test both ERB and Erubis

test/erb_test.rb

@@ -1,6 +1,15 @@
 require File.dirname(__FILE__) + '/helper'
 
 class ERBTest < Test::Unit::TestCase
+  def engine
+    Tilt::ERBTemplate
+  end
+
+  def setup
+    Tilt.prefer engine, :erb
+    super
+  end
+
   def erb_app(&block)
     mock_app {
       set :views, File.dirname(__FILE__) + '/views'
@@ -9,6 +18,10 @@ class ERBTest < Test::Unit::TestCase
     get '/'
   end
 
+  it 'uses the correct engine' do
+    assert_equal engine, Tilt[:erb]
+  end
+
   it 'renders inline ERB strings' do
     erb_app { erb '<%= 1 + 1 %>' }
     assert ok?
@@ -79,3 +92,13 @@ class ERBTest < Test::Unit::TestCase
     assert_equal '<outer><inner>hi</inner></outer>', body
   end
 end
+
+
+begin
+  require 'erubis'
+  class ErubisTest < ERBTest
+    def engine; Tilt::ErubisTemplate end
+  end
+rescue LoadError
+  warn "#{$!.to_s}: skipping erubis tests"
+end