Bulk import/export supports direct messages from a user to themselves (#13200)

* Test added to check support for import of messages sent to your own DM
channel

* Support for single member direct channel messages and posts

Now bulk import is able to export/import the self direct channel and
the posts inside

* Improve how the copy of channel members for DM and DM posts

* Improved the tests for the export self-channels

app/export.go

@@ -532,12 +532,6 @@ func (a *App) ExportAllDirectChannels(writer io.Writer) *model.AppError {
 				continue
 			}
 
-			// There's no import support for single member channels yet.
-			if len(*channel.Members) == 1 {
-				mlog.Debug("Bulk export for direct channels containing a single member is not supported.")
-				continue
-			}
-
 			channelLine := ImportLineFromDirectChannel(channel)
 			if err := a.ExportWriteLine(writer, channelLine); err != nil {
 				return err
@@ -568,12 +562,6 @@ func (a *App) ExportAllDirectPosts(writer io.Writer) *model.AppError {
 				continue
 			}
 
-			// There's no import support for single member channels yet.
-			if len(*post.ChannelMembers) == 1 {
-				mlog.Debug("Bulk export for posts containing a single member is not supported.")
-				continue
-			}
-
 			// Do the Replies.
 			replies, err := a.buildPostReplies(post.Id)
 			if err != nil {

app/export_converters.go

@@ -39,11 +39,15 @@ func ImportLineFromChannel(channel *model.ChannelForExport) *LineImportData {
 }
 
 func ImportLineFromDirectChannel(channel *model.DirectChannelForExport) *LineImportData {
+	channelMembers := *channel.Members
+	if len(channelMembers) == 1 {
+		channelMembers = []string{channelMembers[0], channelMembers[0]}
+	}
 	return &LineImportData{
 		Type: "direct_channel",
 		DirectChannel: &DirectChannelImportData{
 			Header:  &channel.Header,
-			Members: channel.Members,
+			Members: &channelMembers,
 		},
 	}
 }
@@ -158,10 +162,14 @@ func ImportLineForPost(post *model.PostForExport) *LineImportData {
 }
 
 func ImportLineForDirectPost(post *model.DirectPostForExport) *LineImportData {
+	channelMembers := *post.ChannelMembers
+	if len(channelMembers) == 1 {
+		channelMembers = []string{channelMembers[0], channelMembers[0]}
+	}
 	return &LineImportData{
 		Type: "direct_post",
 		DirectPost: &DirectPostImportData{
-			ChannelMembers: post.ChannelMembers,
+			ChannelMembers: &channelMembers,
 			User:           &post.User,
 			Message:        &post.Message,
 			CreateAt:       &post.CreateAt,

app/export_test.go

@@ -284,10 +284,11 @@ func TestExportDMChannelToSelf(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, 0, i)
 
-	// Ensure no channels were imported
 	channels, err = th2.App.Srv.Store.Channel().GetAllDirectChannelsForExportAfter(1000, "00000000")
 	require.Nil(t, err)
-	assert.Equal(t, 0, len(channels))
+	assert.Equal(t, 1, len(channels))
+	assert.Equal(t, 1, len((*channels[0].Members)))
+	assert.Equal(t, th1.BasicUser.Username, (*channels[0].Members)[0])
 }
 
 func TestExportGMChannel(t *testing.T) {
@@ -478,5 +479,7 @@ func TestExportDMPostWithSelf(t *testing.T) {
 
 	posts, err = th2.App.Srv.Store.Post().GetDirectPostParentsForExportAfter(1000, "0000000")
 	require.Nil(t, err)
-	assert.Equal(t, 0, len(posts))
+	assert.Equal(t, 1, len(posts))
+	assert.Equal(t, 1, len((*posts[0].ChannelMembers)))
+	assert.Equal(t, th1.BasicUser.Username, (*posts[0].ChannelMembers)[0])
 }

app/import_test.go

@@ -163,8 +163,10 @@ func TestImportBulkImport(t *testing.T) {
 {"type": "user", "user": {"username": "` + username3 + `", "email": "` + username3 + `@example.com", "teams": [{"name": "` + teamName + `", "channels": [{"name": "` + channelName + `"}], "delete_at": 123456789016}]}}
 {"type": "post", "post": {"team": "` + teamName + `", "channel": "` + channelName + `", "user": "` + username + `", "message": "Hello World", "create_at": 123456789012, "attachments":[{"path": "` + testImage + `"}]}}
 {"type": "post", "post": {"team": "` + teamName + `", "channel": "` + channelName + `", "user": "` + username3 + `", "message": "Hey Everyone!", "create_at": 123456789013, "attachments":[{"path": "` + testImage + `"}]}}
+{"type": "direct_channel", "direct_channel": {"members": ["` + username + `", "` + username + `"]}}
 {"type": "direct_channel", "direct_channel": {"members": ["` + username + `", "` + username2 + `"]}}
 {"type": "direct_channel", "direct_channel": {"members": ["` + username + `", "` + username2 + `", "` + username3 + `"]}}
+{"type": "direct_post", "direct_post": {"channel_members": ["` + username + `", "` + username + `"], "user": "` + username + `", "message": "Hello Direct Channel to myself", "create_at": 123456789014}}
 {"type": "direct_post", "direct_post": {"channel_members": ["` + username + `", "` + username2 + `"], "user": "` + username + `", "message": "Hello Direct Channel", "create_at": 123456789014}}
 {"type": "direct_post", "direct_post": {"channel_members": ["` + username + `", "` + username2 + `", "` + username3 + `"], "user": "` + username + `", "message": "Hello Group Channel", "create_at": 123456789015}}
 {"type": "emoji", "emoji": {"name": "` + emojiName + `", "image": "` + testImage + `"}}`