Stubbing in Go (Golang)

stub.go

package main

import (
	"fmt"
	"reflect"
	"time"
)

func main() {
	stubPrototype := func(in []reflect.Value) []reflect.Value {
		return []reflect.Value{reflect.ValueOf(time.Now())}
	}

	makeStub := func(stubbed interface{}) interface{} {
		return reflect.MakeFunc(reflect.TypeOf(stubbed), stubPrototype).Interface()
	}

	timeStub := makeStub(time.Now).(func() time.Time)
	fmt.Println(timeStub())
}

Pretty awesome, but crazy!

This totally works when you run it in the standalone program, but it doesn't seem like stubbed time.Now actually gets called from prod code

webdev

Of course not. The point is only to make a stub that you can pass to verify that something got called.