Add termination package

Author: hioki-daichi

kadai3-2/hioki-daichi/termination/termination.go

@@ -0,0 +1,42 @@
+/*
+Package termination deals with Ctrl+C termination.
+*/
+package termination
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+var cleanFns []func()
+
+// for testing
+var osExit = os.Exit
+
+// Listen listens signals.
+func Listen(ctx context.Context, w io.Writer) (context.Context, func()) {
+	ctx, cancel := context.WithCancel(ctx)
+
+	ch := make(chan os.Signal, 2)
+	signal.Notify(ch, os.Interrupt, syscall.SIGTERM)
+	go func() {
+		<-ch
+		fmt.Fprintln(w, "\rCtrl+C pressed in Terminal")
+		cancel()
+		for _, f := range cleanFns {
+			f()
+		}
+		osExit(0)
+	}()
+
+	return ctx, cancel
+}
+
+// CleanFunc registers clean function.
+func CleanFunc(f func()) {
+	cleanFns = append(cleanFns, f)
+}

kadai3-2/hioki-daichi/termination/termination_test.go

@@ -0,0 +1,36 @@
+package termination
+
+import (
+	"context"
+	"io/ioutil"
+	"os"
+	"testing"
+	"time"
+)
+
+func TestTermination_Listen(t *testing.T) {
+	CleanFunc(func() {})
+
+	doneCh := make(chan struct{})
+	osExit = func(code int) { doneCh <- struct{}{} }
+
+	_, clean := Listen(context.Background(), ioutil.Discard)
+	defer clean()
+
+	proc, err := os.FindProcess(os.Getpid())
+	if err != nil {
+		t.Fatalf("err %s", err)
+	}
+
+	err = proc.Signal(os.Interrupt)
+	if err != nil {
+		t.Fatalf("err %s", err)
+	}
+
+	select {
+	case <-doneCh:
+		return
+	case <-time.After(100 * time.Millisecond):
+		t.Fatal("timeout")
+	}
+}