Add additional context to background exception notifications

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    exception_notification (2.4.1)
+    exception_notification (2.5.2)
       actionmailer (>= 3.0.4)
 
 GEM

lib/exception_notifier/notifier.rb

@@ -70,12 +70,13 @@ def exception_notification(env, exception)
       end
     end
 
-    def background_exception_notification(exception)
+    def background_exception_notification(exception, additional = {})
       if @notifier = Rails.application.config.middleware.detect{ |x| x.klass == ExceptionNotifier }
         @options = (@notifier.args.first || {}).reverse_merge(self.class.default_options)
         @exception = exception
         @backtrace = exception.backtrace || []
-        @sections  = %w{backtrace}
+        @additional_context = additional
+        @sections  = %w(additional_context backtrace)
         subject  = compose_subject(exception)
 
         mail(:to => @options[:exception_recipients], :from => @options[:sender_address], :subject => subject) do |format|

lib/exception_notifier/views/exception_notifier/_additional_context.text.erb

@@ -0,0 +1,4 @@
+<% max = @additional_context.keys.max { |a, b| a.length <=> b.length } -%>
+<% @additional_context.keys.sort.each do |key| -%>
+* <%= raw("%-*s: %s" % [max.length, key, inspect_object(@additional_context[key])]) %>
+<% end -%>

test/background_exception_notification_test.rb

@@ -3,10 +3,11 @@
 class BackgroundExceptionNotificationTest < ActiveSupport::TestCase
   setup do
     begin
+      @troublesome_object = "I like to cause problems."
       1/0
     rescue => e
       @exception = e
-      @mail = ExceptionNotifier::Notifier.background_exception_notification(@exception)
+      @mail = ExceptionNotifier::Notifier.background_exception_notification(@exception, :the_trouble_object => @troublesome_object)
     end
   end
 
@@ -34,8 +35,12 @@ class BackgroundExceptionNotificationTest < ActiveSupport::TestCase
     assert @mail.body.include? "A ZeroDivisionError occurred in background"
   end
 
+  test "mail should contain additional context" do
+    assert @mail.body.include? "I like to cause problems."
+  end
+
   test "mail should contain backtrace in body" do
-    assert @mail.body.include? "test/background_exception_notification_test.rb:6"
+    assert @mail.body.include? "test/background_exception_notification_test.rb:"
   end
 
   test "mail should not contain any attachments" do