Prettier 2.0 – 2.0 2020

Problem

We already have a Prettier 2.0 issue – #3503 – but tell you what: Time’s up for that one. As of this writing, Node.js 8 is scheduled to expire early on December 31, 2019. And we still support Node.js 4. In two months we will be 6 versions behind! Supporting Node.js 4 and Node.js 6 has been a real hassle lately as our dependencies (rightfully!) has stopped supporting them. We have spent a lot of unnecessary time getting tests to pass in Node.js 4. So here’s my suggestion for a 2.0 of a Prettier 2.0 issue: The main focus should be dropping support for unsupported Node.js versions. Let’s aim for releasing Prettier 2.0 early in January 2020 with support for only Node.js 10+. Apart from that we could do some easy breaking changes: - Change the default for `trailingComma` to `es5`, as discussed in the original Prettier 2.0 thread. - Remove deprecated stuff. When that is done – if we have time, we could do more things. We’ll see. For example, it would be really nice addressing #5588 (making all unsafe template literal formatting opt-in). I also have a suggestion for lots of improvements for Prettier’s CLI and API, but I’ll open a separate issue for that. /cc @prettier/core @brodybits @fisker