**nil no keyword mark method definitions

[moofkit]

Solving #745

**nil is allowed in method definitions to explicitly mark
that the method accepts no keywords. Calling such a method with keywords
will result in an ArgumentError. Feature #14183

PS I'm not sure that it is correct place for spec...

[andrykonchin]

Looks good 👍 .

Wondering why this new spec is under guard ruby_version_is "2.7"...'3.0' instead of ruby_version_is "2.7"...''. Is there any reason to declare the upper version?

spec/language/method_spec.rb

Line 1170 in 648f40b

ruby_version_is "2.7"...'3.0' do

[moofkit]

@andrykonchin thank you for review!
I have found some a little details about this feature here https://www.ruby-lang.org/en/news/2019/12/12/separation-of-positional-and-keyword-arguments-in-ruby-3-0/
Yeah, I think you are right and it is should be under ruby_version_is "2.7"...'' guard.

But there are no such guard yet in this spec. Should I add it?

[moofkit]

Ahh, I see https://github.com/ruby/spec/blob/master/CONTRIBUTING.md#version-guards

ruby_version_is "2.7" do
  # Specs for RUBY_VERSION >= 2.7
end

[moofkit]

@andrykonchin moved spec under ruby_version_is "2.7" guard.

After several moving and reading specs context I've decide to leave it under separated guard block. Commits was squashed for clear history

[andrykonchin]

Great. Thank you for the new specs!