[HOLD for payment 2023-11-02] [$2000] IOU : Inconsistent behavior when long pressing the back button in Android app vs mWeb

[kavimuru]

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---

Action Performed:

1. Click FAB on Chrome mobile
2. Click Reqeust Money/ Split Bill
3. Enter amount more than 3 digits (e.g 6323)
4. Hold the back key "<"

Expected Result:

Last digit is removed and cursor is still at last place like Android app

Actual Result:

Last digit is removed but cursor is in front of last character

Workaround:

Can the user still use Expensify without this being fixed? Have you informed them of the workaround?

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: 1.3.43-2
Reproducible in staging?: y
Reproducible in production?: y
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

videoplayback.mp4

az_recorder_20230720_150324.1.mp4

Expensify/Expensify Issue URL:
Issue reported by: @ygshbht
Slack conversation: https://expensify.slack.com/archives/C049HHMV9SM/p1689740152146159

View all open jobs on GitHub

Upwork Automation - Do Not Edit

• Upwork Job URL: https://www.upwork.com/jobs/~0186b5465f1e6964a7
• Upwork Job ID: 1684547845836894208
• Last Price Increase: 2023-10-13
• Automatic offers:
• abdulrahuman5196 | Reviewer | 27293534

[melvin-bot]

Triggered auto assignment to @michaelhaxhiu (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

[kavimuru]

Proposal

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

Inconsistent cursor behavior when a user long-presses the back button on the 'Split Bill/Request Money' page between Android app and mobile web.

What is the root cause of that problem?

React's state management involves batching state updates for performance optimization, and in the current implementation, the setSelection function in setNewAmount (MoneyRequestAmountPage component) function seems to be getting called more than once. This leads to unpredictable cursor behavior due to the asynchronous nature of state updates in React.

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

The solution focuses on preventing multiple invocations of setSelection within setAmount. We introduce a flag hasSelectionBeenSet that allows setSelection to be called only once, thereby aligning cursor behavior across different platforms.
Original code block:

const setNewAmount = (newAmount) => {
    const newAmountWithoutSpaces = stripSpacesFromAmount(newAmount);
    if (!validateAmount(newAmountWithoutSpaces)) {
        setAmount((prevAmount) => prevAmount);
        setSelection((prevSelection) => ({...prevSelection}));
        return;
    }
    setAmount((prevAmount) => {
        setSelection((prevSelection) => getNewSelection(prevSelection, prevAmount.length, newAmountWithoutSpaces.length));
        return stripCommaFromAmount(newAmountWithoutSpaces);
    });
};

Modified code block:

const setNewAmount = (newAmount) => {
    const newAmountWithoutSpaces = stripSpacesFromAmount(newAmount);
    if (!validateAmount(newAmountWithoutSpaces)) {
        setAmount((prevAmount) => prevAmount);
        setSelection((prevSelection) => ({...prevSelection}));
        return;
    }
    let hasSelectionBeenSet = false;
    setAmount((prevAmount) => {
        if (!hasSelectionBeenSet) {
            setSelection((prevSelection) => {
                hasSelectionBeenSet = true;
                return getNewSelection(prevSelection, prevAmount.length, newAmountWithoutSpaces.length);
            });
        }
        return stripCommaFromAmount(newAmountWithoutSpaces);
    });
};

[ygshbht]

Thanks Kavi.

---

To add more details

App/src/pages/iou/steps/MoneyRequestAmountPage.js

Lines 291 to 306 in df6d03b

	const setNewAmount = (newAmount) => {
	// Remove spaces from the newAmount value because Safari on iOS adds spaces when pasting a copied value
	// More info: https://github.com/Expensify/App/issues/16974
	const newAmountWithoutSpaces = stripSpacesFromAmount(newAmount);
	// Use a shallow copy of selection to trigger setSelection
	// More info: https://github.com/Expensify/App/issues/16385
	if (!validateAmount(newAmountWithoutSpaces)) {
	setAmount((prevAmount) => prevAmount);
	setSelection((prevSelection) => ({...prevSelection}));
	return;
	}
	setAmount((prevAmount) => {
	setSelection((prevSelection) => getNewSelection(prevSelection, prevAmount.length, newAmountWithoutSpaces.length));
	return stripCommaFromAmount(newAmountWithoutSpaces);
	});
	};

What alternative solutions did you explore? (Optional)

A bit more complex solution involves moving setSelection out of setAmount and doing some restructuring to acheive the same result

Working solution:

XRecorder_19072023_083315.mp4

---

Regarding the alternate solution:

You could also club amount and selection in one state variable as they are almost always updated together
So the new modification instead of this

let hasSelectionBeenSet = false;
setAmount((prevAmount) => {
    if (!hasSelectionBeenSet) {
        setSelection((prevSelection) => {
            hasSelectionBeenSet = true;
            return getNewSelection(prevSelection, prevAmount.length, newAmountWithoutSpaces.length);
        });
    }
    return stripCommaFromAmount(newAmountWithoutSpaces);
});

can be:

setAmountAndSelection(({amount, selection})=>{
    return { amount:stripCommaFromAmount(newAmountWithoutSpaces),
        selection: getNewSelection(selection, amount.length, newAmountWithoutSpaces.length)
    }
})

[melvin-bot]

@michaelhaxhiu Eep! 4 days overdue now. Issues have feelings too...

[melvin-bot]

Job added to Upwork: https://www.upwork.com/jobs/~0186b5465f1e6964a7

[melvin-bot]

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

[melvin-bot]

Triggered auto assignment to Contributor-plus team member for initial proposal review - @abdulrahuman5196 (External)

[michaelhaxhiu]

Passing to External

[abdulrahuman5196]

Reviewing today

[michaelhaxhiu]

How's review coming @abdulrahuman5196 🐰 ?

[melvin-bot]

📣 It's been a week! Do we have any satisfactory proposals yet? Do we need to adjust the bounty for this issue? 💸

[abdulrahuman5196]

Will check in my morning. Was working on WAQ crossed issues and deploy blockers.

[melvin-bot]

@michaelhaxhiu @abdulrahuman5196 this issue was created 2 weeks ago. Are we close to approving a proposal? If not, what's blocking us from getting this issue assigned? Don't hesitate to create a thread in #expensify-open-source to align faster in real time. Thanks!

[melvin-bot]

Upwork job price has been updated to $2000

[ygshbht]

@abdulrahuman5196 The PR is ready for review

[melvin-bot]

Based on my calculations, the pull request did not get merged within 3 working days of assignment. Please, check out my computations here:

• when @ygshbht got assigned: 2023-10-20 11:53:51 Z
• when the PR got merged: 2023-10-25 14:14:42 UTC
• days elapsed: 3

On to the next one 🚀

[ygshbht]

@laurenreidexpensify @madmax330 Will the job be eligible for bonus? PR was created within hours of assignment and C+ approved the changes within 2 days. The wait was for @madmax330 to approve. Thanks!

[abdulrahuman5196]

Will the job be eligible for bonus? PR was created within hours of assignment and C+ approved the changes within 2 days.

This would be yes similar to other issues IMO.

[melvin-bot]

Reviewing label has been removed, please complete the "BugZero Checklist".

[melvin-bot]

The solution for this issue has been 🚀 deployed to production 🚀 in version 1.3.91-8 and is now subject to a 7-day regression period 📆. Here is the list of pull requests that resolve this issue:

• Resolve Cursor Position Issue on Long-Press in Android Chrome #30082

If no regressions arise, payment will be issued on 2023-11-02. 🎊

After the hold period is over and BZ checklist items are completed, please complete any of the applicable payments for this issue, and check them off once done.

• External issue reporter
• Contributor that fixed the issue
• Contributor+ that helped on the issue and/or PR

For reference, here are some details about the assignees on this issue:

• @abdulrahuman5196 requires payment offer (Reviewer)
• @ygshbht requires payment
• @ygshbht requires payment

[melvin-bot]

BugZero Checklist: The PR fixing this issue has been merged! The following checklist (instructions) will need to be completed before the issue can be closed:

• [@abdulrahuman5196] The PR that introduced the bug has been identified. Link to the PR:
• [@abdulrahuman5196] The offending PR has been commented on, pointing out the bug it caused and why, so the author and reviewers can learn from the mistake. Link to comment:
• [@abdulrahuman5196] A discussion in #expensify-bugs has been started about whether any other steps should be taken (e.g. updating the PR review checklist) in order to catch this type of bug sooner. Link to discussion:
• [@abdulrahuman5196] Determine if we should create a regression test for this bug.
• [@abdulrahuman5196] If we decide to create a regression test for the bug, please propose the regression test steps to ensure the same bug will not reach production again.
• [@laurenreidexpensify] Link the GH issue for creating/updating the regression test once above steps have been agreed upon:

[abdulrahuman5196]

The PR that introduced the bug has been identified. Link to the PR:
The offending PR has been commented on, pointing out the bug it caused and why, so the author and reviewers can learn from the mistake. Link to comment:
A discussion in #expensify-bugs has been started about whether any other steps should be taken (e.g. updating the PR review checklist) in order to catch this type of bug sooner. Link to discussion:

Not a regression. Seems to be the behaviour for long time.

Determine if we should create a regression test for this bug.

Yes.

If we decide to create a regression test for the bug, please propose the regression test steps to ensure the same bug will not reach production again.

1. Click FAB on Chrome mobile
2. Click Reqeust Money/ Split Bill
3. Enter amount more than 3 digits (e.g 6323)
4. Hold the back key "<"
5. Verify that last digit is removed and cursor is still at last place

[laurenreidexpensify]

Payment Summary:

• External issue reporter @ygshbht $250 - please apply to job in Upwork
• Contributor that fixed the issue @ygshbht $2000 + $1000 bonus - please apply to job in Upwork
• Contributor+ that helped on the issue and/or PR @abdulrahuman5196 - $2000 + $1000 bonus - payment issued in Upwork

[laurenreidexpensify]

@ygshbht please accept job in Upwork - https://www.upwork.com/en-gb/jobs/~0175ccda3750737e98

[ygshbht]

Thanks. Accepted!