Manage the service status and start mode directly from Ruby code

Using the `keep_state` option of Yast2::SystemService#save method. See
commit 7acbe06.

src/include/dhcp-server/dialogs.rb

@@ -28,6 +28,7 @@ def initialize_dhcp_server_dialogs(include_target)
       Yast.import "Popup"
       Yast.import "Label"
       Yast.import "Confirm"
+      Yast.import "Mode"
 
       @functions = { :abort => fun_ref(method(:confirmAbort), "boolean ()") }
     end
@@ -88,7 +89,7 @@ def SaveAndRestart(event)
     #
     # @return [Boolean] true if settings are saved successfully; false otherwise
     def write_settings
-      DhcpServer.Write && dhcp_service.save
+      DhcpServer.Write && dhcp_service.save(keep_state: Mode.auto)
     end
 
     # Shows a popup asking to user if wants to change settings

src/modules/DhcpServer.pm

@@ -1746,36 +1746,6 @@ sub Write {
     SCR->Write (".sysconfig.dhcpd.DHCPD_OTHER_ARGS", $other_options);
     SCR->Write (".sysconfig.dhcpd", undef);
 
-    # TODO: Manage the service directly through Yast2::SystemService instead
-    if (Mode->auto() || Mode->config())
-    {
-        if ($start_service)
-        {
-        y2milestone ("Enabling the DHCP service");
-        my $ret = 1;
-        if (! $write_only)
-        {
-            $ret = Service->Restart ($SERVICE);
-        }
-        Service->Enable ($SERVICE);
-        if (!$ret)
-        {
-            # error report
-            Report->Error (__("Error occurred while restarting the DHCP daemon."));
-            $ok = 0;
-        }
-        }
-        else
-        {
-        y2milestone ("Disabling the DHCP service");
-        if (! $write_only)
-        {
-            Service->Stop ($SERVICE);
-        }
-        Service->Disable ($SERVICE);
-        }
-    }
-
     Progress->NextStage ();
 
     if ($dns_server_available) {

test/dialog_test.rb

@@ -0,0 +1,125 @@
+#!/usr/bin/env rspec
+# encoding: utf-8
+# Copyright (c) [2018] SUSE LLC
+#
+# All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of version 2 of the GNU General Public License as published
+# by the Free Software Foundation.
+#
+# This program 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 this program; if not, contact SUSE LLC.
+#
+# To contact SUSE LLC about this file by physical or electronic mail, you may
+# find current contact information at www.suse.com.
+
+require_relative "test_helper"
+
+require "yast2/system_service"
+require "cwm/service_widget"
+
+Yast.import "DhcpServer"
+
+describe "DhcpServerDialogsInclude" do
+  class TestDialog
+    include Yast::I18n
+    include Yast::UIShortcuts
+
+    def initialize
+      @HELPS = {}
+      Yast.include self, "dhcp-server/widgets.rb"
+      Yast.include self, "dhcp-server/dialogs.rb"
+    end
+  end
+
+  let(:widget) { instance_double(::CWM::ServiceWidget, cwm_definition: {}) }
+  let(:service) { instance_double(Yast2::SystemService, save: true, currently_active?: true) }
+
+  before do
+    allow_any_instance_of(TestDialog).to receive(:fun_ref)
+    allow(::CWM::ServiceWidget).to receive(:new).and_return(widget)
+    allow(Yast2::SystemService).to receive(:find).with("dhcpd").and_return(service)
+  end
+
+  describe "#WriteDialog" do
+    subject(:dialog) { TestDialog.new }
+
+    let(:dhcp_configuration_written) { true }
+
+    before do
+      allow(Yast::DhcpServer).to receive(:Write).and_return(dhcp_configuration_written)
+    end
+
+    it "writes needed configuration" do
+      expect(Yast::DhcpServer).to receive(:Write)
+
+      dialog.WriteDialog
+    end
+
+    context "when configuration is written" do
+      it "saves the system service" do
+        expect(service).to receive(:save)
+
+        dialog.WriteDialog
+      end
+
+      it "returns :next" do
+        expect(dialog.WriteDialog).to eq(:next)
+      end
+
+      context "and is in `auto` Mode" do
+        before do 
+          allow(Yast::Mode).to receive(:auto).and_return(true)
+        end
+
+        it "keeps current system status" do
+          expect(service).to receive(:save).with(hash_including(keep_state: true))
+
+          dialog.WriteDialog
+        end
+      end
+    end
+
+    context "when the configuration is not written" do
+      before do
+        allow(Yast2::Popup).to receive(:show).and_return(change_settings)
+      end
+
+      let(:change_settings) { :yes }
+      let(:dhcp_configuration_written) { false }
+
+      it "does not save the system service" do
+        expect(service).to_not receive(:save)
+
+        dialog.WriteDialog
+      end
+
+      it "aks for changing the current settings" do
+        expect(Yast2::Popup).to receive(:show)
+          .with(instance_of(String), hash_including(buttons: :yes_no))
+
+        dialog.WriteDialog
+      end
+
+      context "and user decides to change the current setting" do
+        it "returns :back" do
+          expect(dialog.WriteDialog).to eq(:back)
+        end
+      end
+
+      context "and user decides to cancel" do
+        let(:change_settings) { :no }
+
+        it "returns :abort" do
+          expect(subject.WriteDialog).to eq(:abort)
+        end
+      end
+    end
+  end
+end