rubocop added

.rubocop.yml

@@ -0,0 +1,15 @@
+AllCops:
+  Exclude:
+    - 'bin/**/*'
+
+Style/CommentedKeyword:
+  Enabled: false
+
+Style/Documentation:
+  Enabled: false
+
+Style/Semicolon:
+  Enabled: false
+
+Metrics/LineLength:
+  Max: 170

Gemfile

@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 source 'https://rubygems.org'
 
-git_source(:github) { |repo_name| 'https://github.com/#{repo_name}' }
+git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 # Specify your gem's dependencies in typerb.gemspec
 gemspec

Gemfile.lock

@@ -1,18 +1,25 @@
 PATH
   remote: .
   specs:
-    typerb (0.1.2)
+    typerb (0.1.3)
 
 GEM
   remote: https://rubygems.org/
   specs:
+    ast (2.4.0)
     awesome_print (1.8.0)
     coderay (1.1.2)
     diff-lcs (1.3)
+    jaro_winkler (1.5.1)
     method_source (0.9.1)
+    parallel (1.12.1)
+    parser (2.5.3.0)
+      ast (~> 2.4.0)
+    powerpack (0.1.2)
     pry (0.12.0)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
+    rainbow (3.0.0)
     rake (10.5.0)
     rspec (3.8.0)
       rspec-core (~> 3.8.0)
@@ -27,8 +34,18 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.8.0)
     rspec-support (3.8.0)
+    rubocop (0.60.0)
+      jaro_winkler (~> 1.5.1)
+      parallel (~> 1.10)
+      parser (>= 2.5, != 2.5.1.1)
+      powerpack (~> 0.1)
+      rainbow (>= 2.2.2, < 4.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.4.0)
+    ruby-progressbar (1.10.0)
     super_awesome_print (0.2.5)
       awesome_print
+    unicode-display_width (1.4.0)
 
 PLATFORMS
   ruby
@@ -38,6 +55,7 @@ DEPENDENCIES
   pry
   rake (>= 10.0)
   rspec (>= 3.0)
+  rubocop
   super_awesome_print
   typerb!
 

Rakefile

@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
 
 RSpec::Core::RakeTask.new(:spec)
 
-task :default => :spec
+task default: :spec

lib/typerb.rb

@@ -4,14 +4,14 @@
 
 module Typerb
   refine Object do
-    def type!(*klasses)
+    def type!(*klasses) # rubocop: disable Metrics/CyclomaticComplexity, Metrics/AbcSize, Metrics/MethodLength NOTE: temporary
       raise ArgumentError, 'provide at least one class' if klasses.empty?
       return if klasses.any? { |kls| is_a?(kls) }
 
       kls_text = klasses.size > 1 ? klasses.map(&:name).join(' or ') : klasses.first.name
 
       # error message when multiple calls on the same line, or in a console - can't extract variable name
-      exception_text = "expected #{kls_text}, got #{self.class} (#{to_s})"
+      exception_text = "expected #{kls_text}, got #{self.class} (#{self})"
 
       where = caller_locations(1, 1)[0]
       file = where.path
@@ -21,7 +21,7 @@ def type!(*klasses)
         node = RubyVM::AST.parse(code)
         if node.children.last.children.size == 3 && node.children.last.children[1] == :type!
           var_name = node.children.last.children.first.children.first
-          exception_text = "`#{var_name}` should be #{kls_text}, not #{self.class} (#{to_s})"
+          exception_text = "`#{var_name}` should be #{kls_text}, not #{self.class} (#{self})"
         end
       end
       exception = TypeError.new(exception_text)

spec/typerb_spec.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-RSpec.describe Typerb do
+RSpec.describe Typerb do # rubocop: disable Metrics/BlockLength
   it 'has a version number' do
     expect(Typerb::VERSION).not_to be nil
   end
@@ -35,15 +35,15 @@ def initialize(arg1, arg2, arg3)
     expect { kls.new('hello', 1, {}) }.to raise_error(TypeError, '`arg1` should be Numeric, not String (hello)')
     expect { kls.new(1, 123, {}) }.to raise_error(TypeError, '`arg2` should be String, not Integer (123)')
     expect { kls.new(1, '123', nil) }.to raise_error(TypeError, '`arg3` should be Hash, not NilClass ()')
-    expect { kls.new(123, 'hello', { o: 1 }) }.not_to raise_error
+    expect { kls.new(123, 'hello', o: 1) }.not_to raise_error
   end
 
   it 'raises TypeError for wrong type and ugly syntax' do
     kls = Class.new do
       using Typerb
 
       def initialize(arg)
-        arg.                type!(Integer)
+        arg.                type!(Integer) # rubocop: disable Layout/ExtraSpacing
         # NOTE cannot split into multiline, i.e. this will not work
         # arg.
         #    type!(Integer)
@@ -65,7 +65,7 @@ def initialize(arg)
     end
     expect { kls.new(123) }.not_to raise_error
     expect { kls.new('123') }.not_to raise_error
-    expect { kls.new({hello: 123}) }.to raise_error(TypeError, '`arg` should be Integer or String, not Hash ({:hello=>123})')
+    expect { kls.new(hello: 123) }.to raise_error(TypeError, '`arg` should be Integer or String, not Hash ({:hello=>123})')
   end
 
   it '(kind of) works with multiple args on the same line 1', multiline: true do

typerb.gemspec

@@ -1,4 +1,6 @@
-lib = File.expand_path('../lib', __FILE__)
+# frozen_string_literal: true
+
+lib = File.expand_path('lib', __dir__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'typerb/version'
 
@@ -8,8 +10,8 @@ Gem::Specification.new do |spec|
   spec.authors       = ['Oleg Antonyan']
   spec.email         = ['[email protected]']
 
-  spec.summary       = %q(Typecheck sugar for Ruby.)
-  spec.description   = %q(Typecheck sugar for Ruby.)
+  spec.summary       = 'Typecheck sugar for Ruby.'
+  spec.description   = 'Typecheck sugar for Ruby.'
   spec.homepage      = 'https://github.com/olegantonyan/typerb'
   spec.license       = 'MIT'
 
@@ -23,10 +25,11 @@ Gem::Specification.new do |spec|
   spec.require_paths = ['lib']
 
   spec.add_development_dependency 'bundler', '>= 1.17'
+  spec.add_development_dependency 'pry'
   spec.add_development_dependency 'rake', '>= 10.0'
   spec.add_development_dependency 'rspec', '>= 3.0'
+  spec.add_development_dependency 'rubocop'
   spec.add_development_dependency 'super_awesome_print'
-  spec.add_development_dependency 'pry'
 
   spec.required_ruby_version = '>= 2.6.0-preview3'
 end