Not able to stub static function

[rishavbhowmik]

Hi, I am new to GoLang, please pardon me in case this issue turns out to be lame.

Here is what I tried

import (
	"bytes"
	"testing"

	"github.com/prashantv/gostub"
)

// The function to stub
func RandomBytes(l uint8) ([]byte, error) {
	return []byte{1, 2, 3, 4}, nil
}

// The function to test
func PasswordHash(password string) ([]byte, error) {
	return RandomBytes(4)
}

// Test
func TestPasswordHash(t *testing.T) {
	var functionPtr = RandomBytes
	defer gostub.Stub(&functionPtr, func(l uint8) ([]byte, error) {
                println("Stub takes over") // This is never executed
		return []byte{5, 5, 5, 5}, nil
	}).Reset()

	hash, _ := PasswordHash("pass")
	if bytes.Compare(hash, []byte{5, 5, 5, 5}) != 0 {
		t.Error("Hash differs, stub didn't work. RandomSalt=", hash) // Test fails!
	}
}

So basically I am unable to stub the RandomBytes function.

Reproduced in playground

[prashantv]

gostub cannot stub static functions, it can only stub variables.

The typical usage is something like:

// Variable for stubbing
var randomBytesFunc = RandomBytes

func PasswordHash(password string) ([]byte, error) {
	// Use the variable for calling the function
	return randomBytesFunc(4)
}

And then gostub.Stub(&randomBytesFunc, ...) would replace the variable.