main.go

package main

import (
	"fmt"
	"time"
)

var chan1 = make(chan string)
var chan2 = make(chan string)

func main() {
	fmt.Println(channelMagic(1, 0))
	fmt.Println(channelMagic(0, 1))
	fmt.Println(channelMagic(1, 1))
}

func channelMagic(sleepOne int, sleepTwo int) string {
	go func() {
		time.Sleep(time.Duration(sleepOne) * time.Second)
		chan1 <- "I made it to channel one!"
	}()

	go func() {
		time.Sleep(time.Duration(sleepTwo) * time.Second)
		chan2 <- "I made it to channel two!"
	}()

	time.Sleep(time.Duration(10) * time.Millisecond)

	select {
	case v := <-chan1:
		return v
	case v := <-chan2:
		return v
	default:
		return "Nothing from the channels"
	}
}

main_test.go

package main

import "testing"

func Test_channelMagic(t *testing.T) {
	type args struct {
		sleepOne int
		sleepTwo int
	}
	tests := []struct {
		name string
		args args
		want string
	}{
		{
			name: "First Channel",
			args: args{0, 1},
			want: "I made it to channel one!",
		},
		{
			name: "Second Channel",
			args: args{1, 0},
			want: "I made it to channel two!",
		},
		{
			name: "No Channels",
			args: args{1, 1},
			want: "Nothing from the channels",
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := channelMagic(tt.args.sleepOne, tt.args.sleepTwo); got != tt.want {
				t.Errorf("channelMagic() = %v, want %v", got, tt.want)
			}
		})
	}
}