After like 3 weeks of not touching code I decided to refresh my pet project a little bit, below are random issues you might encounter while trying to upgrade your old Rails 4 app to Rails 5.

  1. uninitialized constant ActionController::RedirectBackError
  1. Returning false in before_save callback doesn’t halt it (old kinda specific Rails gotcha/behavior).
  1. NoMethodError: super: no superclass method xhr for RSpec::ExampleGroups::<controller>
  1. render nothing: true tries to render template
  1. ArgumentError: unknown keyword: <key>
  1. No method error on object.errors.get(:field)