alias_method_chain preserves method punctuation so foo, foo?, and foo! may be chained with the same feature.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4482 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 14 insertions, 3 deletions

diff --git a/activesupport/lib/active_support/core_ext/module/aliasing.rb b/activesupport/lib/active_support/core_ext/module/aliasing.rb
index 1f904377df..167bc75057 100644
--- a/activesupport/lib/active_support/core_ext/module/aliasing.rb
+++ b/activesupport/lib/active_support/core_ext/module/aliasing.rb
@@ -9,11 +9,22 @@ class Module
   #   alias_method_chain :foo, :feature
   #
   # And both aliases are set up for you.
+  #
+  # Query and bang methods (foo?, foo!) keep the same punctuation:
+  #
+  #   alias_method_chain :foo?, :feature
+  #
+  # is equivalent to
+  #
+  #   alias_method :foo_without_feature?, :foo?
+  #   alias_method :foo?, :foo_without_feature?
+  #
+  # so you can safely chain foo, foo?, and foo! with the same feature.
   def alias_method_chain(target, feature)
     # Strip out punctuation on predicates or bang methods since
     # e.g. target?_without_feature is not a valid method name.
-    aliased_target = target.to_s.sub(/[?!]/, '')
-    alias_method "#{aliased_target}_without_#{feature}", target
-    alias_method target, "#{aliased_target}_with_#{feature}"
+    aliased_target, punctuation = target.to_s.sub(/([?!])$/, ''), $1
+    alias_method "#{aliased_target}_without_#{feature}#{punctuation}", target
+    alias_method target, "#{aliased_target}_with_#{feature}#{punctuation}"
   end
 end