Mock for a builder interface

[mesirendon]

Hi everyone, I'd like to know what's the best way to mock a builder.

Let me setup the example:

package repository

type (
  myBuilder interface {
    Set() myBuilder
  }

  MyRepo struct {
    builder myBuilder
  }
)

func NewMyRepo(builder myBuilder) *MyRepo {
  return &MyRepo { builder: builder }
}

func(r *MyRepo) DoSomething() error {
  b := r.builder.Set()
  ...
  return nil
}

On the other hand I have my .mockery.yaml file defining the mockery output as:

disable-version-string: True
with-expecter: True
packages:
  github.com/mesirendon/mydomain/go/module/internal/repository:
    config:
      all: True
      outpkg: "mock"
      dir: "{{.InterfaceDir}}/mock"
      filename: "{{.InterfaceName}}_mock.go"

I'm having problems as the types don't match.

In the meantime, I can reduce my coverage by not testing the injection of the actual builder. But it would be nice to have everything tested.

Please point me in the right direction.

[LandonTClipp]

Can you show the errors you get when testing with the mock? Does mockery correctly set myBuilder as the return type to Set()?

[mesirendon]

Sure...

[mesirendon]

I'm also thinking that it might be better if I change my approach as I don't want to expose mocks publicly.

So the mock files could be something like mock_{{FileName}}_test.go and also defining the mocks as private. Maybe that could help me to solve the problem.

What do you think?

[LandonTClipp]

I'm pretty sure what's happening here is that your mocks are living in a separate package yet trying to use an unexported type (myBuilder) from your original package. This can't work. This is why I generally recommend people generate mocks in the same package.

As far as not exposing them publicly, yes you can append _test to the filename, or use build tags such that the mocks are generated only when you have a test tag specified.

[mesirendon]

First, you are right. I'm generating mocks in a folder called mocks. Thus, their package is mock.
Second, thanks. I didn't think about using test tagging. I'll explore that alternative.

Let me come up with the experiment and I'll let you know how it went.

[mesirendon]

I appreciate your help @LandonTClipp. I successfully managed to implement my mocker with your guidance. 👏🏽