Restoring the process variable in the browser.

[ccheraa]

Bug Description:

Up until a recent version, Theia used to use webpack 4, which had polyfills for some node packages, including process.
After upgrading to webpack 5, which dropped the support for those polyfills, a bug surfaced when running Theia browser IDE in an Electron window.
Theia tries to access the process variable which no longer exists, and throws an exception that stops the IDE from even starting up.
It happens in:

theia/packages/filesystem/src/browser/filesystem-preferences.ts

Line 32 in dece352

export const MAX_FILE_SIZE_MB = environment.electron.is() ? process.arch === 'ia32' ? WIN32_MAX_FILE_SIZE_MB : GENERAL_MAX_FILE_SIZE_MB : 32;

Steps to Reproduce:

1. Build the browser IDE.
2. Browse to its url in an Electron window

Additional Information

I have mentioned this bug before with a work around for Cypress, in #9751
We managed to fix it by including the process variable again using Webpack Config file.
Check evolvedbinary/fusion-studio-extension#472
I think this should be included in the changelog/migration guide.

• Theia Version: 1.15.0

[adamretter]

CC @duncdrum @marmoure

[vince-fugnitto]

@ccheraa I added a general entry about webpack in the draft migration guide (#9817).

I don't think we should be specific in the guide to include the update mentioned in the issue as running the browser instance in electron is not a standard or supported use-case by the framework. It's also virtually impossible for the framework to anticipate some of the things that downstream applications might do or perform like this use-case.

[ccheraa]

I know it's not a standard use-case, yet it showed that the process variable, is not always present when the app is run on Electron.
I believe, at least this should be addressed, and fixed.
As far as I know, that's the only instance of the problem:

theia/packages/filesystem/src/browser/filesystem-preferences.ts

Line 32 in dece352

export const MAX_FILE_SIZE_MB = environment.electron.is() ? process.arch === 'ia32' ? WIN32_MAX_FILE_SIZE_MB : GENERAL_MAX_FILE_SIZE_MB : 32;

I actually think that using the process variable only when it should exist is better than providing it where it shouldn't be available, which sounds like a waorkaround.

[vince-fugnitto]

I know it's not a standard use-case, yet it showed that the process variable, is not always present when the app is run on Electron. I believe, at least this should be addressed, and fixed.

@ccheraa if you believe it is something to be fixed in the framework, please feel free to contribute a pull-request 👍