Delete comment - Deleted comment is not synchronized between other clients

[dklymenk]

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Expected Result:

Deleting a comment should delete it on other participants' screens too

Actual Result:

Deleting a comment doesn't cause any visible update on any other client with chat open.

Action Performed:

1. Login into account A on 2 devices. (or tabs/browsers that don't share local storage)
2. Login into account B on another devices or incognito window.
3. Send a message from account A to account B.
4. You will see it on both second screen for account A and screen for account B.
5. Delete the message you've just sent as account A.
6. The message will still be on both second screen for account A and screen for account B.

Workaround:

Page refresh doesn't help. Only workaround is deleting the local storage entry for the chat or wiping it completely, forcing it to reload entire chat history.

Platform:

Where is this issue occurring?

Web
iOS
Android
Desktop App
Mobile Web

Version Number: 1.0.65-0
Logs: https://stackoverflow.com/c/expensify/questions/4856
Notes/Photos/Videos:

new_issue_cut.mp4

Expensify/Expensify Issue URL:

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[MelvinBot]

Triggered auto assignment to @puneetlath (AutoAssignerTriage), see https://stackoverflow.com/c/expensify/questions/4749 for more details.

[dklymenk]

Sadly, I do not have a proposal for this issue, since I believe it is caused by a response from BE.

Here are my findings that lead me to believe it's a BE issue.

The main reason the message is not updated is because sequenceNumber passed to updateReportActionMessage function is always equal to -1. This causes the function to create new reportAction with key -1 instead of updating text for deleted message. Please note that this is not the case for edited messages where sequenceNumber is correct. Issue occurs only when edited text message is empty (aka deleted message).

To make sure the -1 comes from BE, I checked the WS messages with dev tools. Here is an example message with an invalid sequenceNumber:

I hope it helps.

[puneetlath]

Nice find @dklymenk! I was able to reproduce this as well.

[MelvinBot]

Triggered auto assignment to @Dal-Papa (Engineering), see https://stackoverflow.com/c/expensify/questions/4319 for more details.

[MelvinBot]

Triggered auto assignment to @puneetlath (External), see https://stackoverflow.com/c/expensify/questions/8582 for more details.

[dklymenk]

Is BE repo available for upwork contractors? Why the External label?

[Dal-Papa]

@dklymenk : I think this could be decoupled between some backend features missing and then hooking it into the frontend. I will circle back once I have discussed with other engineers.

[puneetlath]

Removing the external label for now. @Dal-Papa feel free to re-add it when you're ready.

[Dal-Papa]

Sounds like we're gonna need to have some Pusher events fired off when deletion/edition happens so I'm going to create an internal GH first and keep that one open for when that's done and we can start listening to said event.

[dklymenk]

There is already a pusher event and it works for edition flawlessly. The issue is only with deletion and the fact that BE returns -1 instead of the actual sequenceNumber. Please my first comment #3524 (comment)

[dklymenk]

@Dal-Papa the way I see it, if BE starts returning proper sequenceNumber values, the issue on FE side will be automatically fixed.

[dklymenk]

I'm sorry, but was the issue on FE all along? Or were some changes required on BE too?

[Dal-Papa]

I'm sorry, but was the issue on FE all along? Or were some changes required on BE too?

No changes were made on the BE, it was simply the FE not sending the sequenceNumber to the BE when deleting a message.