[HOLD for payment 2023-09-29] [$500] Report - Conversation history does not scroll down after sending a message and IOU

[lanitochka17]

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Action Performed:

Preconditions:
Log in using a HIGH traffic account.

1. Open New Expensify app
2. Navigate to a chat that has a very long history
3. Scroll up the conversation history
4. Send any message or IOU

Expected Result:

When you send a message or IOU in a conversation, the message history should scroll down without artifacts to the newly sent message or IOU

Actual Result:

When sending a message or IOU in a conversation, the message history doesn't scroll down, and on Native apps the conversation history starts scrolling chaotically up to down

Workaround:

Unknown

Platforms:

Which of our officially supported platforms is this issue occurring on?

• Android / native
• Android / Chrome
• iOS / native
• iOS / Safari
• MacOS / Chrome / Safari
• MacOS / Desktop

Version Number: 1.3.60-1

Reproducible in staging?: Yes

Reproducible in production?: Yes

If this was caught during regression testing, add the test name, ID and link from TestRail:

Email or phone of affected tester (no customers):

Logs: https://stackoverflow.com/c/expensify/questions/4856

Notes/Photos/Videos: Any additional supporting documentation

Bug6184276_Recording_KI_22367_Android.mp4

Expensify/Expensify Issue URL:

Issue reported by: @rayane-djouah

Slack conversation: https://expensify.slack.com/archives/C049HHMV9SM/p1692633002201879

View all open jobs on GitHub

Upwork Automation - Do Not Edit

• Upwork Job URL: https://www.upwork.com/jobs/~016b9e851c8568700f
• Upwork Job ID: 1697745435700506624
• Last Price Increase: 2023-09-08
• Automatic offers:
• mollfpr | Reviewer | 26624598
• rayane-djouah | Contributor | 26624600
• rayane-djouah | Reporter | 26624601

[melvin-bot]

Triggered auto assignment to @sakluger (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details.

[melvin-bot]

Bug0 Triage Checklist (Main S/O)

• This "bug" occurs on a supported platform (ensure Platforms in OP are ✅)
• This bug is not a duplicate report (check E/App issues and #expensify-bugs)
  • If it is, comment with a link to the original report, close the issue and add any novel details to the original issue instead
• This bug is reproducible using the reproduction steps in the OP. S/O
  • If the reproduction steps are clear and you're unable to reproduce the bug, check with the reporter and QA first, then close the issue.
  • If the reproduction steps aren't clear and you determine the correct steps, please update the OP.
• This issue is filled out as thoroughly and clearly as possible
  • Pay special attention to the title, results, platforms where the bug occurs, and if the bug happens on staging/production.
• I have reviewed and subscribed to the linked Slack conversation to ensure Slack/Github stay in sync

[rayane-d]

@lanitochka17, I reported the same bug 10 days ago. You can find the details here: https://expensify.slack.com/archives/C049HHMV9SM/p1692633002201879. could you credit my name when addressing this? Thank you

[rayane-d]

Proposal

Please re-state the problem that we are trying to solve in this issue.

When a new message is sent by the current user, the app does not automatically scroll to the bottom.

What is the root cause of that problem?

The bug was introduced by this PR #18637. In this PR, this scrolling logic was removed from the ReportActionsView component while migrating the Unread Marker logic from ReportActionsView to ReportActionsList component.

The behavior before this PR was:

in the previous commit (before that PR), If a new message is sent and it's from the current user the app scroll to the bottom:

App/src/pages/home/report/ReportActionsView.js

Lines 155 to 161 in 8cd29e6

	const unsubscribe = Report.subscribeToNewActionEvent(reportID, (isFromCurrentUser, newActionID) => {
	const isNewMarkerReportActionIDSet = !_.isEmpty(newMarkerReportActionIDRef.current);
	// If a new comment is added and it's from the current user scroll to the bottom otherwise leave the user positioned where
	// they are now in the list.
	if (isFromCurrentUser) {
	scrollToBottom();

What changes do you think we should make in order to solve the problem?

Integrate the subscribeToNewActionEvent call within the ReportActionsList component, coinciding with the migrated unread marker logic:

// In the component we are subscribing to the arrival of new actions.
// As there is the possibility that there are multiple instances of a ReportScreen
// for the same report, we only ever want one subscription to be active, as
// the subscriptions could otherwise be conflicting.
const newActionUnsubscribeMap = {};

useEffect(() => {

    // Why are we doing this, when in the cleanup of the useEffect we are already calling the unsubscribe function?
    // Answer: On web, when navigating to another report screen, the previous report screen doesn't get unmounted,
    //         meaning that the cleanup might not get called. When we then open a report we had open already previosuly, a new
    //         ReportScreen will get created. Thus, we have to cancel the earlier subscription of the previous screen,
    //         because the two subscriptions could conflict!
    //         In case we return to the previous screen (e.g. by web back navigation) the useEffect for that screen would
    //         fire again, as the focus has changed and will set up the subscription correctly again.
    const previousSubUnsubscribe = newActionUnsubscribeMap[report.reportID];
    if (previousSubUnsubscribe) {
        previousSubUnsubscribe();
    }

    // This callback is triggered when a new action arrives via Pusher and the event is emitted from Report.js. This allows us to maintain
    // a single source of truth for the "new action" event instead of trying to derive that a new action has appeared from looking at props.
    const unsubscribe = Report.subscribeToNewActionEvent(report.reportID, (isFromCurrentUser) => {
        // If a new comment is added and it's from the current user scroll to the bottom otherwise leave the user positioned where
        // they are now in the list.
        if (!isFromCurrentUser)
            return;
        reportScrollManager.scrollToBottom();
    });
    const cleanup = () => {
        if (unsubscribe) {
            unsubscribe();
        }
        Report.unsubscribeFromReportChannel(report.reportID);
    };

    newActionUnsubscribeMap[report.reportID] = cleanup;

    return () => {
        cleanup();
    };
}, [report.reportID, reportScrollManager]);

Result:

31.New.Expensify.Mozilla.Firefox.2023-09-01.01-39-29.mp4

What alternative solutions did you explore? (Optional)

Alternative 1:

Reintegrate the subscribeToNewActionEvent call within the ReportActionsView component:

import useReportScrollManager from '../../../hooks/useReportScrollManager';

const reportScrollManager = useReportScrollManager();

// In the component we are subscribing to the arrival of new actions.
// As there is the possibility that there are multiple instances of a ReportScreen
// for the same report, we only ever want one subscription to be active, as
// the subscriptions could otherwise be conflicting.
const newActionUnsubscribeMap = {};

useEffect(() => {

    // Why are we doing this, when in the cleanup of the useEffect we are already calling the unsubscribe function?
    // Answer: On web, when navigating to another report screen, the previous report screen doesn't get unmounted,
    //         meaning that the cleanup might not get called. When we then open a report we had open already previosuly, a new
    //         ReportScreen will get created. Thus, we have to cancel the earlier subscription of the previous screen,
    //         because the two subscriptions could conflict!
    //         In case we return to the previous screen (e.g. by web back navigation) the useEffect for that screen would
    //         fire again, as the focus has changed and will set up the subscription correctly again.
    const previousSubUnsubscribe = newActionUnsubscribeMap[reportID];
    if (previousSubUnsubscribe) {
        previousSubUnsubscribe();
    }

    // This callback is triggered when a new action arrives via Pusher and the event is emitted from Report.js. This allows us to maintain
    // a single source of truth for the "new action" event instead of trying to derive that a new action has appeared from looking at props.
    const unsubscribe = Report.subscribeToNewActionEvent(reportID, (isFromCurrentUser) => {
        // If a new comment is added and it's from the current user scroll to the bottom otherwise leave the user positioned where
        // they are now in the list.
        if (!isFromCurrentUser)
            return;
        reportScrollManager.scrollToBottom();
    });
    const cleanup = () => {
        if (unsubscribe) {
            unsubscribe();
        }
        Report.unsubscribeFromReportChannel(reportID);
    };

    newActionUnsubscribeMap[reportID] = cleanup;

    return () => {
        cleanup();
    };
}, [reportID, reportScrollManager]);

Alternative 2:

We could potentially examine the sortedReportActions prop of ReportActionsList inferring the arrival of a new action solely based on prop changes as an alternative to the listener.

[melvin-bot]

Job added to Upwork: https://www.upwork.com/jobs/~016b9e851c8568700f

[melvin-bot]

Current assignee @sakluger is eligible for the External assigner, not assigning anyone new.

[melvin-bot]

Triggered auto assignment to Contributor-plus team member for initial proposal review - @mollfpr (External)

[rayane-d]

@mollfpr, could you please review my proposal when you get a chance? Thank you!