make AcceptEntry behave like string

lib/sinatra/base.rb

@@ -71,9 +71,10 @@ module Sinatra
           [key, value]
         end
 
-        @type = entry[/[^;]+/].delete(' ')
+        @entry  = entry
+        @type   = entry[/[^;]+/].delete(' ')
         @params = Hash[params]
-        @q = @params.delete('q') { "1.0" }.to_f
+        @q      = @params.delete('q') { "1.0" }.to_f
       end
 
       def <=>(other)
@@ -85,13 +86,21 @@ module Sinatra
         [ @q, -@type.count('*'), @params.size ]
       end
 
-      def [](param)
-        @params[param]
-      end
-
       def to_str
         @type
       end
+
+      def to_s(full = false)
+        full ? entry : to_str
+      end
+
+      def respond_to?(*args)
+        super or to_str.respond_to?(*args)
+      end
+
+      def method_missing(*args, &block)
+        to_str.send(*args, &block)
+      end
     end
   end
 

test/request_test.rb

@@ -50,6 +50,17 @@ class RequestTest < Test::Unit::TestCase
     assert_equal({ 'compress' => '0.25' }, request.preferred_type.params)
   end
 
+  it "makes accept types behave like strings" do
+    request = Sinatra::Request.new('HTTP_ACCEPT' => 'image/jpeg; compress=0.25')
+    assert_equal 'image/jpeg', request.preferred_type.to_s
+    assert_equal 'image/jpeg', request.preferred_type.to_str
+    assert_equal 'image',      request.preferred_type.split('/').first
+
+    String.instance_methods.each do |method|
+      assert request.preferred_type.respond_to? method
+    end
+  end
+
   it "properly decodes MIME type parameters" do
     request = Sinatra::Request.new(
       'HTTP_ACCEPT' => 'image/jpeg;unquoted=0.25;quoted="0.25";chartest="\";,\x"'