The current code is a whole lot of first pass "get the code modular" decisions, with a build system approach that no longer makes sense given the advances in tooling for offline JavaScript.

Estimated as a long-running task, the following subtasks can be identified:

• rewrite to proper commonjs2 format (taking advantage of the requires-are-cached property)
• add in eslint for code and code style validation
• rewrite to ES6+ as much as possible
• do bundling with webpack
• set up code testing using something like mocha or jest

A possible rewrite for the parser side of things might also be worth it, using java-parser to convert a set of .pde files into a single large file (the same way Processing itself loads all code as source inside a single PApplet class definition) that is then turned into an AST, which can then either be serialized as javascript source, or compiled into a javascript sketch object (the latter being the preferred choice as this would allow live-updates much better).