fix: relaxed condition to check if resource exists

[kittaakos]

Motivation

To open built-in examples from an AppImage.

Change description

Relaxed the condition to check if a resource exists.
The original (fs-extra-based) implementation did not check if the file is writable either.
Resources are not writable in mounted AppImages.

Other information

Closes #1586

Reviewer checklist

• PR addresses a single concern.
• The PR has no duplicates (please search among the Pull Requests before creating one)
• PR title and description are properly filled.
• Docs have been added / updated (for bug fixes / features)

[per1234]

I verified this fixes #1586 for the Linux AppImage package.

Thanks Akos!

I was never able to reproduce #1586 with the Linux ZIP package, so I can't verify it fixes the reported problem as it applies to that package. I do suspect that the cause was the same (e.g., perhaps there is a way to run the IDE from inside the ZIP package without extracting the archive?), and therefore will also be fixed by this PR.

[kittaakos]

I was never able to reproduce #1586 with the Linux ZIP package,

Me neither, but I thought it was an app image issue. Has anybody had the same issue with the ZIP?

so I can't verify it fixes the reported problem as it applies to that package. I do suspect that the cause was the same (e.g., perhaps there is a way to run the IDE from inside the ZIP package without extracting the archive?), and therefore will also be fixed by this PR.

I learned this the hard way. If the app image is started, the AppDir is mounted read-only. If you start the ZIP image, the contained resources (such as the built-ins) are resolved with the absolute FS path instead of the mounted one. From here:

root INFO cloneExample file:///tmp/.mount_arduin6hMpJz/resources/app/node_modules/arduino-ide-extension/Examples/01.Basics/AnalogReadSerial

VS

root INFO cloneExample file:///home/parallels/Desktop/dev/arduino-ide/electron/build/dist/linux-unpacked/resources/app/node_modules/arduino-ide-extension/Examples/01.Basics/AnalogReadSerial

Since it was read-only, the exists logic gave a false negative result, so the built-in sketch creations failed with the sketch does not exist error when IDE2 was started as an app image.

[per1234]

Has anybody had the same issue with the ZIP?

Yes, the original reporter:

#1586 (comment)

@per1234 you changed my report to add the line:

The bug does not occur when using the ZIP package of the IDE.

but this is incorrect. ALL of my testing was done with the zip package. I never tested with the appimage

[kittaakos]

OP of #1586 has confirmed that it worked with the ZIP. So only the AppImage was affected. I am removing the on hold label.

[AlbyIanna]

Neat! Code is 👍