Birth of Prettier

Summary

React Conf is around the corner and it's been almost 10 years since Prettier was released. I figured it would be a good time to recount the journey from its early days to now. This is the story of how the "Space vs Tabs Holy War" ended, not through one side winning over the other but instead a technological invention making it the underlying source of tensions no longer being a thing. Back Story School time In order to understand my state of mind when I worked on Prettier, we need to go back in time when I did my college at EPITA, a French school dedicated to Computer Science. When you start, you are given a PDF with the list of formatting rules you need to obey when turning your coding assignments. Not following them is extremely punishing where for each failure you are losing 2 points out of a grade over 20. So 10 formatting issues and you're getting a 0! This taught people the hard way that they need to train themselves to format their code properly. As you can expect, I tried to code my way out of this and implement such a linter with fixers myself so that I wouldn't have to deal with it. But it turns out that writing what is commonly called a linter + formatter for the C programming language was way out of my depth for a first year student. So I ended up learning these formatting rules but it engraved in the back of my mind the need for a way to solve this problem automatically. Facebook time A few years later, I joined Facebook and my first interaction with an awesome engineer there included a bunch of formatting style changes. Turns out the guidelines I learned at school was not the same ones that Facebook was using. It felt like a pretty bad setup for everyone involved. Yuan Tian had to spend her valuable time going through all my code and pointing out all the formatting issues (eslint wasn't yet created!). I then had to go back and fix everything. At first I thought this was pointless but then a few months later a new person joined the team and I found myse...