exclude files from build in electron via package.json

Question

I am trying to build an electron app and during build creation exclude some files and folders. I read similar topics and also bug thread on github but still cannot make it properly.

Final goal is to exclude all files with extension .py and folder named tests and all its subfolders.

However even simple example with one file with explicit name does not work. Can you please point me to my mistake? Here is package.json

{
  "name": "Build-Downloader",
  "version": "0.1.0",
  "main": "electron_main_win.js",
  "scripts": {
    "start": "electron ."
  },
  "dependencies": {
    "axios": "^0.19.2",
    "python-shell": "^1.0.8"
  },
  "build": {
    "files": [
      "!electron_backend.py"
    ]
  }
}

and the command line I use to compile my package:

electron-packager  ./ --platform=win32 --arch=x64 --electron-version=8.2.3  --out=electron_build --overwrite

Answer 1

Finally I found a solution on my own. I have already thrown a big stone to myself due to my stupidity :)

However I would like to share my knowledge in case somebody will need this info.

electron-packager supports only --ignore command line arguments with RegEx

Note: you may use as many ignores as you want

Note2: do not mix names electron-packager and electron-builder, builder supports package.json :)

So finally ultimate solution was:

electron-packager  ./ --platform=win32 --arch=x64 --electron-version=8.2.3  --out=electron_build --overwrite --ignore="^.*\.py" --ignore="\/node_modules" --ignore="\/tests"