Rbfmt is a yet another Ruby code formatter written in Rust, based on the Ruby's official Prism parser.

# a.rb
foo . bar(1,2  3 # 4
  )

$ rbfmt a.rb
# a.rb
foo.bar(
  1,
  2,
  3 # 4
)

$ cargo install rbfmt

You can configure formatting via .rbfmt.yml file.

Available values and defaults:

format:
  line_width: 100