js2crx.py

Converts a Javascript userscript (.user.js) into a chrome extension (.crx)

Required software

python – versions 2.x or 3.x should both work
ffmpeg & ffprobe – for icon creation
chrome – for .crx compilation

Downloads

js2crx.py / download – main python application
build.bat / download – template build script

Command line usage

js2crx.py is mainly designed as a command line application. It includes a template Windows batch script build.bat which can be easily edited to auto-build a project. Simply edit the EDIT_THIS parts in it.

Arguments are passed into js2crx.py using short (-v) or verbose (--version) flags. Executing js2crx.py --usage will list the available flags, their aliases, and a short description. Reading build.bat also helps.

Library import usage

js2crx.py should also be able to be imported as a library and executed in a similar manner to the command line version. This is untested/undocumented, but there's no real reason why it shouldn't work. If this functionality is required, reading through js2crx.py's main should give some insight.

Userscript metadata

Typical userscript files contain a metadata block at the top of the file. To specify additional info for building the .crx file, an additional ==ChromeExtension== metadata block should follow it. For example:

// ==ChromeExtension==
// @permission   storage
// @icon-size    16:bilinear
// @icon-size    32:bilinear
// @icon-size    128:neighbor
// @require      additional_javascript.js
// @resource     resource_filename.html
// @update-url   https://example.com/userscript.update.xml
// @download-url https://example.com/userscript.crx
// ==/ChromeExtension==

The following tags are allowed:

@permission value (multiple allowed)
A chrome extension permission.
@icon-size size[:resizer] (multiple allowed)
An icon size integer, followed by an optional ffmpeg scaler. These are used to auto-generate icons from the existing userscript icon.
@require javascript_file (multiple allowed)
A local path (relative to the location of the initial .user.js script) to an additional Javascript file.
This should be used if the ==UserScript== block contains any @require tags.
@resource filename (multiple allowed)
A local path (relative to the location of the initial .user.js script) to an additional resource file.
This should be used if the ==UserScript== block contains any @resource tags.
@update-url url
A URL to the update.xml file generated by js2crx.py.
@download-url url
A URL to the extension.crx file generated by js2crx.py.