模拟结构参数

Question

FULL DISCLOSURE: This is probably really dumb, but I'm new to Go and haven't used statically-typed languages in years.

I have a function that looks like this:

func Foo(bar *bar.BarStruct) {
  // do stuff with bar
}

In this example, bar is a third-party package and *bar.BarStruct is a pointer to a struct.

I would like to write a test for the Foo function while stubbing out bar.BarStruct struct. How would I stub out *bar.BarStruct?

In JavaScript for example, I would just do something like this

test('does a Foo', () => {
  const mockBarStruct = {
    someProp: 123
  }

  Foo(mockBarStruct)
  // rest of test
})

What's the equivalent way to stub a struct in Go?

Answer 1

If you had Foo take an interface instead of a struct pointer, the in tested you could pass a mock or fake struct that implements that interface.

There are some mocking libraries but because Golang doesn’t allow runtime type writing, they run compile-time and output code.

Hope that helps!