The Euler layout is an open source project, and we greatly appreciate any and all contributions.
This layout will either be bundled with Cytoscape.js itself or Babel will be added to this project. That means that modern ES2015/ES6 language features can be used.
If you'd like to contribute code to Cytoscape.js but you're not sure exactly what you'd like to implement, take a look at our current milestones to see what features we have planned in future --- or anything labelled help-wanted. Of course, we also welcome your own ideas.
Submit issues or feature requests to the issue tracker.
If you're submitting a bug report, clearly describe the issue. List the steps necessary to reproduce your issue along with the corresponding code (preferably a JSBin, as that makes the issue less ambiguous and much faster to fix).
Make certain to mention the version (or commit hash) of the library you are using and version of the browser/environment you are using.
To propose a change, fork the repo, make a change, and then submit a pull request so that the proposed changes can be reviewed.
Use two spaces for indentation, and single-quoted strings are preferred. The main thing is to try to keep your code neat and similarly formatted as the rest of the code. There isn't a strict styleguide.
You can test the layout with the demo.html page. If you have other datasets to test with, copy demo.html (with a name like demo-foobar.html) and embed your data in the new file.