Add quiet flag to server configuration (false by default)

It suppresses start and stop messages that Sinatra generates.
As requested here: #1148.

lib/sinatra/base.rb

@@ -1451,7 +1451,7 @@ def quit!
         return unless running?
         # Use Thin's hard #stop! if available, otherwise just #stop.
         running_server.respond_to?(:stop!) ? running_server.stop! : running_server.stop
-        $stderr.puts "== Sinatra has ended his set (crowd applauds)" unless handler_name =~/cgi/i
+        $stderr.puts "== Sinatra has ended his set (crowd applauds)" unless supress_messages?
         set :running_server, nil
         set :handler_name, nil
       end
@@ -1533,7 +1533,7 @@ def caller_locations
       # Starts the server by running the Rack Handler.
       def start_server(handler, server_settings, handler_name)
         handler.run(self, server_settings) do |server|
-          unless handler_name =~ /cgi/i
+          unless supress_messages?
             $stderr.puts "== Sinatra (v#{Sinatra::VERSION}) has taken the stage on #{port} for #{environment} with backup from #{handler_name}"
           end
 
@@ -1546,6 +1546,10 @@ def start_server(handler, server_settings, handler_name)
         end
       end
 
+      def supress_messages?
+        handler_name =~ /cgi/i || quiet
+      end
+
       def setup_traps
         if traps?
           at_exit { quit! }
@@ -1801,6 +1805,7 @@ class << self
     set :server, %w[HTTP webrick]
     set :bind, Proc.new { development? ? 'localhost' : '0.0.0.0' }
     set :port, Integer(ENV['PORT'] && !ENV['PORT'].empty? ? ENV['PORT'] : 4567)
+    set :quiet, false
 
     ruby_engine = defined?(RUBY_ENGINE) && RUBY_ENGINE
 

lib/sinatra/main.rb

@@ -17,6 +17,7 @@ class Application < Base
         op.on('-o addr',   "set the host (default is #{bind})")             { |val| set :bind, val }
         op.on('-e env',    'set the environment (default is development)')  { |val| set :environment, val.to_sym }
         op.on('-s server', 'specify rack server/handler (default is thin)') { |val| set :server, val }
+        op.on('-q',        'turn on quiet mode (default is off)')           {       set :quiet, true }
         op.on('-x',        'turn on the mutex lock (default is off)')       {       set :lock, true }
       }.parse!(ARGV.dup)
     end

test/server_test.rb

@@ -53,4 +53,18 @@ def teardown
   it "falls back on the next server handler when not found" do
     @app.run! :server => %w[foo bar mock]
   end
+
+  describe "Quiet mode" do
+    it "sends data to stderr when server starts and stops" do
+      @app.run!
+      assert_match(/\=\= Sinatra/, $stderr.string)
+    end
+
+    context "when quiet mode is activated" do
+      it "does not generate Sinatra start and stop messages" do
+        @app.run! quiet: true
+        refute_match(/\=\= Sinatra/, $stderr.string)
+      end
+    end
+  end
 end