Release Candidate: 4.0.0

There were a number of bugs in the 3.x releases relating to how escape sequences were handled.

We took a step back and thought through these issues and decided that the best course was to change our public API in some subtle but important ways. The new API means that users don't have to worry about escape sequences anymore. By default, the selector parser always returns unescaped strings and then re-escapes them when converting back to CSS strings, using the originally authored escape sequences if possible. If you didn't handle escape sequences or deal with quoted values in attribute selectors, then this release is probably just fixing bugs that you didn't know you had.

If you are manipulating selectors with nonstandard CSS syntax, escape sequences, or special characters, this new API means your code is going to need to change.

There is a full writeup of the changes here: #133