Don't mangle callable enum names

Related rails#39677, rails#39700, rails#40804 (comment).

The intent of rails#39700 is to mangle non-callable enum names to avoid
`public_send`, but `\W` (non-word) character class includes Unicode
characters which are valid for callable method name in Ruby.

It should be limited to mangle enum names only for non-word *ASCII*
characters.

Author: kamipo

activerecord/lib/active_record/enum.rb

@@ -202,7 +202,7 @@ def enum(definitions)
               suffix = "_#{enum_suffix}"
             end
 
-            method_friendly_label = label.to_s.gsub(/\W+/, "_")
+            method_friendly_label = label.to_s.gsub(/[\W&&[:ascii:]]+/, "_")
             value_method_name = "#{prefix}#{method_friendly_label}#{suffix}"
             value_method_names << value_method_name
             enum_values[label] = value

activerecord/test/cases/enum_test.rb

@@ -646,6 +646,17 @@ def self.name; "Book"; end
     assert_not_predicate computer, :extendedGold?
   end
 
+  test "unicode characters for enum names" do
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = "books"
+      enum language: [:🇺🇸, :🇪🇸, :🇫🇷]
+    end
+
+    book = klass.🇺🇸.build
+    assert_predicate book, :🇺🇸?
+    assert_not_predicate book, :🇪🇸?
+  end
+
   test "enum logs a warning if auto-generated negative scopes would clash with other enum names" do
     old_logger = ActiveRecord::Base.logger
     logger = ActiveSupport::LogSubscriber::TestHelper::MockLogger.new