Array#wrap should use #to_ary so association collections and named scopes are not re-wrapped

[#1935 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activesupport/lib/active_support/core_ext/array/wrapper.rb

@@ -2,7 +2,8 @@ module ActiveSupport #:nodoc:
   module CoreExtensions #:nodoc:
     module Array #:nodoc:
       module Wrapper
-        # Wraps the object in an Array unless it's an Array.
+        # Wraps the object in an Array unless it's an Array.  Converts the
+        # object to an Array using #to_ary if it implements that.
         def wrap(object)
           case object
           when nil
@@ -10,7 +11,11 @@ module ActiveSupport #:nodoc:
           when self
             object
           else
-            [object]
+            if object.respond_to?(:to_ary)
+              object.to_ary
+            else
+              [object]
+            end
           end
         end
       end

activesupport/test/core_ext/array_ext_test.rb

@@ -304,6 +304,12 @@ class ArrayExtRandomTests < Test::Unit::TestCase
 end
 
 class ArrayWrapperTests < Test::Unit::TestCase
+  class FakeCollection
+    def to_ary
+      ["foo", "bar"]
+    end
+  end
+
   def test_array
     ary = %w(foo bar)
     assert_same ary, Array.wrap(ary)
@@ -325,4 +331,8 @@ class ArrayWrapperTests < Test::Unit::TestCase
   def test_string_with_newline
     assert_equal ["foo\nbar"], Array.wrap("foo\nbar")
   end
+
+  def test_object_with_to_ary
+    assert_equal ["foo", "bar"], Array.wrap(FakeCollection.new)
+  end
 end