Use refmt to format your Reason code in Atom.
No default keybindings are provided, but they can be configured in your keymap.
||Format the active file|
||Convert an OCaml file to a Reason file|
||Convert a Reason file to an OCaml file|
apm install language-reason reason-refmt ocaml-merlin linter
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.