add QuietLogger that excludes pathes from Rack::CommonLogger (#1250)

sinatra-contrib/README.md

@@ -67,6 +67,9 @@ Currently included:
 * [`sinatra/test_helpers`][sinatra-test-helpers]: Helper methods to ease testing your Sinatra
   application. Partly extracted from Sinatra. Testing framework agnostic
 
+* `sinatra/quiet_logger`: Extension to exclude specific pathes from access log.
+  It works by patching Rack::CommonLogger
+
 ## Installation
 
 Add `gem 'sinatra-contrib'` to *Gemfile*, then execute `bundle install`.

sinatra-contrib/lib/sinatra/quiet_logger.rb

@@ -0,0 +1,37 @@
+module Sinatra
+  # = Sinatra::QuietLogger
+  #
+  # QuietLogger extension allows you to define pathes excluded
+  # from logging using the +quiet_logger_prefixes+ setting.
+  # It is inspired from rails quiet_logger, but handles multiple pathes.
+  #
+  # == Usage
+  #
+  # You have to require the quiet_logger, set the setting
+  # and register the extension in your application.
+  #
+  #     require 'sinatra/base'
+  #     require 'sinatra/quiet_logger'
+  #
+  #     set :quiet_logger_prefixes, %w(css js images fonts)
+  #
+  #     class App < Sinatra::Base
+  #       register Sinatra::QuietLogger
+  #     end
+  module QuietLogger
+
+    def self.registered(app)
+      quiet_logger_prefixes = app.settings.quiet_logger_prefixes.join('|') rescue ''
+      return warn('You need to specify the pathes you wish to exclude from logging via `set :quiet_logger_prefixes, %w(images css fonts)`') if quiet_logger_prefixes.empty?
+      const_set('QUIET_LOGGER_REGEX', %r(\A/{0,2}(?:#{quiet_logger_prefixes})))
+      ::Rack::CommonLogger.prepend(
+        ::Module.new do
+          def log(env, *)
+            super unless env['PATH_INFO'] =~ QUIET_LOGGER_REGEX
+          end
+        end
+      )
+    end
+
+  end
+end

sinatra-contrib/spec/quiet_logger_spec.rb

@@ -0,0 +1,34 @@
+require 'spec_helper'
+require 'sinatra/quiet_logger'
+require 'logger'
+
+describe Sinatra::QuietLogger do
+
+  it 'logs just pathes not excluded' do
+    log = StringIO.new
+    logger = Logger.new(log)
+    mock_app do
+      use Rack::CommonLogger, logger
+      set :quiet_logger_prefixes, %w(quiet asset)
+      register Sinatra::QuietLogger
+      get('/log') { 'in log' }
+      get('/quiet') { 'not in log' }
+    end
+
+    get('/log')
+    get('/quiet')
+
+    str = log.string
+    expect(str).to include('GET /log')
+    expect(str).to_not include('GET /quiet')
+  end
+
+  it 'warns about not setting quiet_logger_prefixes' do
+    expect {
+      mock_app do
+        register Sinatra::QuietLogger
+      end
+    }.to output("You need to specify the pathes you wish to exclude from logging via `set :quiet_logger_prefixes, %w(images css fonts)`\n").to_stderr
+  end
+
+end