asar target and prepackaged option support for it

[pauliusuza]

• electron-builder 11.2.3:

• OSX:

Builder crashes when trying to package app with --prepackaged command with the following error:

Error: ENOENT: no such file or directory, 
open '/Users/pro/repository/desktop_app/dist/mac/Desktop.app/Contents/Resources/app-update.yml'
at /Users/pro/repository/desktop_app/node_modules/electron-builder/src/macPackager.ts:101:13

In my package.json:
{"dist": "npm run compile && build --prepackaged ./asar"}
where ./asar is the folder containing app.asar, core.asar and node_modules.asar files

What I want is to be able to point electron-builder into a folder containing app.asar and it would package the apps for distribution.

[develar]

@pauliusuza Crash fixed. But prepackaged is not for your use case. @wojtkowiak Could you please share your experience — how do you use already packed asar files?

[pauliusuza]

So I found a temporary workaround by packing app.asar through the electron-builder, and including the remaining .asar files through extraResources key:

"build": {
    "asar": true,
    "files": [
      "!**",
      "index.js",
      "package.json"
    ],
    "extraResources": [
      {
        "from": "asar",
        "to": ""
      }
    ]
}

However, it would be really great if electron builder would have a feature which would simply pack the whole folder and it's contents if it has app.asar file without running additional checks.

build --fromAsar ./path/to/folder/containing/app.asar_file/

Would you consider adding this feature?

[develar]

@pauliusuza It is already supported (#759)

without running additional checks

What error do you get?

[wojtkowiak]

I am not sure what this problem is actually about.
@pauliusuza if you are packing your app to asars yourself you just need to turn off asar packing in electron-builder, the rest should work. I am using electron-builder programmatically so I am just setting asar to false in build options. @develar is there a cli switch for that?

[pauliusuza]

@develar it's checking for package.json and index.js files, so if I simply point it to a folder with asar files the build step fails.

[develar]

@pauliusuza So — you have some folder where asar files are located (app.asar is required, no other electron files) and just want to pack it into .app or .dmg or any other electron-buidler target?

Just curious — why electron-builder is not suitable to produce required asar files?

[pauliusuza]

@develar yes. Mostly for flexibility - we want to separate the build process and packaging process. Asar files would be built in one CI process (which is complex and takes more time) and stored on a cdn, and packaging would run in another process on demand.

We have a use case where we need to be able to build 20-30 different apps on demand on CI re-using same .asar files, but only changing app name and branding.

[develar]

Asar files would be built in one CI process

Using electron-builder? Or using asar tool programmatically? I just want to understand to be sure that implemented solution will be the best solution (not workaround).

[pauliusuza]

Sure, thanks.

1. The first step of the process would be running asar tool programmatically (through gulp or npm script) and pack the required files into .asar archives, it would then store those .asar files into a CDN. This would run on CI on each commit.

2. Second step would be executed on demand. It would fetch the latest .asar files from CDN, store them into a folder, apply required customization / branding, and run electron builder to pack all of this into a distributable format.

[develar]

Got it. So:

1. New target asar will be added. electron-builder will just pack your app into app.asar.
2. --prepackaged will detect — is it fully prepackaged directory (has electron files) or not.

[pauliusuza]

@develar thanks, that sounds good

[pauliusuza]

So just a note for --prepackaged /dir
If app.asar already exists in the /dir, then it should check for existence of the package.json and index.js files inside the app.asar file, and not in the /dir folder itself.