removed whitespace and added dsl shortcut to evaluate_script method

lib/capybara.rb

@@ -6,6 +6,7 @@ module Capybara
   class CapybaraError < StandardError; end
   class DriverNotFoundError < CapybaraError; end
   class ElementNotFound < CapybaraError; end
+  class NotSupportedByDriverError < CapybaraError; end
 
   class << self
     attr_accessor :debug, :asset_root

lib/capybara/dsl.rb

@@ -50,7 +50,7 @@ module Capybara
     :visit, :body, :click_link, :click_button, :fill_in, :choose, :has_xpath?, :has_css?,
     :check, :uncheck, :attach_file, :select, :has_content?, :within, :within_fieldset,
     :within_table, :save_and_open_page, :find, :find_field, :find_link, :find_button,
-    :field_labeled, :all
+    :field_labeled, :all, :evaluate_script
   ]
   SESSION_METHODS.each do |method|
     class_eval <<-RUBY, __FILE__, __LINE__+1

lib/capybara/session.rb

@@ -158,6 +158,14 @@ module Capybara
       button || find("//button[@id='#{locator}' or @value='#{locator}' or contains(.,'#{locator}')]")
     end
 
+    def evaluate_script(script)
+      begin
+        driver.evaluate_script(script)
+      rescue NoMethodError
+        raise NotSupportedByDriverError
+      end
+    end
+
   private
 
     def css_to_xpath(css)

spec/dsl_spec.rb

@@ -114,6 +114,7 @@ describe Capybara do
     end
 
     it_should_behave_like "session"
+    it_should_behave_like "session without javascript driver"
 
     it "should be possible to include it in another class" do
       klass = Class.new do

spec/session/culerity_session_spec.rb

@@ -19,5 +19,6 @@ describe Capybara::Session do
     end
 
     it_should_behave_like "session"
+    it_should_behave_like "session with javascript driver"
   end
 end

spec/session/rack_test_session_spec.rb

@@ -19,5 +19,6 @@ describe Capybara::Session do
     end
 
     it_should_behave_like "session"
+    it_should_behave_like "session without javascript driver"
   end
 end

spec/session/selenium_session_spec.rb

@@ -19,5 +19,6 @@ describe Capybara::Session do
     end
 
     it_should_behave_like "session"
+    it_should_behave_like "session with javascript driver"
   end
 end

spec/session_spec.rb

@@ -793,6 +793,28 @@ shared_examples_for "session" do
       extract_results(@session)['villain_name'].should == 'Quantum'
     end
   end
+
+end
+
+shared_examples_for "session with javascript driver" do
+  describe "#evaluate_script" do
+    before{ @session.visit('/with_js') }
+    it "should return the evaluated script" do
+      @session.evaluate_script("1+3").should == 4
+    end
+  end
+end
+
+
+shared_examples_for "session without javascript driver" do
+  describe "#evaluate_script" do
+    before{ @session.visit('/with_js') }
+    it "should raise an error" do
+      running {
+        @session.evaluate_script("1+5")
+      }.should raise_error(Capybara::NotSupportedByDriverError)
+    end
+  end
 end
 
 describe Capybara::Session do
@@ -804,3 +826,4 @@ describe Capybara::Session do
     end
   end
 end
+