[NoQA] feat: react-compiler

[kirillzyusko]

Details

Added react-compiler that automatically applies necessary memo/useMemo/etc. and improves performance of the app.

To add this compiler I had:

• to patch eslint plugin (the PR was merged [React Compiler] use filename instead of context.filename in ESLint plugin facebook/react#29104 -> will be available in next release);
• to add react-compiler-runtime package manually (the react-compiler-runtime is available by default in react@19, but react@19 is not compatible with RN 0.73/0.74, so we had to wait before the upgrade - more reasonable was to add missing runtime and link it manually for now);

Below two screenshots from react-devtools showing that compiler actually works:

Before	After

Warning

As of react-native@0.73 the new badge with memo will not be shown (though optimization will be applied. Read an explanation here.

After running performance e2e tests I got next results (comparing to current main):

❇️ Performance comparison results:
➡️ Significant changes to duration

Open Chat Finder Page TTI: 2758.066 ms → 2639.980 ms (-118.086 ms, -4.3%)
➡️ Meaningless changes to duration

App start nativeLaunch: 91.750 ms → 93.517 ms (+1.767 ms, +1.9%)
App start nativeLaunchEnd_To_appCreationStart: 91.737 ms → 90.877 ms (-0.860 ms, -0.9%)
App start appCreation: 108.133 ms → 111.817 ms (+3.683 ms, +3.4%)
App start appCreationEnd_To_contentAppeared: 1116.733 ms → 1108.483 ms (-8.250 ms, -0.7%)
App start contentAppeared_To_screenTTI: 2324.047 ms → 2343.516 ms (+19.469 ms, +0.8%)
App start runJsBundle: 863.983 ms → 849.467 ms (-14.517 ms, -1.7%)
App start TTI: 3745.847 ms → 3750.249 ms (+4.403 ms, ±0.0%)
App start regularAppStart: 0.060 ms → 0.061 ms (+0.000 ms, ±0.0%)
Load Search Options: 403.670 ms → 415.041 ms (+11.370 ms, +2.8%)
Chat opening: 84.929 ms → 87.507 ms (+2.578 ms, +3.0%)
Chat TTI: 1522.559 ms → 1513.895 ms (-8.664 ms, -0.6%)

Fixed Issues

$ #42211
PROPOSAL: N/A

Tests

• Verify that no errors appear in the JS console

Offline tests

N/A

QA Steps

• Verify that no errors appear in the JS console

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)
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  • 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 either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
  • I verified proper file naming conventions were followed for any new files or renamed files. All non-platform specific files are named after what they export and are not named "index.js". All platform-specific files are named for the platform the code supports as outlined in the README.
  • 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.
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
• If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
  • I verified that all the inputs inside a form are aligned with each other.
  • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
• If a new page is added, I verified it's using the ScrollView component to make it scrollable when more elements are added to the page.
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.

Screenshots/Videos

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

MacOS: Desktop

[melvin-bot]

@Ollyws Please copy/paste the Reviewer Checklist from here into a new comment on this PR and complete it. If you have the K2 extension, you can simply click: [this button]

[Ollyws]

Perf test are failing on this one.

[kirillzyusko]

@Ollyws I fixed jest tests 👍 Validate GH actions is still failing, but I strongly believe it's not related to my changes (I've tried to execute this action/step on a main branch and I'm getting the same output).

[Ollyws]

Reviewer Checklist

• I have verified the author checklist is complete (all boxes are checked off).
• I verified the correct issue is linked in the ### Fixed Issues section above
• I verified testing steps are clear and they cover the changes made in this PR
  • I verified the steps for local testing are in the Tests section
  • I verified the steps for Staging and/or Production testing are in the QA steps section
  • I verified the steps cover any possible 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 checked that screenshots or videos are included for tests on all platforms
• I included screenshots or videos for tests on all platforms
• I verified tests pass on all platforms & I tested again on:
  • Android: Native
  • Android: mWeb Chrome
  • iOS: Native
  • iOS: mWeb Safari
  • MacOS: Chrome / Safari
  • MacOS: Desktop
• If there are any errors in the console that are unrelated to this PR, I either fixed them (preferred) or linked to where I reported them in Slack
• I verified proper code patterns were followed (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
  • 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 either coming verbatim from figma or has been approved by marketing (in order to get marketing approval, ask the Bug Zero team member to add the Waiting for copy label to the issue)
  • I verified proper file naming conventions were followed for any new files or renamed files. All non-platform specific files are named after what they export and are not named "index.js". All platform-specific files are named for the platform the code supports as outlined in the README.
  • 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 verified that this PR follows the guidelines as stated in the Review Guidelines
• I verified other components that can be impacted by these changes have been tested, and I retested again (i.e. if the PR modifies a shared library or component like Avatar, I verified the components using Avatar have been tested & I retested again)
• 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
• If a new component is created I verified that:
  • A similar component doesn't exist in the codebase
  • All props are defined accurately and each prop has a /** comment above it */
  • The file is named correctly
  • The component has a clear name that is non-ambiguous and the purpose of the component can be inferred from the name alone
  • The only data being stored in the state is data necessary for rendering and nothing else
  • For Class Components, any internal methods passed to components event handlers are bound to this properly so there are no scoping issues (i.e. for onClick={this.submit} the method this.submit should be bound to this in the constructor)
  • Any internal methods bound to this are necessary to be bound (i.e. avoid this.submit = this.submit.bind(this); if this.submit is never passed to a component event handler like onClick)
  • All JSX used for rendering exists in the render method
  • The component has the minimum amount of code necessary for its purpose, and it is broken down into smaller components in order to separate concerns and functions
• 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.
• If the PR modifies a generic component, I tested and verified that those changes do not break usages of that component in the rest of the App (i.e. if a shared library or component like Avatar is modified, I verified that Avatar is working as expected in all cases)
• If the PR modifies a component related to any of the existing Storybook stories, I tested and verified all stories for that component are still working as expected.
• If the PR modifies a component or page that can be accessed by a direct deeplink, I verified that the code functions as expected when the deeplink is used - from a logged in and logged out account.
• If the PR modifies the UI (e.g. new buttons, new UI components, changing the padding/spacing/sizing, moving components, etc) or modifies the form input styles:
  • I verified that all the inputs inside a form are aligned with each other.
  • I added Design label and/or tagged @Expensify/design so the design team can review the changes.
• If a new page is added, I verified it's using the ScrollView component to make it scrollable when more elements are added to the page.
• If the main branch was merged into this PR after a review, I tested again and verified the outcome was still expected according to the Test steps.
• I have checked off every checkbox in the PR reviewer checklist, including those that don't apply to this PR.

Screenshots/Videos

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

MacOS: Desktop

[Ollyws]

LGTM.

[melvin-bot]

We did not find an internal engineer to review this PR, trying to assign a random engineer to #42211 as well as to this PR... Please reach out for help on Slack if no one gets assigned!

[kirillzyusko]

@mountiny what are the next steps here? I remember you wanted to discuss it on Monday so it's a friendly reminder 👀

My understanding is that it's pretty stable and we have a control of each file (so we always can disable unnecessary optimizations if needed).

[mountiny]

thank you @kirillzyusko this seems like it works and tests well

I am curious if @roryabraham @AndrewGable have any concerns with adding this now

[AndrewGable]

Should we run an AdHoc regression test to see any thing breaks? It seems like it might be a decent idea

[mountiny]

running

[AndrewGable]

There are no changes for the failing test on main, can you see if the npm run gh-actions-build command does produce a diff on this branch? I think we should commit those changes if so.

[roryabraham]

Also, does this mean that we should start changing the way we write code such that we don't use useMemo, useCallback, etc... and just let the React Compiler handle memoization on its own?

[roryabraham]

I feel like the real test here would be to take some optimized but complex/less-readable code in an important component, remove all memoization, and then see how well the React Compiler does to automatically add memoization.

[mountiny]

Asked for QA testing https://expensify.slack.com/archives/C9YU7BX5M/p1717521040631869

[kirillzyusko]

There are no changes for the failing test on main, can you see if the npm run gh-actions-build command does produce a diff on this branch? I think we should commit those changes if so.

@AndrewGable I pulled lates main again, and it produced a different output again. I committed modified file, but may I ask you to shed some light on why it happens? I simply added new dependency to package.json - why it affected a compilation of GH action file? 🤔

[kirillzyusko]

Also, does this mean that we should start changing the way we write code such that we don't use useMemo, useCallback, etc... and just let the React Compiler handle memoization on its own?

@roryabraham I think yes, but I would keep writing it - just to see how compiler behaves, and if it really works, then we can gradually abandon manual memoization 🙃

I feel like the real test here would be to take some optimized but complex/less-readable code in an important component, remove all memoization, and then see how well the React Compiler does to automatically add memoization.

Yeah, can be a very good use case to verify 👍

[kirillzyusko]

Should we run an AdHoc regression test to see any thing breaks? It seems like it might be a decent idea

@mountiny may I kindly ask you to re-trigger a new build? I think for a previous build I haven't updated a branch for a pretty long time, so I assume it may have old bugs. Now I rebased all my changes, so it should be in more up-to-date state (but if you think that we can test previous build, then I'm not against it).

[mountiny]

Thanks

[OSBotify]

✋ This PR was not deployed to staging yet because QA is ongoing. It will be automatically deployed to staging after the next production release.

[OSBotify]

🚀 Deployed to staging by https://github.com/mountiny in version: 9.0.2-0 🚀

platform	result
🤖 android 🤖	success ✅
🖥 desktop 🖥	success ✅
🍎 iOS 🍎	success ✅
🕸 web 🕸	success ✅

[OSBotify]

🚀 Deployed to production by https://github.com/jasperhuangg in version: 9.0.3-7 🚀

platform	result
🤖 android 🤖	success ✅
🖥 desktop 🖥	success ✅
🍎 iOS 🍎	success ✅
🕸 web 🕸	success ✅

[rushatgabhane]

Note: this PR caused a bug - #42287

[mountiny]

@rushatgabhane I think you have linked back to this PR

[OSBotify]

🚀 Deployed to production by https://github.com/Julesssss in version: 9.0.5-13 🚀

platform	result
🤖 android 🤖	success ✅
🖥 desktop 🖥	success ✅
🍎 iOS 🍎	success ✅
🕸 web 🕸	success ✅

[shubham1206agra]

This PR caused a bug where the report name is getting cached. More info #44295