Code formatting is a practice of restructuring source code without changing its AST in order to increase readability and/or to make the code look better.
When I choose a formatter for my code, I wish for the following features:
As configuration-free as possible. I don't want to tell the formatter how I like my code, I like the rules enforced from elsewhere.
As easy to execute as possible. In ideal cases — a single command.
As simple and fast as possible. I want the formatter to have little dependencies and to work quickly.
As popular as possible. I want the formatter to have a user base; this will also ensure that the formatter will stay maintained.