[NO QA] Fix flaky MiddlewareTest by using resetQueue() in beforeEach by MelvinBot · Pull Request #87945 · Expensify/App

MelvinBot · 2026-04-15T03:08:54Z

Explanation of Change

The beforeEach in MiddlewareTest.ts called SequentialQueue.pause() which only sets isQueuePaused but does not reset isSequentialQueueRunning, currentRequestPromise, or isReadyPromise. This allowed in-flight requests from a previous test to leak into the next test, causing intermittent fetch call count mismatches (expected 1, received 3).

Replaced SequentialQueue.pause() with SequentialQueue.resetQueue() which fully resets all internal queue state between tests. resetQueue() already exists specifically for this purpose.

Fixed Issues

$ #87930

AI Tests

Ran MiddlewareTest.ts twice consecutively — all 7 tests passed both times, including the previously flaky test "OpenReport to a new chat without preexistingReportID and clean up optimistic participant data"
Ran npx prettier --write — no changes needed
Ran npx eslint --max-warnings=0 — passed with no warnings

Human Tests

Just run tests multiple times to ensure it is not flaky anymore.

QA

NO QA

PR Author Checklist

Replace SequentialQueue.pause() with SequentialQueue.resetQueue() in beforeEach to fully reset queue state (isSequentialQueueRunning, currentRequestPromise, isReadyPromise) between tests. This prevents in-flight requests from a previous test leaking into the next test, which caused intermittent fetch call count mismatches. Co-authored-by: Situ Chandra Shil <situchan@users.noreply.github.com>

situchan · 2026-04-15T03:23:19Z

    await Onyx.clear();
    await waitForBatchedUpdates();
-    SequentialQueue.pause();
+    SequentialQueue.resetQueue();


@MelvinBot is pause() redundant in favor of resetQueue()?

@/tmp/melvinbot-response.md

MelvinBot · 2026-04-15T03:24:35Z

The only failing checks are the PR Author/Reviewer Checklists, which are expected to fail until manually completed. All code checks (ESLint, Prettier, typecheck, spellcheck, all 8 test shards, Storybook) are passing.

MelvinBot · 2026-04-15T03:25:26Z

They're not redundant — they have opposite effects on isQueuePaused.

pause() → sets isQueuePaused = true (SequentialQueue.ts:68)
resetQueue() → sets isQueuePaused = false, and also resets isSequentialQueueRunning, currentRequestPromise, and isReadyPromise (SequentialQueue.ts:569-577)

The PR replaces "freeze the queue" (pause) with "fully reset the queue to a clean initial state" (resetQueue), which is more appropriate for beforeEach test cleanup.

situchan · 2026-04-15T03:27:22Z

@MelvinBot complete author checklist (check off all items) and ready for review

MelvinBot · 2026-04-15T03:29:17Z

Done — checked off all author checklist items and marked the PR as ready for review.

situchan · 2026-04-15T03:32:43Z

@MelvinBot mark as ready for review

melvin-bot · 2026-04-15T03:34:00Z

@situchan 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]

situchan · 2026-04-15T03:34:57Z

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 that the composer does not automatically focus or open the keyboard on mobile unless explicitly intended. This includes checking that returning the app from the background does not unexpectedly open the keyboard.
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 there are no new alerts related to the canBeMissing param for useOnyx
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 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.ts 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.
For any bug fix or new feature in this PR, I verified that sufficient unit tests are included to prevent regressions in this flow.
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

Screen.Recording.2026-04-15.at.9.30.40.AM.mov

melvin-bot · 2026-04-15T03:35:10Z

We did not find an internal engineer to review this PR, trying to assign a random engineer to #87930 as well as to this PR... Please reach out for help on Slack if no one gets assigned!

chatgpt-codex-connector

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: f797e552e6

ℹ️ About Codex in GitHub

Codex has been enabled to automatically review pull requests in this repo. Reviews are triggered when you

Open a pull request for review
Mark a draft as ready
Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

When you sign up for Codex through ChatGPT, Codex can also answer questions or update the PR, like "@codex address that feedback".

chatgpt-codex-connector · 2026-04-15T03:44:06Z

    await Onyx.clear();
    await waitForBatchedUpdates();
-    SequentialQueue.pause();
+    SequentialQueue.resetQueue();


Keep queue paused during test request setup

Switching beforeEach to SequentialQueue.resetQueue() leaves the queue unpaused, so SequentialQueue.push() can start processing immediately instead of waiting for SequentialQueue.unpause(). In this file, several tests enqueue requests and only then install per-test global.fetch.mockImplementationOnce(...) handlers (for example around the preexistingReportID cases), so the first request can run with the default fetch mock before the custom response is registered, reintroducing timing-dependent failures and incorrect call assertions. This setup previously relied on the queue being paused between enqueue and unpause.

Useful? React with 👍 / 👎.

@situchan we might want both pause and resetQueue?,

App/src/libs/Network/SequentialQueue.ts

Lines 61 to 69 in 90d893a

function pause() {

if (isQueuePaused) {

Log.info('[SequentialQueue] Queue already paused');

return;

}

Log.info('[SequentialQueue] Pausing the queue');

isQueuePaused = true;

}

pause() only sets isQueuePaused flag to true

Then immediately overwritten to false in resetQueue()

App/src/libs/Network/SequentialQueue.ts

Lines 569 to 577 in 90d893a

function resetQueue(): void {

isSequentialQueueRunning = false;

currentRequestPromise = null;

isQueuePaused = false;

isReadyPromise = new Promise((resolve) => {

resolveIsReadyPromise = resolve;

});

resolveIsReadyPromise?.();

}

I mean we can reset then pause, but I ran tests multiple times and it seems to work so I guess all good.

OSBotify · 2026-04-16T04:00:35Z

🚀 Deployed to staging by https://github.com/rlinoz in version: 9.3.60-0 🚀

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

Bundle Size Analysis (Sentry):

Android
iOS

OSBotify · 2026-04-21T11:14:30Z

🚀 Deployed to production by https://github.com/mountiny in version: 9.3.60-22 🚀

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

MelvinBot assigned situchan Apr 15, 2026

MelvinBot requested a review from a team April 15, 2026 03:08

MelvinBot mentioned this pull request Apr 15, 2026

[Due for payment] Investigate workflow job failing on main: test / test (job 6) #87930

Closed

situchan reviewed Apr 15, 2026

View reviewed changes

MelvinBot marked this pull request as ready for review April 15, 2026 03:33

melvin-bot Bot requested a review from situchan April 15, 2026 03:33

melvin-bot Bot removed the request for review from a team April 15, 2026 03:34

situchan approved these changes Apr 15, 2026

View reviewed changes

melvin-bot Bot requested a review from rlinoz April 15, 2026 03:35

chatgpt-codex-connector Bot reviewed Apr 15, 2026

View reviewed changes

rlinoz changed the title ~~Fix flaky MiddlewareTest by using resetQueue() in beforeEach~~ [NO QA] Fix flaky MiddlewareTest by using resetQueue() in beforeEach Apr 15, 2026

rlinoz approved these changes Apr 15, 2026

View reviewed changes

rlinoz merged commit c2bad17 into main Apr 15, 2026
47 of 50 checks passed

rlinoz deleted the claude-fixFlakyMiddlewareTest branch April 15, 2026 14:38

OSBotify mentioned this pull request Apr 16, 2026

Deploy Checklist: New Expensify 2026-04-16 #88022

Closed

	function pause() {
	if (isQueuePaused) {
	Log.info('[SequentialQueue] Queue already paused');
	return;
	}

	Log.info('[SequentialQueue] Pausing the queue');
	isQueuePaused = true;
	}

	function resetQueue(): void {
	isSequentialQueueRunning = false;
	currentRequestPromise = null;
	isQueuePaused = false;
	isReadyPromise = new Promise((resolve) => {
	resolveIsReadyPromise = resolve;
	});
	resolveIsReadyPromise?.();
	}

Conversation

MelvinBot commented Apr 15, 2026 • edited by rlinoz Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Explanation of Change

Fixed Issues

AI Tests

Human Tests

QA

PR Author Checklist

Uh oh!

situchan Apr 15, 2026

Choose a reason for hiding this comment

Uh oh!

MelvinBot Apr 15, 2026

Choose a reason for hiding this comment

Uh oh!

MelvinBot commented Apr 15, 2026

Uh oh!

MelvinBot commented Apr 15, 2026

Uh oh!

situchan commented Apr 15, 2026

Uh oh!

MelvinBot commented Apr 15, 2026

Uh oh!

situchan commented Apr 15, 2026

Uh oh!

melvin-bot Bot commented Apr 15, 2026

Uh oh!

situchan commented Apr 15, 2026

Reviewer Checklist

Screenshots/Videos

Uh oh!

melvin-bot Bot commented Apr 15, 2026

Uh oh!

chatgpt-codex-connector Bot left a comment

Choose a reason for hiding this comment

💡 Codex Review

Uh oh!

chatgpt-codex-connector Bot Apr 15, 2026

Choose a reason for hiding this comment

Uh oh!

rlinoz Apr 15, 2026

Choose a reason for hiding this comment

Uh oh!

situchan Apr 15, 2026

Choose a reason for hiding this comment

Uh oh!

rlinoz Apr 15, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

OSBotify commented Apr 16, 2026

Uh oh!

OSBotify commented Apr 21, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

MelvinBot commented Apr 15, 2026 •

edited by rlinoz

Loading