--warnings option (run with warnings enabled)

Use the --warnings option to run specs with warnings enabled.

Given a file named "example_spec.rb" with:

RSpec.describe do
  it 'generates warning' do
    $undefined
  end
end

When I run rspec --warnings example_spec.rb

Then the output should contain "warning".

Given a file named "example_spec.rb" with:

def foo(**kwargs)
  kwargs
end

RSpec.describe do
 it "should warn about keyword arguments with 'rspec -w'" do
   expect(foo({a: 1})).to eq({a: 1})
  end
end

When I run rspec -w example_spec.rb

Then the output should contain "warning".

Given a file named "example_spec.rb" with:

RSpec.describe do
  it 'generates warning' do
    $undefined
  end
end

When I run rspec example_spec.rb

Then the output should not contain "warning".