Allow a minimum IE version to be specified

README.markdown

@@ -24,6 +24,10 @@ or let the default kick in
 
     use Rack::NoIE6
 
+You can even specify a minimum version of IE like so
+
+use Rack::NoIE6, :redirect => 'http://slashdot.org', :minimum => 6.0
+
 # Rails usage
 
 inside environment.rb's Rails::Initializer.run

lib/noie6.rb

@@ -4,6 +4,7 @@ def initialize(app, options = {})
       @app = app
       @options = options
       @options[:redirect] ||= 'http://www.microsoft.com/windows/internet-explorer/default.aspx'
+      @options[:minimum] ||= 7.0
     end
 
     def call(env)
@@ -13,9 +14,18 @@ def call(env)
     private
     def ie6_found_in?(env)
       if env['HTTP_USER_AGENT']
-        env['HTTP_USER_AGENT'][/MSIE 6.0/] and @options[:redirect] != env['PATH_INFO']
+        is_ie?(env['HTTP_USER_AGENT']) and ie_version(env['HTTP_USER_AGENT']) < @options[:minimum] and @options[:redirect] != env['PATH_INFO']
       end
     end
+
+    def is_ie?(ua_string)
+      # We need at least one digit to be able to get the version, hence the \d
+      ua_string.match(/MSIE \d/) ? true : false
+    end
+
+    def ie_version(ua_string)
+      ua_string.match(/MSIE (\S+)/)[1].to_f
+    end
 
     def kick_it
       [301, {'Location' => @options[:redirect]}, 'Fail browser is fail']

test/noie6_test.rb

@@ -20,6 +20,13 @@ def test_redirects_to_where_it_should_if_ie6
     assert_equal response.location, 'http://slashdot.org'
   end
 
+  def test_redirects_to_where_it_should_if_user_specified_minimum_not_met
+    request  = Rack::MockRequest.new(Rack::NoIE6.new(TestApp.new, {:redirect => 'http://slashdot.org', :minimum => 6.0}))
+    response = request.get('/', {'HTTP_USER_AGENT' => 'Mozilla/4.0 (compatible; MSIE 5.5b1; Mac_PowerPC)' })
+    assert_equal 301, response.status
+    assert_equal response.location, 'http://slashdot.org'
+  end
+
   def test_redirects_to_local_urls
     request  = Rack::MockRequest.new(Rack::NoIE6.new(TestApp.new, {:redirect => '/foo'}))
     response = request.get('/foo', {'HTTP_USER_AGENT' => 'MSIE 6.0' })    
@@ -32,6 +39,18 @@ def test_allows_if_not_ie6
     assert_equal "Hi Internets!", response.body
   end
 
+  def test_allows_if_UA_version_greater_than_minimum
+    request  = Rack::MockRequest.new(Rack::NoIE6.new(TestApp.new, {:redirect => 'http://slashdot.org'}))
+    response = request.get('/', {'HTTP_USER_AGENT' => 'Mozilla/4.0 (compatible; MSIE 8.0; Windows XP)'})
+    assert_equal "Hi Internets!", response.body
+  end
+
+  def test_allows_if_no_UA_version_no_available
+    request  = Rack::MockRequest.new(Rack::NoIE6.new(TestApp.new, {:redirect => 'http://slashdot.org'}))
+    response = request.get('/', {'HTTP_USER_AGENT' => 'Mozilla/4.0 (compatible; MSIE l4me; Windows XP)'})
+    assert_equal "Hi Internets!", response.body
+  end
+
   def test_allows_if_no_user_agent_specified
     request  = Rack::MockRequest.new(Rack::NoIE6.new(TestApp.new, {:redirect => 'http://slashdot.org'}))
     response = request.get('/')