exception_event.rb in timber-2.1.0.rc1

- old
+ new
@@ -1,28 +1,61 @@
+begin
+  require "action_dispatch/middleware/exception_wrapper"
+rescue Exception
+end
+
+require "timber/integrations/rack/middleware"
+
 module Timber
   module Integrations
     module Rack
-      # Reponsible for capturing exceptions events within a Rack stack.
-      class ExceptionEvent
-        def initialize(app)
-          @app = app
+      # A Rack middleware that is reponsible for capturing exceptions events
+      # {Timber::Events::Exception}.
+      class ExceptionEvent < Middleware
+        # We determine this when the app loads to avoid the overhead on a per request basis.
+        EXCEPTION_WRAPPER_TAKES_CLEANER = if Gem.loaded_specs["rails"]
+          Gem.loaded_specs["rails"].version >= Gem::Version.new('5.0.0')
+        else
+          false
         end
 
         def call(env)
           begin
             status, headers, body = @app.call(env)
           rescue Exception => exception
             Config.instance.logger.fatal do
+              backtrace = extract_backtrace(env, exception)
+
               Events::Exception.new(
                 name: exception.class.name,
                 exception_message: exception.message,
-                backtrace: exception.backtrace
+                backtrace: backtrace
               )
             end
 
             raise exception
           end
         end
+
+        private
+          # Rails provides a backtrace cleaner, so we use it here.
+          def extract_backtrace(env, exception)
+            if defined?(::ActionDispatch::ExceptionWrapper)
+              wrapper = if EXCEPTION_WRAPPER_TAKES_CLEANER
+                request = Util::Request.new(env)
+                backtrace_cleaner = request.get_header("action_dispatch.backtrace_cleaner")
+                ::ActionDispatch::ExceptionWrapper.new(backtrace_cleaner, exception)
+              else
+                ::ActionDispatch::ExceptionWrapper.new(env, exception)
+              end
+
+              trace = wrapper.application_trace
+              trace = wrapper.framework_trace if trace.empty?
+              trace
+            else
+              exception.backtrace
+            end
+          end
       end
     end
   end
 end
\ No newline at end of file