added test files

internal/infrastructure/os/signal_test.go

@@ -0,0 +1,38 @@
+package os
+
+import (
+	"context"
+	"os"
+	"syscall"
+	"testing"
+	"time"
+
+	"go.uber.org/zap"
+)
+
+func TestSignalListener_CancelsOnSIGTERM(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	canceled := make(chan struct{})
+	go func() {
+		<-ctx.Done()
+		close(canceled)
+	}()
+
+	SignalListener(zap.NewNop(), cancel)
+
+	proc, err := os.FindProcess(os.Getpid())
+	if err != nil {
+		t.Fatalf("FindProcess: %v", err)
+	}
+	if err := proc.Signal(syscall.SIGTERM); err != nil {
+		t.Fatalf("Signal SIGTERM: %v", err)
+	}
+
+	select {
+	case <-canceled:
+	case <-time.After(2 * time.Second):
+		t.Fatal("context was not canceled after SIGTERM")
+	}
+}