Is there an easy way to stub out time.Now() globally during test?

Question

Part of our code is time sensitive and we need to able to reserve something and then release it in 30-60 seconds etc, which we can just do a time.Sleep(60 * time.Secon

Answer 1

I use the bouk/monkey package to replace the time.Now() calls in my code with a fake:

package main

import (
    "fmt"
    "time"

    "github.com/bouk/monkey"
)

func main() {
    wayback := time.Date(1974, time.May, 19, 1, 2, 3, 4, time.UTC)
    patch := monkey.Patch(time.Now, func() time.Time { return wayback })
    defer patch.Unpatch()
    fmt.Printf("It is now %s\n", time.Now())
}

This works well in tests to fake out system dependencies and avoids the abused DI pattern. Production code stays separate from test code and you gain useful control of system dependencies.