How to get different UUID each time a test is run in golang?

Question

I've got an integration test that requires a different UUID each time its run but the following code generates the same uuid each time.

package service

import (
    "fmt"
    "testing"

    "github.com/google/uuid"
)

func TestOne(t *testing.T) {
    id, _ := uuid.NewRandom()
    fmt.Println(id)
}

Here is similar code in the Go Playground: https://play.golang.org/p/85yecbn4F80

How do I get this to return a new value with every execution?

Answer 1

Edit from June 21 2022: the scripts do not seem to be cached anymore when using https://go.dev/play/. A new UUID is printed on each run, even when the script remains the same.

---

As users pointed out in the comments, the output in the Go playground is cached. If one tries this on their own command-line, a new UUID is printed on each run.

package main

import (
    "fmt"

    "github.com/google/uuid"
)

func main() {
    id, _ := uuid.NewRandom()
    fmt.Println(id)
}

And

$ go run .
604f5ea8-d146-4aac-9a15-4dc33a84eb59
$ go run .
3bc094cf-99c8-4250-98a0-9831fdadedac
$ go run .
b0c13db3-e466-4b5c-a179-e0a16469f11a

---

For what it's worth, one can invalidate the Go playground cache by changing the script (e.g., add or modify a comment). This will cause a new UUID to be generated.