ASAR problem in Electron

[markkovacs76]

If node-tar is used in Electron environment where asar file support is enabled, the entry names with extension asar will not be written correctly, because Electron uses its own 'fs' library which handles asar files as a sub-directory.
Hence, Electron does offer 'original-fs' library if you want to use asar file as normal file instead of a virtual sub-directory in the modified 'fs'.
It would be good if node-tar supported the 'original-fs' library by demand instead of 'fs' from electron.

[isaacs]

I'm not sure what the feature request is here. What would the interface look like, and how would it behave?

[dashart-ke]

I ran into a similar issue today:
In my electron based application, I tried to extract a tar.gz archive, which is contains an electron application.

After extraction, the following file:
ELECTRON_APP_NAME.app/Contents/Resources/app.asar
is missing in target directory:

The log (verbose) reports, it would extract 'app.asar':
...
Extracting: ELECTRON_APP_NAME.app/Contents/Resources/nb.lproj/
Extracting: ELECTRON_APP_NAME.app/Contents/Resources/app.asar
Extracting: ELECTRON_APP_NAME.app/Contents/Resources/am.lproj/
...

This looks like an internal side effect of special electron fs behavior, which will treat app.asar like a regular directory
https://www.electronjs.org/docs/latest/tutorial/asar-archives#treating-an-asar-archive-as-a-normal-file

[isaacs]

@dashart-ke ok, so, same question I asked @markkovacs76: what do you want tar to do about it?

[markkovacs76]

Either you could add an extra option for tar.x to use original-fs instead of fs library. In this case the user should import fs-original and append the reference to the options.

Or in the source in node-tar the electron could be detected:

if (typeof process !== 'undefined' && typeof process.versions === 'object' && !!process.versions.electron) {
        return true;
}

If yes, import fs from 'node:fs' in your code should be import fs from 'original-fs'.

Or, I just found the easiest solution. In Electron I found
process.noAsar = true
But this approach could be used outside the library, before e.g. the tar.x is called and afterwards this should be set to false again if needed.

[isaacs]

So the feature request is to have a fs option, which defaults to import * as fs from 'node:fs', that you can pass your own fs implementation into?

Seems fine to me. Just a pain to go through and make the edits. But patch welcome.