ensure virtual attribute hashes and methods have consistent types

Now that we are opening up delegation to virtual_has_many, we need to nail down

Author: kbrock

lib/active_record/virtual_attributes.rb

@@ -102,7 +102,7 @@ def load_schema!
       end
 
       def define_virtual_attribute(name, cast_type, uses: nil, arel: nil)
-        attribute_types[name] = cast_type
+        attribute_types[name.to_s] = cast_type
         define_virtual_include(name, uses) if uses
         define_virtual_arel(name, arel) if arel
       end

lib/active_record/virtual_attributes/virtual_arel.rb

@@ -111,7 +111,7 @@ def arel_for_virtual_attribute(column_name, table) # :nodoc:
         private
 
         def define_virtual_arel(name, arel) # :nodoc:
-          self._virtual_arel = _virtual_arel.merge(name => arel)
+          self._virtual_arel = _virtual_arel.merge(name.to_s => arel)
         end
       end
     end

lib/active_record/virtual_attributes/virtual_delegates.rb

@@ -44,7 +44,7 @@ def virtual_delegate(*methods, to:, type: nil, prefix: nil, allow_nil: nil, defa
             define_delegate(method_name, method, :to => to, :allow_nil => allow_nil, :default => default)
 
             self.virtual_delegates_to_define =
-              virtual_delegates_to_define.merge(method_name => [method, options.merge(:to => to, :type => type)])
+              virtual_delegates_to_define.merge(method_name.to_s => [method, options.merge(:to => to, :type => type)])
           end
         end
 

lib/active_record/virtual_attributes/virtual_includes.rb

@@ -25,7 +25,7 @@ def virtual_includes(name)
         private
 
         def define_virtual_include(name, uses)
-          self._virtual_includes = _virtual_includes.merge(name => uses)
+          self._virtual_includes = _virtual_includes.merge(name.to_s => uses)
         end
       end
     end