Gemfile.lock

@@ -2,11 +2,13 @@ PATH
   remote: .
   specs:
     format-staged (0.0.3)
+      colorize
 
 GEM
   remote: http://rubygems.org/
   specs:
     ast (2.4.2)
+    colorize (0.8.1)
     parallel (1.22.1)
     parser (3.1.2.0)
       ast (~> 2.4.1)

bin/git-format-staged

@@ -57,6 +57,10 @@ parser = OptionParser.new do |opt|
     puts FormatStaged::VERSION
     exit
   end
+  
+  opt.on('--[no-]color', 'Colorizes output') do |value|
+    parameters[:color_output] = value
+  end
 end
 
 parser.parse!

format-staged.gemspec

@@ -16,6 +16,8 @@ Gem::Specification.new do |s|
   s.homepage    = 'https://github.com/5sw/format-staged'
   s.license     = 'MIT'
   s.required_ruby_version = '~> 2.7'
+  
+  s.add_dependency 'colorize'
 
   s.add_development_dependency 'rake', '~> 13.0'
   s.add_development_dependency 'rubocop', '~> 1.29'

lib/format-staged/io.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'English'
+
 class FormatStaged
   def get_output(*args, lines: true, silent: false)
     puts "> #{args.join(' ')}" if @verbose

lib/format_staged.rb

@@ -5,18 +5,21 @@ require 'format-staged/version'
 require 'format-staged/entry'
 require 'format-staged/io'
 require 'shellwords'
+require 'colorize'
 
 ##
 # Runs staged changes through a formatting tool
 class FormatStaged
   attr_reader :formatter, :patterns, :update, :write, :verbose
 
-  def initialize(formatter:, patterns:, update: true, write: true, verbose: true)
+  def initialize(formatter:, patterns:, update: true, write: true, verbose: true, color_output: nil)
     @formatter = formatter
     @patterns = patterns
     @update = update
     @write = write
     @verbose = verbose
+
+    String.disable_colorization = !(color_output || STDOUT.isatty)
   end
 
   def run