Add Rakefile

.gitignore

@@ -1,2 +1,3 @@
 vendor/
 .bundle/
+pkg/

Gemfile.lock

@@ -11,6 +11,7 @@ GEM
     parser (3.1.2.0)
       ast (~> 2.4.1)
     rainbow (3.1.1)
+    rake (13.0.6)
     regexp_parser (2.4.0)
     rexml (3.2.5)
     rubocop (1.29.1)
@@ -24,6 +25,8 @@ GEM
       unicode-display_width (>= 1.4.0, < 3.0)
     rubocop-ast (1.18.0)
       parser (>= 3.1.1.0)
+    rubocop-rake (0.6.0)
+      rubocop (~> 1.0)
     ruby-progressbar (1.11.0)
     unicode-display_width (2.1.0)
 
@@ -32,7 +35,9 @@ PLATFORMS
 
 DEPENDENCIES
   format-staged!
+  rake (~> 13.0)
   rubocop (~> 1.29)
+  rubocop-rake (~> 0.6)
 
 BUNDLED WITH
    2.1.4

Rakefile

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+require 'bundler/gem_tasks'
+
+begin
+  Bundler.setup(:default, :development)
+rescue Bundler::BundlerError => e
+  warn e.message
+  warn 'Run `bundle install` to install missing gems'
+  exit e.status_code
+end
+
+require 'rubocop/rake_task'
+
+desc 'Run RuboCop'
+RuboCop::RakeTask.new(:lint)

format-staged.gemspec

@@ -15,9 +15,11 @@ Gem::Specification.new do |s|
   s.executables << 'git-format-staged'
   s.homepage    = 'https://github.com/5sw/format-staged'
   s.license     = 'MIT'
-  s.required_ruby_version = '2.7'
+  s.required_ruby_version = '~> 2.7'
 
+  s.add_development_dependency 'rake', '~> 13.0'
   s.add_development_dependency 'rubocop', '~> 1.29'
+  s.add_development_dependency 'rubocop-rake', '~> 0.6'
 
   s.metadata = {
     'rubygems_mfa_required' => 'true'