.您的真实结构和模拟结构都将实现此接口.

With the code example you provided, I would recommend making a Performer interface that implements your Perform call. Both your real structure and your mock structure would implement this interface.

我还建议您将结构作为参数传递给invoke函数，而不要使用全局变量.

I would also recommend passing your structure as an argument to the invoke function instead of using a global variable.

这里是一个例子:

type Performer interface {
    perform()
}

type A struct {
}

func (a *A) perform() {
    fmt.Println("real method")
}

type AMock struct {
}

func (a *AMock) perform () {
    fmt.Println("mocked method")
}

func caller(p Performer) {
    p.perform()
}

在测试中，将模拟注入到invoke调用中. 在您的真实代码中，将真实结构注入您的invoke调用.

In your tests, inject the mock to your invoke call. In your real code, inject the real structure to your invoke call.

使用类似> https://godoc.org/github.com/stretchr的库/testify/mock ，您甚至还可以真正轻松地验证使用正确的参数(正确的次数)调用了您的方法，并控制了模拟的行为.

Using a library like https://godoc.org/github.com/stretchr/testify/mock you will even be able to really easily verify that your method is called with the right arguments, called the right amount of times, and control the mock's behavior.