Driver swapping on RSpec 2

lib/capybara/dsl.rb

@@ -39,6 +39,17 @@ def use_default_driver
       @current_driver = nil
     end
 
+    ##
+    #
+    # Yield a block using a specific driver
+    #
+    def using_driver(driver)
+      Capybara.current_driver = driver
+      yield
+    ensure
+      Capybara.use_default_driver
+    end
+
     ##
     #
     # The current Capybara::Session base on what is set as Capybara.app and Capybara.current_driver

lib/capybara/rspec.rb

@@ -0,0 +1,12 @@
+if defined? RSpec::Core::Example
+  class RSpec::Core::Example
+
+    alias_method :__run_before_swinger, :run
+    private :__run_before_swinger
+
+    def run(*args)
+      Capybara.using_driver(metadata[:driver]) { __run_before_swinger(*args) }
+    end
+
+  end
+end

spec/dsl_spec.rb

@@ -56,6 +56,32 @@
     end
   end
 
+  describe '#using_driver' do
+    before do
+      Capybara.current_driver.should_not == :selenium
+    end
+
+    it 'should set the driver using Capybara.current_driver=' do
+      driver = nil
+      Capybara.using_driver(:selenium) { driver = Capybara.current_driver }
+      driver.should == :selenium
+    end
+
+    it 'should reset the driver using Capybara.use_default_driver, even if an exception occurs' do
+      begin
+        Capybara.using_driver(:selenium) { raise "ohnoes!" }
+      rescue Exception
+      end
+      Capybara.current_driver.should == Capybara.default_driver
+    end
+
+    it 'should yield the passed block' do
+      called = false
+      Capybara.using_driver(:selenium) { called = true }
+      called.should == true
+    end
+  end
+
   describe '#app' do
     it "should be changeable" do
       Capybara.app = "foobar"

spec/rspec_spec.rb

@@ -0,0 +1,21 @@
+require 'spec_helper'
+require 'capybara/dsl'
+require 'capybara/rspec'
+
+describe RSpec::Core::Example do
+
+  before do
+    @group = RSpec::Core::ExampleGroup.describe
+  end
+
+  it 'should call Capybara.using_driver' do
+    Capybara.should_receive(:using_driver).with(:selenium)
+    @group.example("does something", {:driver => :selenium}).run
+  end
+
+  it "does not show the original aliased method" do
+    methods = @group.example("without public aliased method").methods
+    methods.should_not include('__run_before_swinger')
+  end
+
+end