Revert "Merge pull request #27528 from kamipo/extract_casted_booleans"

As pointed out by @matthewd this change makes ImmutableString aware
of MysqlString's existence whereas previously MysqlString was only
overriding public API.

cc @kamipo

This reverts commit e632c2fa4cb60072a778ce95c952a0fa95e5b074, reversing
changes made to 334a7dcf107cd3ff1697163d331d289d6d65dcd7.

1 files changed, 4 insertions, 12 deletions

diff --git a/activemodel/lib/active_model/type/immutable_string.rb b/activemodel/lib/active_model/type/immutable_string.rb
index c967d428ac..58268540e5 100644
--- a/activemodel/lib/active_model/type/immutable_string.rb
+++ b/activemodel/lib/active_model/type/immutable_string.rb
@@ -8,8 +8,8 @@ module ActiveModel
       def serialize(value)
         case value
         when ::Numeric, ActiveSupport::Duration then value.to_s
-        when true then casted_true
-        when false then casted_false
+        when true then "t"
+        when false then "f"
         else super
         end
       end
@@ -19,20 +19,12 @@ module ActiveModel
         def cast_value(value)
           result = \
             case value
-            when true then casted_true
-            when false then casted_false
+            when true then "t"
+            when false then "f"
             else value.to_s
             end
           result.freeze
         end
-
-        def casted_true
-          "t".freeze
-        end
-
-        def casted_false
-          "f".freeze
-        end
     end
   end
 end