added checked? to CheckboxField

lib/webrat/core/field.rb

@@ -208,6 +208,10 @@ module Webrat
       set(@element["value"] || "on")
     end
     
+    def checked?
+      @element["checked"] == "checked"
+    end
+
     def uncheck
       raise_error_if_disabled
       set(nil)

spec/core/field_spec.rb

@@ -0,0 +1,15 @@
+require File.expand_path(File.dirname(__FILE__) + "/../spec_helper")
+
+module Webrat
+  describe CheckboxField do
+    it "should say it is checked if it is" do
+      checkbox = CheckboxField.new(nil, (Hpricot("<input type='checkbox' checked='checked'>")/'input').first)
+      checkbox.should be_checked
+    end
+
+    it "should say it is not checked if it is not" do
+      checkbox = CheckboxField.new(nil, (Hpricot("<input type='checkbox'>")/'input').first)
+      checkbox.should_not be_checked
+    end
+  end
+end