Wrong $0 in bundled electron app

[acromarco]

We have an election app that is bundled to an .exe file.

A command line like
bundled.exe -f filename
will result in:
{ _: ['filename'], '$0': 'bundled.exe -f' }

The following workaround:
const argv = yargs.parse(process.argv.slice(1));
will result in
{ _: [], f: 'filename', '$0': 'bundled.exe -f' }

Please notice that the $0 ist still wrong because it contains the "-f".

If this an expected behavior? Is there a way to work around it?

[zinwalin]

same issue here.

[bcoe]

@zinwalin @acromarco does this continue to be an issue? I wonder if we could detect we're in an electron environment and potentially handle our slicing a bit differently.

[shadowspawn]

I was looking into this in weekend (in context of Commander).

References:

• process.argv differs in built electron apps electron/electron#4690 (comment)
• Commander incorrectly assumes that process.argv[0] is 'nodejs' and argv[1] is script name tj/commander.js#512

Still a WIP, detection:

    if (process.versions && process.versions.electron) {
      parseOptions.from = 'electron';
    }

and decision about where to slice:

    case 'electron':
      if (process.defaultApp) {
        userArgs = argv.slice(2);
      } else {
        userArgs = argv.slice(1);
      }
      break;

[mleguen]

@shadowspawn This would indeed solve the first half of this issue (slice(1) needed instead of slice(2)).

However, @acromarco also reported that it first flag (-f) was merged with the exe name into req.argv[0].

Is is something you can reproduce too?

[shadowspawn]

-f merged: no, I didn't investigate that aspect.

[mleguen]

@shadowspawn The master branch should now be OK for your use case (ie slice(2)replaced by slice(1) if process.defaultApp is false). Would you please mind testing?

@zinwalin @acromarco Could one of you please give us some feedback about the 2nd point ("notice that the $0 ist still wrong because it contains the "-f") reported in the initial issue?

[shadowspawn]

(Disclaimer: I do not currently use yargs or electron for real, just an interested third party!)

1. the slice issue does not appear to be fixed on master

From experimentation process.defaultApp is undefined or true, but not false. So the test for strict equality against false is not working as intended currently:

yargs/lib/process-argv.js

Line 5 in a8ce123

if (process.defaultApp === false) return 0

2. I am not seeing the -f problem. Testing on macOS.

console.log(process.defaultApp);
console.log(args);
const argv = require('yargs').argv;
console.log(argv);

# Calling electron directly
% ./node_modules/.bin/electron . -f filename                                                     master
true
[
  '/Users/john/Documents/Sandpits/commander/issues/electron-quick-start/node_modules/electron/dist/Electron.app/Contents/MacOS/Electron',
  '.',
  '-f',
  'filename'
]
{
  _: [],
  f: 'filename',
  '$0': 'node_modules/electron/dist/Electron.app/Contents/MacOS/Electron'
}

# Running bundled app
% ./foo-darwin-x64/foo.app/Contents/MacOS/foo -f filename                                        master
undefined
[
  '/Users/john/Documents/Sandpits/commander/issues/electron-quick-start/foo-darwin-x64/foo.app/Contents/MacOS/foo',
  '-f',
  'filename'
]
{
  _: [ 'filename' ],
  '$0': 'foo-darwin-x64/foo.app/Contents/MacOS/foo'
}

[bcoe]

@shadowspawn @mleguen reading the issue linked, it sounds like they were suggesting only slicing at 0 when we know the electron app is bundled, via, process.defaultApp === false? might be worth asking for clarification from the electron folks?

[shadowspawn]

I tracked down the supporting docs:

• https://github.com/electron/electron/blob/master/docs/api/process.md#processdefaultapp-readonly

process.defaultApp Readonly

A Boolean. When app is started by being passed as parameter to the default app, this property is true in the main process, otherwise it is undefined.

[bcoe]

@zcbenz @MarshallOfSound, recommendation on how we should best detect a argv.slice(0) vs., argv.slice(1), such that we get the bin correct?

should we be checking for process.defaultApp === true?

[zcbenz]

@bcoe Checking process.defaultApp is currently the only way to handle this.

[mleguen]

@shadowspawn Thanks for the tests, and pointing to the doc.

So I am going to replace my (process.defaultApp === false) by (!!process.version.electron && !process.defaultApp), which will lead to:

• slice(1) only if process.version.electron is defined (this is an electron app) and process.defaultApp is undefined (the app was not launched by passing a parameter to electron)
• slice(2) if process.version.electron is undefined (this is not an electron app) or process.defaultApp is true (the app was launched by passing a parameter to electron)

EDIT: checking !process.defaultApp alone is of course not enough, so we have to combine it with process.versions.electron. See the doc for process.versions.electron

2nd EDIT: nothing wrong in electron's doc as I initialy stated: process.defaultApp is indeed a boolean. Maybe time to take a break?

[mleguen]

@shadowspawn 2nd fixed merged into master: ready for testing, if you don't mind.

[shadowspawn]

Working fine now in my tests, args getting sliced at correct point.

[bcoe]

@shadowspawn thanks for helping to sort this out.