General purpose memoization tool

[kacper-mikolajczak]

Details

PR implements POC2 (continuation of #43538) of memoization tool for general purpose use. The main goal is to:

• implement array cache
• add unit tests
• add example in the wild
• implement monitoring for caches
• enable to collect stats globally
• discuss what should be added to the guidelines

Minor to do:

• Fix typings
• Fix eslint
• Discuss whether we should add functionality of copying static methods

Fixed Issues

$ #42200
PROPOSAL: https://expensify.slack.com/archives/C01GTK53T8Q/p1716371827915779

Tests

• Verify that no errors appear in the JS console

1. Scroll through LHN
2. Open report
3. Type an emoji (send message optionally)
4. Go back
5. Press FAB
6. Choose Submit Expense
7. Pick different currency
8. Go back
9. Navigate to Profile screen

Offline tests

N/A

QA Steps

• Verify that no errors appear in the JS console

1. Scroll through LHN
2. Open report
3. Type an emoji (send message optionally)
4. Go back
5. Press FAB
6. Choose Submit Expense
7. Pick different currency
8. Go back
9. Navigate to Profile screen

PR Author Checklist

• I linked the correct issue in the ### Fixed Issues section above
• I wrote clear testing steps that cover the changes made in this PR
  • I added steps for local testing in the Tests section
  • I added steps for the expected offline behavior in the Offline steps section
  • I added steps for Staging and/or Production testing in the QA steps section
  • I added steps to cover failure scenarios (i.e. verify an input displays the correct error message if the entered data is not correct)
  • I turned off my network connection and tested it while offline to ensure it matches the expected behavior (i.e. verify the default avatar icon is displayed if app is offline)
  • I tested this PR with a High Traffic account against the staging or production API to ensure there are no regressions (e.g. long loading states that impact usability).
• I included screenshots or videos for tests on all platforms
• I ran the tests on all platforms & verified they passed on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
  • MacOS: Desktop
• I verified there are no console errors (if there's a console error not related to the PR, report it or open an issue for it to be fixed)
• I followed proper code patterns (see Reviewing the code)
  • I verified that any callback methods that were added or modified are named for what the method does and never what callback they handle (i.e. toggleReport and not onIconClick)
  • I verified that the left part of a conditional rendering a React component is a boolean and NOT a string, e.g. myBool && <MyComponent />.
  • I verified that comments were added to code that is not self explanatory
  • I verified that any new or modified comments were clear, correct English, and explained "why" the code was doing something instead of only explaining "what" the code was doing.
  • I verified any copy / text shown in the product is localized by adding it to src/languages/* files and using the translation method
    • If any non-english text was added/modified, I verified the translation was requested/reviewed in #expensify-open-source and it was approved by an internal Expensify engineer. Link to Slack message:
  • I verified all numbers, amounts, dates and phone numbers shown in the product are using the localization methods
  • I verified any copy / text that was added to the app is grammatically correct in English. It adheres to proper capitalization guidelines (note: only the first word of header/labels should be capitalized), and is approved by marketing by adding the Waiting for Copy label for a copy review on the original GH to get the correct copy.
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  • I verified the JSDocs style guidelines (in STYLE.md) were followed
• If a new code pattern is added I verified it was agreed to be used by multiple Expensify engineers
• I followed the guidelines as stated in the Review Guidelines
• I tested other components that can be impacted by my changes (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar are working as expected)
• I verified all code is DRY (the PR doesn't include any logic written more than once, with the exception of tests)
• I verified any variables that can be defined as constants (ie. in CONST.js or at the top of the file that uses the constant) are defined as such
• I verified that if a function's arguments changed that all usages have also been updated correctly
• If any new file was added I verified that:
  • The file has a description of what it does and/or why is needed at the top of the file if the code is not self explanatory
• If a new CSS style is added I verified that:
  • A similar style doesn't already exist
  • The style can't be created with an existing StyleUtils function (i.e. StyleUtils.getBackgroundAndBorderStyle(theme.componentBG))
• If the PR modifies code that runs when editing or sending messages, I tested and verified there is no unexpected behavior for all supported markdown - URLs, single line code, code blocks, quotes, headings, bold, strikethrough, and italic.
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Screenshots/Videos

Android: Native

android.mp4

Android: mWeb Chrome

android-web.mp4

iOS: Native

ios.mov

iOS: mWeb Safari

ios-web.mp4

MacOS: Chrome / Safari

web.mp4

MacOS: Desktop

desktop.mp4

[kacper-mikolajczak]

Current state of the types in the memoize.index.ts is quite difficult to resolve without disabling no-unsafe-return rule.

Here is a TS Playground with minimal reproducible sample for the issue. Also here is a link to SO where the difficulty is discussed, but it is not 100% equivalent.

In general, the memoize method is quite self contained and straightforward so it should not be an issue to disable the rule but let's discuss what would be our next step.

If you know how to resolve the typings issue, please let me know 🙏

[mananjadhav]

Video of the issue:

mobile-web-issue.mov

[mananjadhav]

I completed the checklist pending mobile web screencasts, issues with my setup.

[mountiny]

@mananjadhav We have just changed the live-markdown package version in main so maybe you need to do clean npm install.

Creating an adhoc build though

[github-actions]

🧪🧪 Use the links below to test this adhoc build on Android, iOS, Desktop, and Web. Happy testing! 🧪🧪

Android 🤖	iOS 🍎
https://ad-hoc-expensify-cash.s3.amazonaws.com/android/43868/index.html	https://ad-hoc-expensify-cash.s3.amazonaws.com/ios/43868/index.html
Desktop 💻	Web 🕸️
https://ad-hoc-expensify-cash.s3.amazonaws.com/desktop/43868/NewExpensify.dmg	https://43868.pr-testing.expensify.com

---

👀 View the workflow run that generated this build 👀

[mananjadhav]

I tried reinstall with npm i, it didn't work. Anyway thanks for the adhoc build, will test now.

[mananjadhav]

@mountiny Tested and uploaded videos for the pending platforms (mobile web Chrome and mobile web Safari).

[kacper-mikolajczak]

Hi folks, thanks for the review guys! Recent changes consist:

• NumberFormatUtils broken into ios and general variant
• added explanation to intlPolyfill call in ios variant

When it comes to mobile web issues with sending a message, I've checked ad hoc builds and it worked fine. @mountiny @mananjadhav does the issue still exist?

message-not-sending-mweb.mov

Let me know if we are good to go, thanks! 👍

PS

There is a Verify Podfile check failing. We were not modyfing any dependencies in the last commit so I am not sure why it started to fail. @mananjadhav are you by any chance familiar with the issue? :D

[mananjadhav]

@kacper-mikolajczak Suggested a structure here

When it comes to mobile web issues with sending a message, I've checked ad hoc builds and it worked fine. @mountiny @mananjadhav does the issue still exist?

I tested on adhoc and it worked fine. Not sure something wrong with my local setup maybe.

[mananjadhav]

@kacper-mikolajczak The error seems to be on patch-package, @mountiny could you retry the job?

[mountiny]

We are seeing that fail on other PRs too, Fabio is looking right now

[kacper-mikolajczak]

Hi @mountiny! How is Verify Podfile investigation going?

[mountiny]

@kacper-mikolajczak this is fixed in main so you can merge main and it should be resolved

[mountiny]

@kacper-mikolajczak the lint seems to be failing now

[kacper-mikolajczak]

@mountiny Yup, there's a new use case (added just 2 days ago) about keyTransformer. Let's cover that before moving further! 🫡 🔧

[mananjadhav]

Will review once the change has been pushed.

[kacper-mikolajczak]

Current to do list:

• Refactor ArrayCache
• Implement keyTransformer (highest priority - In progress)
• Refactor Stats module (e.g. extract StatsEntry)
• Move Memoize global into MemoizeMonitor(Observer) module
• Extract equality comparator

Items below keyTransformer can be targeted after PR is merged. The keyTransformer is a critical feature request for now and in order to make it work, I need to work the way through typings. The main reason why is it non-trivial is that we have a mixture of maxArgs and keyTransformer which both modify cache's keys and the end user needs to be notified about it on the type level.

The maxArgs truncates the key (arguments list) and keyTransformer can yield arbitrary values (as it is in the recent use-case where arguments list is reduced to single string).

[Fun TS fact] Here is a code for truncating the tuples:

// Based on: https://stackoverflow.com/questions/67605122/obtain-a-slice-of-a-typescript-parameters-tuple
type TupleSplit<T, N extends number, O extends readonly any[] = readonly []> = O['length'] extends N
    ? [O, T]
    : T extends readonly [infer F, ...infer R]
    ? TupleSplit<readonly [...R], N, readonly [...O, F]>
    : [O, T];

type TakeFirst<T extends readonly any[], N extends number = T['length']> = TupleSplit<T, N>[0];

Now I need to connect it into generic options with keyTransformer so we are returning correct type. Please stay tuned 🙏

[kacper-mikolajczak]

Update: Needed to focus on other task for today, so no progress. I will be OOO Wednesday and Thursday, so let's get back to it on Friday!