ExceptionManager
Gem for better exception recording.
Installation
Add this line to your application's Gemfile:
gem 'exception_manager'And then execute:
$ bundle
Or install it yourself as:
$ gem install exception_manager
Usage
First of all, make sure that ExceptionManager is enabled in your application.
# config/initializers/exception_manager.rb
ExceptionManager.enable!That's it! Now you can use it.
class TestClassThatRaisesException
@@class_variable = :class_value
def test_error(*args)
@instance_variable = :instance_value
raise 'Test error'
end
end
begin
TestClassThatRaisesException.new.test_error(1, 2, 3)
rescue => e
puts "Subject: #{e.subject}"
puts "Locals: #{e.locals}"
puts "Instance variables: #{e.subject_instance_variables}"
puts "Class variables: #{e.subject_class_variables}"
puts "Summary: #{e.summary.inspect}"
endAnd if you have pry, you can combine it:
e._binding.pryIntegration with monitoring systems like NewRelic
NewRelic uses to_s method for fetching message from exception:
source.
Unfortunately you cannot override to_s method like this:
# DO NOT ADD THIS CODE TO YOUR PROJECT
# IF YOU DON'T WANT TO GET SEGFAULT
class YourApiBaseException < StandardError
def to_s
[super, summary.inspect].join(' ')
end
endThe solution is in this line: source
Instead of overriding to_s method we can override original_exception method:
# This code is safe
class YourApiBaseException < StandardError
def original_exception
message_for_new_relic = [message, summary.inspect].join(' ')
self.exception(message_for_new_relic)
end
endFrom this moment all exceptions inherited from YourApiBaseException will have message
with exception summary:
begin
raise YourApiBaseException, 'my custom message'
rescue YourApiBaseException => e
puts e.original_exception.to_s # this is exactly what NewRelic gem calls
end
# => 'my custom message {:locals=>..., :subject=>..., }'Other systems may use message method, so the code will look like:
class YourApiBaseException < StandardError
def message
[super, summary.inspect].join(' ')
end
endIf you don't know exactly which method is used in your monitoring system, you can simply override both π
Contributing
- Fork it ( https://github.com/[my-github-username]/exception_manager/fork )
- Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create a new Pull Request