Update git init when generating plugins

* Extract separate test, test with `--skip-git`
* Move `version_control` beneath `gitignore` to match `AppBuilder` from 8989a50
* Add changelog entry

Author: kaspth

railties/CHANGELOG.md

@@ -1,3 +1,9 @@
+*   Run `git init` when generating plugins.
+
+    Opt out with `--skip-git`.
+
+    *OKURA Masafumi*
+
 *   Add benchmark generator
 
     Introduce benchmark generator to benchmark Rails applications.

railties/lib/rails/generators/rails/plugin/plugin_generator.rb

@@ -57,6 +57,12 @@ def gitignore
       template "gitignore", ".gitignore"
     end
 
+    def version_control
+      if !options[:skip_git] && !options[:pretend]
+        run "git init", capture: options[:quiet], abort_on_failure: false
+      end
+    end
+
     def lib
       template "lib/%namespaced_name%.rb"
       template "lib/tasks/%namespaced_name%_tasks.rake"
@@ -161,12 +167,6 @@ def gemfile_entry
         append_file gemfile_in_app_path, entry
       end
     end
-
-    def version_control
-      if  !options[:skip_git] && !options[:pretend]
-        run "git init", capture: options[:quiet], abort_on_failure: false
-      end
-    end
   end
 
   module Generators

railties/test/generators/plugin_generator_test.rb

@@ -64,7 +64,7 @@ def test_correct_file_in_lib_folder_of_camelcase_plugin_name
   end
 
   def test_generating_without_options
-    output = run_generator
+    run_generator
     assert_file "README.md", /Bukkits/
     assert_no_file "config/routes.rb"
     assert_no_file "app/assets/config/bukkits_manifest.js"
@@ -79,7 +79,11 @@ def test_generating_without_options
     assert_file "test/bukkits_test.rb", /assert_kind_of Module, Bukkits/
     assert_file "bin/test"
     assert_no_file "bin/rails"
-    assert_match(/run  git init/, output)
+  end
+
+  def test_initializes_git_repo
+    run_generator
+    assert_directory ".git"
   end
 
   def test_generating_in_full_mode_with_almost_of_all_skip_options
@@ -607,6 +611,7 @@ def test_no_details_from_git_when_skip_git
       assert_match name, contents
       assert_match email, contents
     end
+    assert_no_directory ".git"
   end
 
   def test_skipping_useless_folders_generation_for_api_engines