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_tag_helper.rb b/actionview/lib/action_view/helpers/form_tag_helper.rb
index ba09738beb..c0996049f0 100644
--- a/actionview/lib/action_view/helpers/form_tag_helper.rb
+++ b/actionview/lib/action_view/helpers/form_tag_helper.rb
@@ -146,15 +146,15 @@ module ActionView
           end
 
           if include_blank
-            option_tags = content_tag("option".freeze, include_blank, options_for_blank_options_tag).safe_concat(option_tags)
+            option_tags = content_tag("option", include_blank, options_for_blank_options_tag).safe_concat(option_tags)
           end
         end
 
         if prompt = options.delete(:prompt)
-          option_tags = content_tag("option".freeze, prompt, value: "").safe_concat(option_tags)
+          option_tags = content_tag("option", prompt, value: "").safe_concat(option_tags)
         end
 
-        content_tag "select".freeze, option_tags, { "name" => html_name, "id" => sanitize_to_id(name) }.update(options.stringify_keys)
+        content_tag "select", option_tags, { "name" => html_name, "id" => sanitize_to_id(name) }.update(options.stringify_keys)
       end
 
       # Creates a standard text field; use these text fields to input smaller chunks of text like a username
@@ -577,7 +577,7 @@ module ActionView
       #   # => <fieldset class="format"><p><input id="name" name="name" type="text" /></p></fieldset>
       def field_set_tag(legend = nil, options = nil, &block)
         output = tag(:fieldset, options, true)
-        output.safe_concat(content_tag("legend".freeze, legend)) unless legend.blank?
+        output.safe_concat(content_tag("legend", legend)) unless legend.blank?
         output.concat(capture(&block)) if block_given?
         output.safe_concat("</fieldset>")
       end