Rails 5.2 warns:
> The `success?` predicate is deprecated and will be removed in Rails 6.0.
> Please use `successful?` as provided by Rack::Response::Helpers.
RSpec correspondingly provides `be_successful`.
Raisl 5.1 removes support for non-keyword arguments in `#process`,
`#get`, `#post`, `#patch`, `#put`, `#delete`, and `#head` for the
`ActionDispatch::IntegrationTest` and `ActionController::TestCase`
classes. This means we have to add `params` everywhere in the controller
tests.
EventSchedule start time should be in hours range of the conference.Therefore it adds validation on start_time attribute of event schedule model. It also adds test for the same.
