Avoid noise when code runs with Ruby warnings

[cpetschnig]

New versions of RSpec have warnings turned on by default:

# This setting enables warnings. It's recommended, but in some cases may
# be too noisy due to issues in dependencies.
config.warnings = true

I believe these warnings are helpful in general to write better code. However, Grape and Grape Entity are very noisy. I get about 20 lines of warnings for one single test where Grape is involved.

I hope you agree. Many of my changes could also be solved differently for sure. I am happy to discuss and change those cases. I also changed the specs for less warnings and turned them on in the test suite.

[dblock]

I think initializers such as @status ||= nil should be @status = nil in def initialize. Otherwise this looks sensible.

[cpetschnig]

I have done so in all the classes. The cases where I didn't are all modules in the DSL namespace.

[dblock]

Because those are included? I am not a huge fan of side-effects of assigning something on return to nil, warning or convention or not. Anyone else has an opinion, maybe @namusyaka or @LeFnord?

[cpetschnig]

I agree that @body ||= nil is not a very good pattern, rather hard to read/understand. I removed the two occurrences from the PR.

[dm1try]

Sorry to bother you guys, I'm personally 👎 for this.
I prefer to move "instance variable @var not initialized" warning to the other verbosity level than add more code to deal with it :)
bundle exec ruby -Ispec -W2 spec/grape/validations/validators/default_spec.rb - I'll happy to see it only here.

There are some good points in the sequel repo that can help with the decision.

[cpetschnig]

The discussion in the sequel repo is very interesting, also the references to the Ruby development. The warning gem in Ruby 2.4 will definitely help. The sequel gem should be a good reference.

I see that some of my changes may affect the performance of every API call, while others are only executed when the app is started. What do you think of changing only the occurrences in start-up code?

[dblock]

I would be down with what you're proposing @cpetschnig. Initialization in def initialize is ok with me, but side effects in properties aren't.

[cpetschnig]

I updated the PR:
Instance variables are now only initialized in def initialize. Also removed the config.warning = true from spec_helper.rb.

[dm1try]

maybe Base class is a better place for this

[cpetschnig]

Very true, I've changed it.

[dm1try]

It's very good, thanks @cpetschnig!

[LeFnord]

🎉

[dblock]

Perfect, thanks!