setup and expose logger

lib/sinatra/base.rb

@@ -149,6 +149,11 @@ module Sinatra
       request.session
     end
 
+    # Access shared logger object.
+    def logger
+      request.logger
+    end
+
     # Look up a media type by file extension in Rack's mime registry.
     def mime_type(type)
       Base.mime_type(type)
@@ -1232,8 +1237,8 @@ module Sinatra
       # an instance of this class as end point.
       def build(*args, &bk)
         builder = Rack::Builder.new
+        setup_logging builder
         builder.use Rack::Session::Cookie if sessions?
-        builder.use Rack::CommonLogger    if logging?
         builder.use Rack::MethodOverride  if method_override?
         builder.use ShowExceptions        if show_exceptions?
         middleware.each { |c,a,b| builder.use(c, *a, &b) }
@@ -1246,6 +1251,19 @@ module Sinatra
       end
 
     private
+      def setup_logging(builder)
+        if logging?
+          builder.use Rack::CommonLogger
+          if logging.respond_to? :to_int
+            builder.use Rack::Logger, logging
+          else
+            builder.use Rack::Logger
+          end
+        else
+          builder.use Rack::NullLogger
+        end
+      end
+
       def detect_rack_handler
         servers = Array(server)
         servers.each do |server_name|

test/helpers_test.rb

@@ -779,6 +779,36 @@ class HelpersTest < Test::Unit::TestCase
     end
   end
 
+  describe 'logger' do
+    it 'logging works when logging is enabled' do
+      mock_app do
+        enable :logging
+        get '/' do
+          logger.info "Program started"
+          logger.warn "Nothing to do!"
+        end
+      end
+      io = StringIO.new
+      get '/', {}, 'rack.errors' => io
+      assert io.string.include?("INFO -- : Program started")
+      assert io.string.include?("WARN -- : Nothing to do")
+    end
+
+    it 'logging works when logging is disable, but no output is produced' do
+      mock_app do
+        disable :logging
+        get '/' do
+          logger.info "Program started"
+          logger.warn "Nothing to do!"
+        end
+      end
+      io = StringIO.new
+      get '/', {}, 'rack.errors' => io
+      assert !io.string.include?("INFO -- : Program started")
+      assert !io.string.include?("WARN -- : Nothing to do")
+    end
+  end
+
   module ::HelperOne; def one; '1'; end; end
   module ::HelperTwo; def two; '2'; end; end