GODT-1143 Turn off SMTP server while no connection

internal/smtp/server_test.go

@@ -0,0 +1,65 @@
+// Copyright (c) 2021 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package smtp
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/ProtonMail/proton-bridge/internal/bridge"
+	"github.com/ProtonMail/proton-bridge/internal/events"
+	"github.com/ProtonMail/proton-bridge/pkg/listener"
+	"github.com/ProtonMail/proton-bridge/pkg/ports"
+	goSMTP "github.com/emersion/go-smtp"
+
+	"github.com/stretchr/testify/require"
+)
+
+type testPanicHandler struct{}
+
+func (ph *testPanicHandler) HandlePanic() {}
+
+func TestSMTPServerTurnOffAndOnAgain(t *testing.T) {
+	panicHandler := &testPanicHandler{}
+
+	eventListener := listener.New()
+
+	port := ports.FindFreePortFrom(12345)
+	server := goSMTP.NewServer(nil)
+	server.Addr = fmt.Sprintf("%v:%v", bridge.Host, port)
+
+	s := &smtpServer{
+		panicHandler:  panicHandler,
+		server:        server,
+		eventListener: eventListener,
+	}
+	s.isRunning.Store(false)
+
+	go s.ListenAndServe()
+	time.Sleep(5 * time.Second)
+	require.False(t, ports.IsPortFree(port))
+
+	eventListener.Emit(events.InternetOffEvent, "")
+	time.Sleep(10 * time.Second)
+	require.True(t, ports.IsPortFree(port))
+
+	eventListener.Emit(events.InternetOnEvent, "")
+	time.Sleep(10 * time.Second)
+	require.False(t, ports.IsPortFree(port))
+}