Add `Style/RedundantFreeze` to remove redudant `.freeze`

Since Rails 6.0 will support Ruby 2.4.1 or higher
`# frozen_string_literal: true` magic comment is enough to make string object frozen.
This magic comment is enabled by `Style/FrozenStringLiteralComment` cop.

* Exclude these files not to auto correct false positive `Regexp#freeze`
 - 'actionpack/lib/action_dispatch/journey/router/utils.rb'
 - 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb'

It has been fixed by https://github.com/rubocop-hq/rubocop/pull/6333
Once the newer version of RuboCop released and available at Code Climate these exclude entries should be removed.

* Replace `String#freeze` with `String#-@` manually if explicit frozen string objects are required

 - 'actionpack/test/controller/test_case_test.rb'
 - 'activemodel/test/cases/type/string_test.rb'
 - 'activesupport/lib/active_support/core_ext/string/strip.rb'
 - 'activesupport/test/core_ext/string_ext_test.rb'
 - 'railties/test/generators/actions_test.rb'

1 files changed, 4 insertions, 4 deletions

diff --git a/actionview/lib/action_view/helpers/form_options_helper.rb b/actionview/lib/action_view/helpers/form_options_helper.rb
index 2b9d55a019..ebdd96f570 100644
--- a/actionview/lib/action_view/helpers/form_options_helper.rb
+++ b/actionview/lib/action_view/helpers/form_options_helper.rb
@@ -463,7 +463,7 @@ module ActionView
           option_tags = options_from_collection_for_select(
             value_for_collection(group, group_method), option_key_method, option_value_method, selected_key)
 
-          content_tag("optgroup".freeze, option_tags, label: value_for_collection(group, group_label_method))
+          content_tag("optgroup", option_tags, label: value_for_collection(group, group_label_method))
         end.join.html_safe
       end
 
@@ -535,7 +535,7 @@ module ActionView
         body = "".html_safe
 
         if prompt
-          body.safe_concat content_tag("option".freeze, prompt_text(prompt), value: "")
+          body.safe_concat content_tag("option", prompt_text(prompt), value: "")
         end
 
         grouped_options.each do |container|
@@ -548,7 +548,7 @@ module ActionView
           end
 
           html_attributes = { label: label }.merge!(html_attributes)
-          body.safe_concat content_tag("optgroup".freeze, options_for_select(container, selected_key), html_attributes)
+          body.safe_concat content_tag("optgroup", options_for_select(container, selected_key), html_attributes)
         end
 
         body
@@ -584,7 +584,7 @@ module ActionView
           end
 
           zone_options.safe_concat options_for_select(convert_zones[priority_zones], selected)
-          zone_options.safe_concat content_tag("option".freeze, "-------------", value: "", disabled: true)
+          zone_options.safe_concat content_tag("option", "-------------", value: "", disabled: true)
           zone_options.safe_concat "\n"
 
           zones = zones - priority_zones