[No-QA] fix: the web production build locally not working by TaduJR · Pull Request #71958 · Expensify/App

TaduJR · 2025-10-07T05:52:47Z

Explanation of Change

Problem: The production build script was misconfigured, causing developers to encounter CORS errors, 404 responses, and "You appear to be offline" messages when attempting to run production builds locally.

Root Cause:

The web:prod script only started a static file server without proxy support
API requests had nowhere to go except directly to production servers, triggering CORS violations
The .env.production file had USE_WEB_PROXY=false, preventing proper proxy configuration

Fixed Issues

$ #69854
PROPOSAL: #69854 (comment)

Tests

Prerequisites:

Ensure you have Node.js and all dependencies installed (npm install)
No services running on ports 8080 or 9000

Test 1: Production Build - Basic Functionality

Run npm run build to create the production bundle
Run npm run web:prod to start the production server
Verify both servers start successfully in the terminal:
- Proxy server: Proxy server listening at http://localhost:9000
- Web server: Available on: http://127.0.0.1:8080
Open browser to http://localhost:8080
Verify the app loads successfully (no blank screen)
Verify there is NO "You appear to be offline" message

Expected Result: App loads and shows as online

Verify that no errors appear in the JS console

Offline tests

QA Steps

// TODO: These must be filled out, or the issue title must include "[No QA]."

Verify that no errors appear in the JS console

PR Author Checklist

Screenshots/Videos

Android: Native

Android: mWeb Chrome

iOS: Native

iOS: mWeb Safari

MacOS: Chrome / Safari

MacOS: Desktop

github-actions · 2025-10-07T05:52:54Z

⚠️ This PR is possibly changing native code and/or updating libraries, it may cause problems with HybridApp. Please check if any patch updates are required in the HybridApp repo and run an AdHoc build to verify that HybridApp will not break. Ask Contributor Plus for help if you are not sure how to handle this. ⚠️

melvin-bot · 2025-10-08T21:24:18Z

@Pujan92 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]

codecov · 2025-10-08T21:33:13Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
see 23 files with indirect coverage changes

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Pujan92 · 2025-10-09T16:46:04Z

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: HybridApp
- Android: mWeb Chrome
- iOS: HybridApp
- 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: HybridApp

Android: mWeb Chrome

iOS: HybridApp

iOS: mWeb Safari

MacOS: Chrome / Safari

MacOS: Desktop

Pujan92 · 2025-10-09T17:00:53Z

@@ -4,7 +4,7 @@ EXPENSIFY_URL=https://www.expensify.com/
 EXPENSIFY_PARTNER_NAME=chat-expensify-com
 EXPENSIFY_PARTNER_PASSWORD=e21965746fd75f82bb66
 PUSHER_APP_KEY=268df511a204fbb60884
-USE_WEB_PROXY=false
+USE_WEB_PROXY=true


Suggested change

USE_WEB_PROXY=true

USE_WEB_PROXY=false

I don't think we need this change in the repo, otherwise on build prod it will set proxy thing which isn't needed.

Yep, let's remove this change and add info to readme

Pujan92 · 2025-10-09T17:01:45Z

@@ -29,7 +29,7 @@
    "web": "./scripts/set-pusher-suffix.sh && concurrently npm:web-proxy npm:web-server",
    "web-proxy": "ts-node web/proxy.ts",
    "web-server": "./scripts/start-dev-with-auto-restart.sh",
-    "build": "webpack --config config/webpack/webpack.common.ts --env file=.env.production && ts-node ./scripts/combine-web-sourcemaps.ts",
+    "build": "NODE_OPTIONS=--max_old_space_size=8192 webpack --config config/webpack/webpack.common.ts --env file=.env.production && ts-node ./scripts/combine-web-sourcemaps.ts",


Do we really need this change?

For me it worked without it

Pujan92 · 2025-10-09T17:05:53Z

@@ -75,7 +75,7 @@
    "react-compiler-compliance-check": "ts-node scripts/react-compiler-compliance-check.ts",
    "generate-search-parser": "peggy --format es -o src/libs/SearchParser/searchParser.js src/libs/SearchParser/searchParser.peggy src/libs/SearchParser/baseRules.peggy",
    "generate-autocomplete-parser": "peggy --format es -o src/libs/SearchParser/autocompleteParser.js src/libs/SearchParser/autocompleteParser.peggy src/libs/SearchParser/baseRules.peggy && ./scripts/parser-workletization.sh src/libs/SearchParser/autocompleteParser.js",
-    "web:prod": "http-server ./dist --cors",
+    "web:prod": "concurrently \"npm:web-proxy\" \"http-server ./dist --cors --port 8080 -P http://localhost:9000\"",


Suggested change

"web:prod": "concurrently \"npm:web-proxy\" \"http-server ./dist --cors --port 8080 -P http://localhost:9000\"",

"web:dist": "concurrently \"npm:web-proxy\" \"http-server ./dist --cors --port 8080 -P http://localhost:9000\"",

As this will be a common for staging/prod, how about any common name?

I agree with Pujan

Pujan92 · 2025-10-09T17:06:46Z

Also Tagging @blazejkustra and @LukasMod for review 👀

blazejkustra · 2025-10-10T06:11:34Z

@@ -4,7 +4,7 @@ EXPENSIFY_URL=https://www.expensify.com/
 EXPENSIFY_PARTNER_NAME=chat-expensify-com
 EXPENSIFY_PARTNER_PASSWORD=e21965746fd75f82bb66
 PUSHER_APP_KEY=268df511a204fbb60884
-USE_WEB_PROXY=false
+USE_WEB_PROXY=true


Yep, let's remove this change and add info to readme

blazejkustra · 2025-10-10T06:12:11Z

This feels a bit generated to me, sorry 😆

Btw I don't think we need this much information, the part in SETUP_WEB should be enough

This feels a bit generated to me, sorry 😆

Hehe No problem. I wrote the some and refactored with generation. I thought I might be helpful

blazejkustra · 2025-10-10T06:12:59Z

@@ -29,7 +29,7 @@
    "web": "./scripts/set-pusher-suffix.sh && concurrently npm:web-proxy npm:web-server",
    "web-proxy": "ts-node web/proxy.ts",
    "web-server": "./scripts/start-dev-with-auto-restart.sh",
-    "build": "webpack --config config/webpack/webpack.common.ts --env file=.env.production && ts-node ./scripts/combine-web-sourcemaps.ts",
+    "build": "NODE_OPTIONS=--max_old_space_size=8192 webpack --config config/webpack/webpack.common.ts --env file=.env.production && ts-node ./scripts/combine-web-sourcemaps.ts",


For me it worked without it

blazejkustra · 2025-10-10T06:13:13Z

@@ -75,7 +75,7 @@
    "react-compiler-compliance-check": "ts-node scripts/react-compiler-compliance-check.ts",
    "generate-search-parser": "peggy --format es -o src/libs/SearchParser/searchParser.js src/libs/SearchParser/searchParser.peggy src/libs/SearchParser/baseRules.peggy",
    "generate-autocomplete-parser": "peggy --format es -o src/libs/SearchParser/autocompleteParser.js src/libs/SearchParser/autocompleteParser.peggy src/libs/SearchParser/baseRules.peggy && ./scripts/parser-workletization.sh src/libs/SearchParser/autocompleteParser.js",
-    "web:prod": "http-server ./dist --cors",
+    "web:prod": "concurrently \"npm:web-proxy\" \"http-server ./dist --cors --port 8080 -P http://localhost:9000\"",


I agree with Pujan

blazejkustra · 2025-10-10T06:13:33Z

+npm run build
+
+# 2. Run the production server
+npm run web:prod


Here as well

Suggested change

npm run web:prod

npm run web:dist

LukasMod · 2025-10-10T07:39:23Z

+
+The `web:dist` command starts both the proxy server (port 9000) and web server (port 8080) concurrently. Access the application at **http://localhost:8080**
+
+**Important**: You must set `USE_WEB_PROXY=true` before running `web:dist` to avoid CORS errors when testing locally.


Are you sure it’s not supposed to be the first step? The solution works for me if I set the flag before running npm run build, since it uses that environment variable during the build process. When I did it in described order I got cors errors.

Yea thanks @LukasMod I think I was running cached build. Forgot during that. Fixed it.

NP. Good work!

blazejkustra · 2025-10-10T12:37:38Z

 * [React StrictMode](contributingGuides/STRICT_MODE.md)
 * [Left Hand Navigation(LHN)](contributingGuides/LEFT_HAND_NAVIGATION.md)
 * [HybridApp - additional info & troubleshooting](contributingGuides/HYBRID_APP.md)
+* [Running Production Builds Locally](contributingGuides/PRODUCTION_BUILD.md)


This can be removed as well 👍

Pujan92

LGTM, Thanks!

Screen.Recording.2025-10-10.at.18.58.42.mov

OSBotify · 2025-10-10T17:56:07Z

✋ 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 · 2025-10-13T21:21:00Z

🚀 Deployed to staging by https://github.com/thienlnam in version: 9.2.30-0 🚀

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

OSBotify · 2025-10-14T17:35:26Z

🚀 Deployed to production by https://github.com/mountiny in version: 9.2.30-6 🚀

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

melvin-bot Bot assigned TaduJR Oct 7, 2025

TaduJR mentioned this pull request Oct 7, 2025

[Due for payment 2025-10-21] Fix the web production build locally not working #69854

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TaduJR force-pushed the fix-the-web-production-build-locally-not-working branch from 686051a to dfaf1a5 Compare October 8, 2025 21:19

TaduJR marked this pull request as ready for review October 8, 2025 21:24

TaduJR requested a review from a team as a code owner October 8, 2025 21:24

melvin-bot Bot requested review from Pujan92 and removed request for a team October 8, 2025 21:24

TaduJR changed the title ~~fix: the web production build locally not working~~ [No-QA] fix: the web production build locally not working Oct 9, 2025

Pujan92 reviewed Oct 9, 2025

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blazejkustra suggested changes Oct 10, 2025

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[No-QA] fix: the web production build locally not working

74ba741

TaduJR force-pushed the fix-the-web-production-build-locally-not-working branch from faebb72 to 74ba741 Compare October 10, 2025 07:22

TaduJR requested review from Pujan92 and blazejkustra October 10, 2025 07:35

LukasMod reviewed Oct 10, 2025

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sync

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Update README.md

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melvin-bot Bot requested a review from thienlnam October 10, 2025 13:23

thienlnam approved these changes Oct 10, 2025

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thienlnam merged commit 646d96d into Expensify:main Oct 10, 2025
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TaduJR deleted the fix-the-web-production-build-locally-not-working branch October 13, 2025 14:53

OSBotify mentioned this pull request Oct 13, 2025

Deploy Checklist: New Expensify 2025-10-13 #72503

Closed

92 tasks

	"web:prod": "concurrently \"npm:web-proxy\" \"http-server ./dist --cors --port 8080 -P http://localhost:9000\"",
	"web:dist": "concurrently \"npm:web-proxy\" \"http-server ./dist --cors --port 8080 -P http://localhost:9000\"",


		The `web:dist` command starts both the proxy server (port 9000) and web server (port 8080) concurrently. Access the application at http://localhost:8080

		Important: You must set `USE_WEB_PROXY=true` before running `web:dist` to avoid CORS errors when testing locally.

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Explanation of Change

Fixed Issues

Tests

Offline tests

QA Steps

PR Author Checklist

Screenshots/Videos

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