[HOLD for payment 2023-10-02] Memoize expensive calls in ReportActionsList renderItem

[mountiny]

Problem

Some of the operations we do in ReportActionsList renderItem are pretty expensive since this function is executed for every items in the render window every time the render window changes. To improve performance of FlatList scrolling we need to move any expensive computation inside a memoized component. This way when FlatList re-renders to display new items but the data did not change only the new rendered items will need to render.

We were already memoizing ReportActionItem, but renderItem still contains some expensive calls, specifically isConsecutiveActionMadeByPreviousActor which has to do some date comparisons. I moved those to a new component ReportActionsListItemRenderer which will prevent any re-renders coming from from FlatList for items that were already rendered. This reduces the number of calls to isConsecutiveActionMadeByPreviousActor from the number of currently rendered item (~100 depending on the FlatList window size) to just the new items being added (usually 10 since this is the batch size).

[mountiny]

merged

[melvin-bot]

Triggered auto assignment to @sonialiap (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

[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 1.3.73-1 and is now subject to a 7-day regression period 📆. Here is the list of pull requests that resolve this issue:

• [NoQA] Memoize expensive calls in ReportActionsList renderItem #27957

If no regressions arise, payment will be issued on 2023-10-02. 🎊

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:

• @mollfpr requires payment

As a reminder, here are the bonuses/penalties that should be applied for any External issue:

• Merged PR within 3 business days of assignment - 50% bonus
• Merged PR more than 9 business days after assignment - 50% penalty

[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:

• [@mollfpr] The PR that introduced the bug has been identified. Link to the PR:
• [@mollfpr] 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:
• [@mollfpr] 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:
• [@mollfpr] Determine if we should create a regression test for this bug.
• [@mollfpr] 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.
• [@sonialiap] Link the GH issue for creating/updating the regression test once above steps have been agreed upon:

[mollfpr]

@mountiny @sonialiap I think there's nothing we can add to the BZ checklist.

[mountiny]

I agree, no need here for the checklist

[mollfpr]

@sonialiap I think I can request payment in NewDot for this issue.

[JmillsExpensify]

@sonialiap Can you please add a payment summary to this issue so I can pay?

[melvin-bot]

@sonialiap, @mollfpr, @mountiny Uh oh! This issue is overdue by 2 days. Don't forget to update your issues!

[sonialiap]

Sorry for the delay, working 50% while trying to juggle the normal work load.

Payment:

• @mollfpr review + time bonus = $750

[JmillsExpensify]

$750 payment approved for @mollfpr based on BZ summary.

[mollfpr]

@sonialiap @JmillsExpensify Sorry to open this up. I just noticed that the request on the ND I did was requested and approved for $500, so there's there is a shortage in payment here. Could you help confirm it? Thank you!

[mollfpr]

Friendly bump @JmillsExpensify