Set up a CLI script that prettifies the entire code base. Developers and scripts can run this script whenever they made changes and are unsure whether there are formatting issues. This removes a large amount of edge cases. Prettier makes this easy:
prettier --write .
Examples for such tasks could be npm run format, make format, etc.
While you are at it, extend this script to run all the tools
that you use to keep your code base in a good shape. An example are linters,
which can often also auto-correct certain issues they find. A better name for
such a script might be fix instead of format.