Added separate execute_script method, closes #71

README.rdoc

@@ -228,7 +228,12 @@ You can also find specific elements, in order to manipulate them:
 
 === Scripting
 
-In drivers which support it, you can easily evaluate JavaScript:
+In drivers which support it, you can easily execute JavaScript:
+
+    page.execute_script("$('body').empty()")
+
+For simple expressions, you can return the result of the script. Note
+that this may break with more complicated expressions:
 
     result = page.evaluate_script('4 + 4');
 

lib/capybara/driver/base.rb

@@ -11,6 +11,10 @@ class Capybara::Driver::Base
     raise NotImplementedError
   end
 
+  def execute_script(script)
+    raise Capybara::NotSupportedByDriverError
+  end
+
   def evaluate_script(script)
     raise Capybara::NotSupportedByDriverError
   end

lib/capybara/driver/celerity_driver.rb

@@ -125,6 +125,11 @@ class Capybara::Driver::Celerity < Capybara::Driver::Base
 
   def wait?; true; end
 
+  def execute_script(script)
+    browser.execute_script script
+    nil
+  end
+
   def evaluate_script(script)
     browser.execute_script "#{script}"
   end

lib/capybara/driver/selenium_driver.rb

@@ -128,6 +128,10 @@ class Capybara::Driver::Selenium < Capybara::Driver::Base
 
   def wait?; true; end
 
+  def execute_script(script)
+    browser.execute_script script
+  end
+
   def evaluate_script(script)
     browser.execute_script "return #{script}"
   end

lib/capybara/session.rb

@@ -236,6 +236,10 @@ module Capybara
       WaitUntil.timeout(timeout,driver) { yield }
     end
 
+    def execute_script(script)
+      driver.execute_script(script)
+    end
+
     def evaluate_script(script)
       driver.evaluate_script(script)
     end

lib/capybara/spec/session/javascript.rb

@@ -35,12 +35,20 @@ shared_examples_for "session with javascript support" do
     end
 
     describe "#evaluate_script" do
-      it "should return the evaluated script" do
+      it "should evaluate the given script and return whatever it produces" do
         @session.visit('/with_js')
         @session.evaluate_script("1+3").should == 4
       end
     end
 
+    describe "#execute_script" do
+      it "should execute the given script and return nothing" do
+        @session.visit('/with_js')
+        @session.execute_script("$('#change').text('Funky Doodle')").should be_nil
+        @session.should have_css('#change', :text => 'Funky Doodle')
+      end
+    end
+
     describe '#locate' do
       it "should wait for asynchronous load" do
         @session.visit('/with_js')