Integrate an option to explorer context menu with Electron

This question is not actually related to Electron. It can be divided into two parts:

1. Creating custom dynamic context menu entries during installation passing the respective selected file as command line argument to its target
2. Node.js command line argument parsing

Creating custom dynamic context menu entries during installation

Windows:

• Adding context menu entries during installation using WiX
• Since it boils down to adding registry keys, this more general SO post about adding context menu entries for specific file types may also interest you.

OSX:

• I really can't tell.

Node.js command line argument parsing

Multiple options exist for command line argument parsing in Node.js, here is just a handful I've been using in the past:

• Minimist
• command-line-args
• and my current favourite, Yargs

For the OS X / macOS case, one (the?) way is to make a service (in ~/Library/Services/ or /System/Library/Services/) that can receive the folder item(s) in question.

(Footnote 1: Note that services can be individually enabled/disabled in System Preferences, and the whole experience seems a little bit buggy during development sometimes.)

(Footnote 2: I've only done this via the Automator but I hope at least it gives you some pointer as to where to get started.)