treefmt/docs/formatters.md

A list of known formatters

Here is a list of all the formatters we tested. Feel free to send a PR to add other ones!

prettier

An opinionated code formatter that supports many languages.

command = "prettier"
options = ["--write"]
includes = [
    "*.css",
    "*.html",
    "*.js",
    "*.json",
    "*.jsx",
    "*.md",
    "*.mdx",
    "*.scss",
    "*.ts",
    "*.yaml",
]

Black

A python formatter.

command = "black"
includes = ["*.py"]

clang-format

A tool to format C/C++/Java/JavaScript/Objective-C/Protobuf/C# code.

command = "clang-format"
options = [ "-i" ]
includes = [ "*.c", "*.cpp", "*.cc", "*.h", "*.hpp" ]

Note: This example focuses on C/C++ but can be modified to use with other languages.

Elm

command = "elm-format"
options = ["--yes"]
includes = ["*.elm"]

Go

command = "gofmt"
options = ["-w"]
includes = ["*.go"]

Ormolu

Haskell formatter. Make sure to use ormolu 0.1.4.0+ as older versions don't adhere to the spec.

command = "ormolu"
options = [
    "--ghc-opt", "-XBangPatterns",
    "--ghc-opt", "-XPatternSynonyms",
    "--ghc-opt", "-XTypeApplications",
    "--mode", "inplace",
    "--check-idempotence",
]
includes = ["*.hs"]

stylish-haskell

Another Haskell formatter.

command = "stylish-haskell"
options = [ "--inplace" ]
includes = [ "*.hs" ]

nixpkgs-fmt

Nix code formatter.

command = "nixpkgs-fmt"
includes = ["*.nix"]

rustfmt

command = "rustfmt"
options = ["--edition", "2018"]
includes = ["*.rs"]

rufo

Rufo is an opinionated ruby formatter. By default it exits with status 3 on file change so we have to pass the -x option.

command = "rufo"
options = ["-x"]
includes = ["*.rb"]

cargo fmt

cargo fmt is not supported as it doesn't follow the spec. It doesn't allow to pass arbitrary files to be formatted, which treefmt relies on. Use rustfmt instead (which is what cargo fmt uses under the hood).

shfmt

A shell code formatter.

command = "shfmt"
options = [
  "-i",
  "2",  # indent 2
  "-s",  # simplify the code
  "-w",  # write back to the file
]
includes = ["*.sh"]

terraform

terraform fmt only supports formatting one file at the time. See https://github.com/hashicorp/terraform/pull/28191