[CLI::Gem] Add a --rubocop option

lib/bundler/cli.rb

@@ -515,6 +515,7 @@ def viz
                          :desc => "Open generated gemspec in the specified editor (defaults to $EDITOR or $BUNDLER_EDITOR)"
     method_option :ext, :type => :boolean, :default => false, :desc => "Generate the boilerplate for C extension code"
     method_option :mit, :type => :boolean, :desc => "Generate an MIT license file. Set a default with `bundle config gem.mit true`."
+    method_option :rubocop, :type => :boolean, :desc => "Add rubocop to the generated Rakefile and gemspec"
     method_option :test, :type => :string, :lazy_default => "rspec", :aliases => "-t", :banner => "rspec",
                          :desc => "Generate a test directory for your library, either rspec or minitest. Set a default with `bundle config gem.test rspec`."
     def gem(name)

lib/bundler/cli/gem.rb

@@ -101,7 +101,7 @@ def run
         end
       end
 
-      config[:test_task] = config[:test] == "minitest" ? "test" : "spec"
+      config[:test_task] = config[:test] == "minitest" ? :test : :spec
 
       if ask_and_set(:mit, "Do you want to license your code permissively under the MIT license?",
         "This means that any other developer or company will be legally allowed to use your code " \
@@ -125,6 +125,15 @@ def run
         templates.merge!("CODE_OF_CONDUCT.md.tt" => "CODE_OF_CONDUCT.md")
       end
 
+      if ask_and_set(:rubocop, "Do you want to add rubocop as a dependency for gems you generate?",
+        "RuboCop is a static code analyzer that has out-of-the-box rules for many" \
+        "of the guidelines in the community style guide." \
+        "For more information, see the RuboCop docs (https://rubocop.readthedocs.io/en/latest/)" \
+        "and the Ruby Style Guides (https://github.com/bbatsov/ruby-style-guide).")
+        config[:rubocop] = true
+        Bundler.ui.info "RuboCop enabled in config"
+      end
+
       templates.merge!("exe/newgem.tt" => "exe/#{name}") if config[:exe]
 
       if options[:ext]

lib/bundler/templates/newgem/Rakefile.tt

@@ -1,4 +1,5 @@
 require "bundler/gem_tasks"
+<% default_task_names = [config[:test_task]] -%>
 <% if config[:test] == "minitest" -%>
 require "rake/testtask"
 
@@ -13,8 +14,16 @@ require "rspec/core/rake_task"
 
 RSpec::Core::RakeTask.new(:spec)
 
+<% end -%>
+<% if config[:rubocop] -%>
+<% default_task_names << :rubocop -%>
+require "rubocop/rake_task"
+
+RuboCop::RakeTask.new
+
 <% end -%>
 <% if config[:ext] -%>
+<% default_task_names.unshift(:clobber, :compile) -%>
 require "rake/extensiontask"
 
 task :build => :compile
@@ -23,7 +32,5 @@ Rake::ExtensionTask.new("<%= config[:underscored_name] %>") do |ext|
   ext.lib_dir = "lib/<%= config[:namespaced_path] %>"
 end
 
-task :default => [:clobber, :compile, :<%= config[:test_task] %>]
-<% else -%>
-task :default => :<%= config[:test_task] %>
 <% end -%>
+task :default => <%= default_task_names.size == 1 ? default_task_names.first.inspect : default_task_names.inspect %>

lib/bundler/templates/newgem/newgem.gemspec.tt

@@ -45,4 +45,7 @@ Gem::Specification.new do |spec|
 <%- if config[:test] -%>
   spec.add_development_dependency "<%= config[:test] %>", "~> <%= config[:test_framework_version] %>"
 <%- end -%>
+<%- if config[:rubocop] -%>
+  spec.add_development_dependency "rubocop"
+<%- end -%>
 end

spec/commands/newgem_spec.rb

@@ -3,7 +3,7 @@
 RSpec.describe "bundle gem" do
   def reset!
     super
-    global_config "BUNDLE_GEM__MIT" => "false", "BUNDLE_GEM__TEST" => "false", "BUNDLE_GEM__COC" => "false"
+    global_config "BUNDLE_GEM__MIT" => "false", "BUNDLE_GEM__TEST" => "false", "BUNDLE_GEM__COC" => "false", "BUNDLE_GEM__RUBOCOP" => "false"
   end
 
   def remove_push_guard(gem_name)
@@ -128,6 +128,36 @@ def gem_skeleton_assertions(gem_name)
     end
   end
 
+  shared_examples_for "--rubocop flag" do
+    before do
+      execute_bundle_gem(gem_name, "--rubocop", false)
+    end
+
+    it "generates a gem skeleton with rubocop" do
+      gem_skeleton_assertions(gem_name)
+      expect(bundled_app("test-gem/Rakefile")).to read_as(
+        include('require "rubocop/rake_task"').
+        and(include("RuboCop::RakeTask.new").
+        and(match(/:default.+:rubocop/)))
+      )
+      expect(bundled_app("test-gem/#{gem_name}.gemspec")).to read_as(include('spec.add_development_dependency "rubocop"'))
+    end
+  end
+
+  shared_examples_for "--no-rubocop flag" do
+    define_negated_matcher :exclude, :include
+
+    before do
+      execute_bundle_gem(gem_name, "--no-rubocop", false)
+    end
+
+    it "generates a gem skeleton without rubocop" do
+      gem_skeleton_assertions(gem_name)
+      expect(bundled_app("test-gem/Rakefile")).to read_as(exclude("rubocop"))
+      expect(bundled_app("test-gem/#{gem_name}.gemspec")).to read_as(exclude("rubocop"))
+    end
+  end
+
   context "README.md" do
     let(:gem_name) { "test_gem" }
     let(:generated_gem) { Bundler::GemHelper.new(bundled_app(gem_name).to_s) }
@@ -532,7 +562,7 @@ module TestGem
 
     context "with mit option in bundle config settings set to true" do
       before do
-        global_config "BUNDLE_GEM__MIT" => "true", "BUNDLE_GEM__TEST" => "false", "BUNDLE_GEM__COC" => "false"
+        global_config "BUNDLE_GEM__MIT" => "true", "BUNDLE_GEM__TEST" => "false", "BUNDLE_GEM__RUBOCOP" => "false", "BUNDLE_GEM__COC" => "false"
       end
       after { reset! }
       it_behaves_like "--mit flag"
@@ -546,7 +576,7 @@ module TestGem
 
     context "with coc option in bundle config settings set to true" do
       before do
-        global_config "BUNDLE_GEM__MIT" => "false", "BUNDLE_GEM__TEST" => "false", "BUNDLE_GEM__COC" => "true"
+        global_config "BUNDLE_GEM__MIT" => "false", "BUNDLE_GEM__TEST" => "false", "BUNDLE_GEM__RUBOCOP" => "false", "BUNDLE_GEM__COC" => "true"
       end
       after { reset! }
       it_behaves_like "--coc flag"
@@ -557,6 +587,20 @@ module TestGem
       it_behaves_like "--coc flag"
       it_behaves_like "--no-coc flag"
     end
+
+    context "with rubocop option in bundle config settings set to true" do
+      before do
+        global_config "BUNDLE_GEM__MIT" => "false", "BUNDLE_GEM__TEST" => "false", "BUNDLE_GEM__COC" => "false", "BUNDLE_GEM__RUBOCOP" => "true"
+      end
+      after { reset! }
+      it_behaves_like "--rubocop flag"
+      it_behaves_like "--no-rubocop flag"
+    end
+
+    context "with rubocop option in bundle config settings set to false" do
+      it_behaves_like "--rubocop flag"
+      it_behaves_like "--no-rubocop flag"
+    end
   end
 
   context "gem naming with dashed" do