Fixed that Module#alias_method_chain should work with both foo? foo! and foo...

Fixed that Module#alias_method_chain should work with both foo? foo! and foo at the same time (closes #4954) [anna@wota.jp]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4429 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activesupport/CHANGELOG

 *SVN*
 
+* Fixed that Module#alias_method_chain should work with both foo? foo! and foo at the same time #4954 [anna@wota.jp]
+
 * to_xml fixes, features, and speedup: introduce :dasherize option that converts updated_at to updated-at if true (the existing default); binary columns get encoding="base64" attribute; nil values get nil="true" attribute to distinguish empty values; add type information for float columns; allow arbitrarily deep :include; include SQL type information as the type attribute.  #4989 [Blair Zajac <blair@orcaware.com>]
 
 * Add OrderedHash#values. [Sam Stephenson]

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

@@ -9,11 +9,17 @@ class Module
   #   alias_method_chain :foo, :feature
   #
   # And both aliases are set up for you.
+  #
+  # A punctuation is moved to the end on predicates or bang methods.
+  #
+  #   alias_method_chain :foo?, :feature
+  # 
+  # generates "foo_without_feature?" method for old one,
+  # and expects "foo_with_feature?" method for new one.
   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.
+    punctuation    = target.to_s.scan(/[?!]/).first
     aliased_target = target.to_s.sub(/[?!]/, '')
-    alias_method "#{aliased_target}_without_#{feature}", target
-    alias_method target, "#{aliased_target}_with_#{feature}"
+    alias_method "#{aliased_target}_without_#{feature}#{punctuation}", target
+    alias_method target, "#{aliased_target}_with_#{feature}#{punctuation}"
   end
 end

activesupport/test/core_ext/module_test.rb

@@ -109,8 +109,12 @@ def bar_with_baz
     bar_without_baz << '_with_baz'
   end
 
-  def quux_with_baz
-    quux_without_baz << '_with_baz'
+  def quux_with_baz!
+    quux_without_baz! << '_with_baz!'
+  end
+
+  def quux_with_baz?
+    false
   end
 end
 
@@ -148,12 +152,30 @@ def test_alias_method_chain
 
   def test_alias_method_chain_with_punctuation_method
     FooClassWithBarMethod.send(:define_method, 'quux!', Proc.new { 'quux' })
-    assert !@instance.respond_to?(:quux_with_baz)
+    assert !@instance.respond_to?(:quux_with_baz!)
     FooClassWithBarMethod.send(:include, BarMethodAliaser)
     FooClassWithBarMethod.alias_method_chain :quux!, :baz
-    assert @instance.respond_to?(:quux_with_baz)
+    assert @instance.respond_to?(:quux_with_baz!)
+    
+    assert_equal 'quux_with_baz!', @instance.quux!
+    assert_equal 'quux', @instance.quux_without_baz!
+  end
 
-    assert_equal 'quux_with_baz', @instance.quux!
-    assert_equal 'quux', @instance.quux_without_baz
+  def test_alias_method_chain_with_same_names_between_predicates_and_bang_methods
+    FooClassWithBarMethod.send(:define_method, 'quux!', Proc.new { 'quux' })
+    FooClassWithBarMethod.send(:define_method, 'quux?', Proc.new { true })
+    assert !@instance.respond_to?(:quux_with_baz!)
+    assert !@instance.respond_to?(:quux_with_baz?)
+  
+    FooClassWithBarMethod.send(:include, BarMethodAliaser)
+    FooClassWithBarMethod.alias_method_chain :quux!, :baz
+    FooClassWithBarMethod.alias_method_chain :quux?, :baz
+  
+    assert @instance.respond_to?(:quux_with_baz!)
+    assert @instance.respond_to?(:quux_with_baz?)
+    assert_equal 'quux_with_baz!', @instance.quux!
+    assert_equal 'quux', @instance.quux_without_baz!
+    assert_equal false, @instance.quux?
+    assert_equal true,  @instance.quux_without_baz?
   end
 end