Merge #6455

6455: [CLI::Gem] Add a --rubocop option r=deivid-rodriguez a=segiddins

Based upon #6451.

### What was the end-user problem that led to this PR?

The problem was I always have to remember how to add RuboCop to my Rakefile when I set up a new gem.

### What was your diagnosis of the problem?

My diagnosis was that RuboCop has become enough of a community standard that it makes sense to offer it in `bundle gem`.

### What is your fix for the problem, implemented in this PR?

My fix adds an option to `bundle gem` to add in RuboCop, in the same way options like `:coc`and `:mit` are handled.

### Why did you choose this fix out of the possible options?

I chose this fix because it does not require bundler have an opinion on _how_ rubocop is configured.

Co-authored-by: Samuel Giddins <segiddins@segiddins.me>

2 files changed, 13 insertions, 3 deletions

diff --git a/lib/bundler/templates/newgem/Gemfile.tt b/lib/bundler/templates/newgem/Gemfile.tt
index 83878ec7f8..7b0296068b 100644
--- a/lib/bundler/templates/newgem/Gemfile.tt
+++ b/lib/bundler/templates/newgem/Gemfile.tt
@@ -10,3 +10,6 @@ gem "rake-compiler"
 <%- if config[:test] -%>
 gem "<%= config[:test] %>", "~> <%= config[:test_framework_version] %>"
 <%- end -%>
+<%- if config[:rubocop] -%>
+gem "rubocop"
+<%- end -%>
diff --git a/lib/bundler/templates/newgem/Rakefile.tt b/lib/bundler/templates/newgem/Rakefile.tt
index 099da6f3ec..1262457c72 100644
--- a/lib/bundler/templates/newgem/Rakefile.tt
+++ b/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"
 
@@ -14,7 +15,15 @@ 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 %>