MM-10699: Disallow renaming direct and group message channels (#9518)

* MM-10699: Disallow renaming direct and group message channels

* Replacing errors.New with errors.Wrapf

app/channel.go

@@ -163,6 +163,14 @@ func (a *App) CreateChannelWithUser(channel *model.Channel, userId string) (*mod
 
 // RenameChannel is used to rename the channel Name and the DisplayName fields
 func (a *App) RenameChannel(channel *model.Channel, newChannelName string, newDisplayName string) (*model.Channel, *model.AppError) {
+	if channel.Type == model.CHANNEL_DIRECT {
+		return nil, model.NewAppError("RenameChannel", "api.channel.rename_channel.cant_rename_direct_messages.app_error", nil, "", http.StatusBadRequest)
+	}
+
+	if channel.Type == model.CHANNEL_GROUP {
+		return nil, model.NewAppError("RenameChannel", "api.channel.rename_channel.cant_rename_group_messages.app_error", nil, "", http.StatusBadRequest)
+	}
+
 	channel.Name = newChannelName
 	if newDisplayName != "" {
 		channel.DisplayName = newDisplayName

app/channel_test.go

@@ -640,12 +640,45 @@ func TestRenameChannel(t *testing.T) {
 	th := Setup().InitBasic()
 	defer th.TearDown()
 
-	channel := th.createChannel(th.BasicTeam, model.CHANNEL_OPEN)
-
-	channel, err := th.App.RenameChannel(channel, "newchannelname", "New Display Name")
-	if err != nil {
-		t.Fatal("Failed to update channel name. Error: " + err.Error())
+	testCases := []struct {
+		Name                string
+		Channel             *model.Channel
+		ExpectError         bool
+		ExpectedName        string
+		ExpectedDisplayName string
+	}{
+		{
+			"Rename open channel",
+			th.createChannel(th.BasicTeam, model.CHANNEL_OPEN),
+			false,
+			"newchannelname",
+			"New Display Name",
+		},
+		{
+			"Fail on rename direct message channel",
+			th.CreateDmChannel(th.BasicUser2),
+			true,
+			"",
+			"",
+		},
+		{
+			"Fail on rename direct message channel",
+			th.CreateGroupChannel(th.BasicUser2, th.CreateUser()),
+			true,
+			"",
+			"",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.Name, func(t *testing.T) {
+			channel, err := th.App.RenameChannel(tc.Channel, "newchannelname", "New Display Name")
+			if tc.ExpectError {
+				assert.NotNil(t, err)
+			} else {
+				assert.Equal(t, tc.ExpectedName, channel.Name)
+				assert.Equal(t, tc.ExpectedDisplayName, channel.DisplayName)
+			}
+		})
 	}
-	assert.Equal(t, "newchannelname", channel.Name)
-	assert.Equal(t, "New Display Name", channel.DisplayName)
 }