Merge pull request rails#50698 from byroot/delegate-reduce-fstring

`Module#delegate` avoid creating a unique fstring for each delegator

Author: byroot

activesupport/lib/active_support/core_ext/module/delegation.rb

@@ -5,7 +5,13 @@
 class Module
   # Error generated by +delegate+ when a method is called on +nil+ and +allow_nil+
   # option is not used.
-  class DelegationError < NoMethodError; end
+  class DelegationError < NoMethodError
+    class << self
+      def nil_target(method_name, target) # :nodoc:
+        new("#{method_name} delegated to #{target}, but #{target} is nil")
+      end
+    end
+  end
 
   RUBY_RESERVED_KEYWORDS = %w(__ENCODING__ __LINE__ __FILE__ alias and BEGIN begin break
   case class def defined? do else elsif END end ensure false for if in module next nil
@@ -266,7 +272,7 @@ def delegate(*methods, to: nil, prefix: nil, allow_nil: nil, private: nil, as: n
           "  _.#{method}(#{definition})" <<
           "rescue NoMethodError => e" <<
           "  if _.nil? && e.name == :#{method}" <<
-          %(   raise DelegationError, "#{self}##{method_name} delegated to #{receiver}.#{method}, but #{receiver} is nil: \#{self.inspect}") <<
+          "    raise DelegationError.nil_target(:#{method_name}, :'#{receiver}')" <<
           "  else" <<
           "    raise" <<
           "  end" <<
@@ -347,7 +353,7 @@ def method_missing(method, ...)
               if #{allow_nil == true}
                 nil
               else
-                raise DelegationError, "\#{method} delegated to #{target}, but #{target} is nil"
+                raise DelegationError.nil_target(method, :'#{target}')
               end
             else
               raise