How can I add a custom formatter that will be picked up by doom-emacs' format ((format +onsave)) module?
I want to run the erlfmt program on save when editing Erlang files, but I'm not sure how I should configure that.
Doom seems to be using https://github.com/lassik/emacs-format-all-the-code under the hood, so I tried adding the following to config.el:
(define-format-all-formatter erlfm
(:executable "erlfm")
(:install (macos "brew install erlfmt"))
(:languages "Erlang"
(:format (format-all--buffer-easy executable "-")))
However, this just gives me the error “Don't know how to format erlang-mode code” when I run format-all-buffer. (I get the same error if I change to :languages "erlang-mode".)