Mocking in Go

main.go

package main
import (
	"golang.org/x/net/context"
	"github.com/stretchr/testify/mock"
)

type Foo interface {
	Bar (ctx context.Context) (string)
}

type MockFoo struct{
	mock.Mock
	Foo
}

// Feels like it is mainly defining the signature
func (m MockFoo) Bar (ctx context.Context) (context.Context) {
//	args:= m.Called("test") // This says we can do mock.On("Bar", "test") <-- see (1) below
	args:= m.Called(mock.Anything) // This says we can do mock.On("Bar", _)
	return args.Get(0).(context.Context) // This says we can do mock.On(..).Return(something of type Context)
}

func main() {
	a := MockFoo{}
	//	a.On("Bar", "test").Return(context.TODO()) <-- This would have worked if we enabled the commented line above.
	a.On("Bar", context.TODO()).Return(context.TODO())
	a.Bar(context.TODO())
	println("OK")
}