Ask HN: How to approach testing in Golang?

    type Database interface {
        Users() ([]*User, error)
    }

    type MockDatabase struct {
        UsersStub func() ([]*User, error)
    }

    func (m MockDatabase) Users() ([]*User, error) {
        if m.UsersStub == nil {
            panic("MockDatabase.UsersStub is nil")
        }
        return (m.UsersStub)()
    }

    func TestSomething(t *testing.T) {
        db := MockDatabase{
            UsersStub: func() ([]*User, error) {
                ...
            }
        }

        // use db here
    }

    type Fooer interface {
       Do(int)int 
    }

    func Accept(f Fooer){
       f.Do(10)
    }

    type FooImpl struct {
      T testing.T
    }

    func(f FooImpl)Do(i int)int{
      f.T.Helper()
      if i!=10{
         f.T.Fail("i=10 expected")
      }
      return 0
    }

    // the test
    func TestAccept(t testing.T){
       Accept(FooImpl{T:t})
    }