go-os-signals

Motivation

Handling signals with go is simple and awesome. But, it has limitations when you want to implement tests for what should happen when an specific signal arrives at determined time.

This library tries not to change the Go logic for signals. Neither tries to be complex. It just wraps the signal behavior into a interface that can be mocked.

Usage

Below a pretty straightforward usage of the library.

package main

import (
	"fmt"
	"syscall"

	signals "github.com/jamillosantos/go-os-signals"
)

func main() {
	l := signals.NewListener(syscall.SIGINT, syscall.SIGTERM)

	fmt.Println("Running ... [hit ctrl+c to finish]")
	sig := <-l.Receive()
	fmt.Println("Signal:", sig)
}

If you need multiple goroutines to listen to the same signal you can either use multiple Listeners or a Waiter:

package main

import (
	"fmt"
	"sync"
	"syscall"

	signals "github.com/jamillosantos/go-os-signals"
)

func main() {
	var wg sync.WaitGroup
	wg.Add(2)

	l := signals.NewWaiter(syscall.SIGINT, syscall.SIGTERM)
	go func() {
		defer wg.Done()
		l.Wait()
		fmt.Println("From GOROUTINE 1")

	}()
	go func() {
		defer wg.Done()
		l.Wait()
		fmt.Println("From GOROUTINE 2")
	}()

	fmt.Println("Running ... [hit ctrl+c to finish]")
	l.Wait()
	fmt.Println("Signal received")
	wg.Wait() // Wait goroutines to finish
}

You can find more examples at the examples folder.

Testing

For testing, the "receiving" part of the code is EXACTLY the same. But, the MockListener has one more capability: Send.

package main

import (
	"fmt"
	"syscall"
	"time"

	"github.com/jamillosantos/go-os-signals/signaltest"
)

func main() {
	l := signaltest.NewMockListener(syscall.SIGINT, syscall.SIGTERM)

	go func() {
		time.Sleep(time.Second * 1)
		l.Send(syscall.SIGINT)
	}()

	fmt.Println("Running ... [wait 1 second]")
	sig := <-l.Receive()
	fmt.Println("Signal:", sig)
}

You can find more examples at the examples folder.