The setup was simple and smooth. The readme is very clear in terms of setup and structure. However, it's not very clear how to interpret the input and how to actually return the wanted result. I had to check further eslint documentation and do a bit of guessing to find the right methods quickly.
Since I'm used to working with Typescript, I do miss having types, easier access to documentation and errors while typing. I also resisted the temptation to convert it to ES6 and I followed the same coding style. Fun fact: in the README, 'e2e' is written as '2e2'