Suppress Ruby warnings when running specs

Question

I'm looking for a way to suppress Ruby warnings when I run my specs.

spec spec/models/account_spec.rb

I receive warnings such as:

DEPRECATION WARNING: ActiveSupport::Dependencies.load_paths is deprecated, ...
warning: already initialized constant SOME_CONSTANT_NAME

Removing the ActiveSupport warning is quite easy with ActiveSupport::Deprecation.silenced = true.

How do I prevent the already initialized constant warnings as part of my spec command? Or through creating another spec file that can suppress such warnings. Keep in mind that these warnings are from gem files, therefore I cannot go into those files and surround them with Kernel.silence_warnings.

Note: I understand that suppressing warnings are bad. However, when I run a single spec from within vim it would be nice if the warnings didn't clutter my screen.

Solution 1

If you run your specs directly with the ruby command instead of the spec wrapper, you can use the -W command line option to silence warnings:

$ ruby --help
[...]
  -W[level]       set warning level; 0=silence, 1=medium, 2=verbose (default)

So in your case:

$ ruby -W0 -Ispec spec/models/event_spec.rb

should not show you any warnings.

Alternatively, you could set $VERBOSE=nil before your gems are loaded, ie at the top of your environment.rb (or application.rb if you're on Rails 3). Note that this disables all warnings all the time.

Or, since you are using Rails, you should be able to use Kernel.silence_warnings around the Bundler.require block if you're using Bundler:

Kernel.silence_warnings do
  Bundler.require(:default, Rails.env) if defined?(Bundler)
end

More selectively, set $VERBOSE only for loading specific gems:

config.gem 'wellbehaving_gem'
original_verbosity = $VERBOSE
$VERBOSE = nil
config.gem 'noisy_gem_a'
$VERBOSE = original_verbosity

Solution 2

The syntax for RUBYOPT is

RUBYOPT="-W0" rspec

Tested in ruby 2.1.x and 2.14.x

Solution 3

Related with this post, you can manage deprecation warnings according to th environment in which you are working, as said in rails guides:

active_support.deprecation_behavior Sets up deprecation reporting for environments, defaulting to :log for development, :notify for production and :stderr for test. If a value isn't set for config.active_support.deprecation then this initializer will prompt the user to configure this line in the current environment's config/environments file. Can be set to an array of values.

So just change in config/environments/test.rb the value :stderr for :log

Rails.application.configure do
   ...
   # Print deprecation notices to the log file instead of console.
   config.active_support.deprecation = :log
   ...
end

And with this change, the deprecation warnings will now be printed to the log/test.log instead of the console output.

Solution 4

You can also use the "RUBYOPT" environment variable to pass -W0 to rspec:

RUBYOPT=W0 rspec spec/models/event_spec.rb

This allows you to run multiple specs by passing in a directory

RUBYOPT=W0 rspec spec/models

Solution 5

Putting Warning[:deprecated] = false after require "rails/all" in config/application.rb works very well to suppress those warnings everywhere. You can do

Warning[:deprecated] = false if Rails.env.test?

for your particular case, or better yet - put it in config/environments/test.rb, but I'm not sure how well it is going to work since I belive some stuff is loaded before that.

View more solutions

Comments

[Jey Balachandran]

Is there a way to check if -W0 was set from within the Ruby file?

[Jakob S]

Yeah, just check the value of $VERBOSE. -W0 => nil, -W1 => false, -W2 => true

[Richard Nienaber]

I had to use Dingle's answer for Ruby 2.2.2.

[Evgenia Karunus]

and also works for minitest: RUBYOPT=W0 rake test TEST=test/hi_test.rb.

[PhilT]

Thanks, Adding $VERBOSE = nil to my Rakefile silenced warnings for me.

[n13]

This was the only solution that worked for me - passing -W0 did nothing.

[brauliobo]

there is no --warnings there obviously

[Glenn]

"export RUBYOPT=-W0 " worked for me as a general solution.