MM-47171 Export direct channel favorites (#21570)

app/export.go

@@ -626,7 +626,12 @@ func (a *App) exportAllDirectChannels(writer io.Writer) *model.AppError {
 				continue
 			}
 
-			channelLine := ImportLineFromDirectChannel(channel)
+			favoritedBy, err := a.buildFavoritedByList(channel.Id)
+			if err != nil {
+				return err
+			}
+
+			channelLine := ImportLineFromDirectChannel(channel, favoritedBy)
 			if err := a.exportWriteLine(writer, channelLine); err != nil {
 				return err
 			}
@@ -636,6 +641,29 @@ func (a *App) exportAllDirectChannels(writer io.Writer) *model.AppError {
 	return nil
 }
 
+func (a *App) buildFavoritedByList(channelID string) ([]string, *model.AppError) {
+	prefs, err := a.Srv().Store().Preference().GetCategoryAndName(model.PreferenceCategoryFavoriteChannel, channelID)
+	if err != nil {
+		return nil, model.NewAppError("buildFavoritedByList", "app.preference.get_category.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+	}
+
+	userIDs := make([]string, 0, len(prefs))
+	for _, pref := range prefs {
+		if pref.Value != "true" {
+			continue
+		}
+
+		user, err := a.Srv().Store().User().Get(context.Background(), pref.UserId)
+		if err != nil {
+			return nil, model.NewAppError("buildFavoritedByList", "app.user.get.app_error", nil, "", http.StatusInternalServerError).Wrap(err)
+		}
+
+		userIDs = append(userIDs, user.Username)
+	}
+
+	return userIDs, nil
+}
+
 func (a *App) exportAllDirectPosts(ctx request.CTX, writer io.Writer, withAttachments bool) ([]imports.AttachmentImportData, *model.AppError) {
 	var attachments []imports.AttachmentImportData
 	afterId := strings.Repeat("0", 26)

app/export_converters.go

@@ -39,18 +39,25 @@ func ImportLineFromChannel(channel *model.ChannelForExport) *imports.LineImportD
 	}
 }
 
-func ImportLineFromDirectChannel(channel *model.DirectChannelForExport) *imports.LineImportData {
+func ImportLineFromDirectChannel(channel *model.DirectChannelForExport, favoritedBy []string) *imports.LineImportData {
 	channelMembers := *channel.Members
 	if len(channelMembers) == 1 {
 		channelMembers = []string{channelMembers[0], channelMembers[0]}
 	}
-	return &imports.LineImportData{
+
+	line := &imports.LineImportData{
 		Type: "direct_channel",
 		DirectChannel: &imports.DirectChannelImportData{
 			Header:  &channel.Header,
 			Members: &channelMembers,
 		},
 	}
+
+	if len(favoritedBy) != 0 {
+		line.DirectChannel.FavoritedBy = &favoritedBy
+	}
+
+	return line
 }
 
 func ImportLineFromUser(user *model.User, exportedPrefs map[string]*string) *imports.LineImportData {

app/export_test.go

@@ -223,7 +223,16 @@ func TestExportDMChannel(t *testing.T) {
 		defer th1.TearDown()
 
 		// DM Channel
-		th1.CreateDmChannel(th1.BasicUser2)
+		ch := th1.CreateDmChannel(th1.BasicUser2)
+
+		th1.App.Srv().Store().Preference().Save(model.Preferences{
+			{
+				UserId:   th1.BasicUser2.Id,
+				Category: model.PreferenceCategoryFavoriteChannel,
+				Name:     ch.Id,
+				Value:    "true",
+			},
+		})
 
 		var b bytes.Buffer
 		err := th1.App.BulkExport(th1.Context, &b, "somePath", model.BulkExportOpts{})
@@ -250,6 +259,12 @@ func TestExportDMChannel(t *testing.T) {
 		require.NoError(t, nErr)
 		require.Equal(t, 1, len(channels))
 		assert.ElementsMatch(t, []string{th1.BasicUser.Username, th1.BasicUser2.Username}, *channels[0].Members)
+
+		// Ensure the favorited channel was retained
+		fav, nErr := th2.App.Srv().Store().Preference().Get(th2.BasicUser2.Id, model.PreferenceCategoryFavoriteChannel, channels[0].Id)
+		require.NoError(t, nErr)
+		require.NotNil(t, fav)
+		require.Equal(t, "true", fav.Value)
 	})
 
 	t.Run("Invalid DM channel export", func(t *testing.T) {