App hangs when loading on web/desktop due to infinite loop

[tgolen]

Problem

For some people (@joekaufmanexpensify @luacmartins) when they load App, the code goes into a seemingly infinite loop that hangs the browser for a long time.

Why is this important?

It makes the app unusable

Solution

Determine what is causing the loop and find a way to fix it

[tgolen]

I am able to determine that the long loop happens here:

App/src/libs/actions/Report.js

Line 446 in 47ec8f4

.then(details => configureReportNameAndIcons(simplifiedReportsList, details));

The method PersonalDetails.getFromReportParticipants(simplifiedReportsList) is called once, but the method inside of .then() is called repeatedly over and over again in this loop.

This code was recently refactored in #7453 so the first step I am going to do is revert that PR to see if the problem clears up, then we can go from there. I suspect it has something to do with the addition of getFromReportParticipants() returning a Promise.

cc @sobitneupane

[sobitneupane]

I am able to determine that the long loop happens here:

App/src/libs/actions/Report.js

Line 446 in 47ec8f4

.then(details => configureReportNameAndIcons(simplifiedReportsList, details));

The method PersonalDetails.getFromReportParticipants(simplifiedReportsList) is called once, but the method inside of .then() is called repeatedly over and over again in this loop.

This code was recently refactored in #7453 so the first step I am going to do is revert that PR to see if the problem clears up, then we can go from there. I suspect it has something to do with the addition of getFromReportParticipants() returning a Promise.

cc @sobitneupane

I was also facing similar issue few hours back. But My branch does not have changes from #7453.

[luacmartins]

@sobitneupane can you reproduce this on dev? I only see this issue on production.

[sobitneupane]

I am not having the issue now. But before in incognito window I was stuck in login page. After I entered email and pressed continue. Continue sign was loading forever.
In non-incognito window, there was loading sign in the middle and nothing was happening.

But I was able to use the app with 127.0.0.1 instead of localhost.

[luacmartins]

That seems to be a different issue. My login pages work fine, but the app hangs when I'm already logged in and it refreshes.

[tgolen]

Thanks for the info! I think I have yet to determine that this change is 100% the root cause, but at least it's as far as I could trace the problem to for now. With it being reverted, I'm hoping it will point me toward the next place.

[tgolen]

Picking this back up today and making progress.