Darkness Activated Tiles is a module for the virtual tabletop FoundryVTT, which allows you to play games like Dungeons & Dragons online. This module is written in JavaScript and it has close to 100 thousand downloads. It's function is to show and hide things on the canvas based off of the light level of the canvas. This project was more of a challenge than I anticipated because it was difficult to learn the API for FoundryVTT which was badly documented and had no type hinting since it was written in JS, a dynamically typed language. I wasn't afforded any of the IDE luxuries of a statically typed language making navigating the codebase a real pain.