Make common_logger plugin handle raised errors

Internal after hooks are always called inside an ensure block,
even if there is no rack response.  So plugins that use internal
after hooks need to handle the case where there is no rack response.

CHANGELOG

@@ -1,3 +1,7 @@
+= master
+
+* Make common_logger plugin handle raised errors (jeremyevans)
+
 = 3.12.0 (2018-09-14)
 
 * Add common_logger plugin for common log support (jeremyevans)

lib/roda/plugins/common_logger.rb

@@ -47,6 +47,8 @@ module InstanceMethods
 
         # Log request/response information in common log format to logger.
         def _roda_after_90__common_logger(result)
+          return unless result && result[0] && result[1]
+
           elapsed_time = if timer = @_request_timer
             '%0.4f' % (CommonLogger.start_timer - timer)
           else 

spec/plugin/common_logger_spec.rb

@@ -56,4 +56,30 @@ def cl_app(&block)
     @logger.rewind
     @logger.read.must_match /\A- - - \[\d\d\/[A-Z][a-z]{2}\/\d\d\d\d:\d\d:\d\d:\d\d [-+]\d\d\d\d\] "GET \/ " 500 - 0.\d\d\d\d\n\z/
   end
+
+  it 'does not log if an error is raised' do
+    cl_app do |r|
+      raise "foo"
+    end
+
+    begin
+      body
+    rescue => e
+    end
+    e.must_be_instance_of(RuntimeError)
+    e.message.must_equal 'foo'
+  end
+
+  it 'logs errors if used with error_handler' do
+    cl_app do |r|
+      raise "foo"
+    end
+    @app.plugin :error_handler do |_|
+      "bad"
+    end
+
+    body.must_equal 'bad'
+    @logger.rewind
+    @logger.read.must_match /\A- - - \[\d\d\/[A-Z][a-z]{2}\/\d\d\d\d:\d\d:\d\d:\d\d [-+]\d\d\d\d\] "GET \/ " 500 3 0.\d\d\d\d\n\z/
+  end
 end