wrong number of arguments (given 2, expected 1)

[gogainda]

latest grape gem fails in multiple places with the same error :

Failures:

  1) Grape::Middleware::Auth::Strategies Digest MD5 Auth authenticates if given valid creds
     �[31mFailure/Error: builder.to_app�[0m
     �[31m�[0m
     �[31mArgumentError:�[0m
     �[31m  wrong number of arguments (given 2, expected 1)�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-2.2.3/lib/rack/head.rb:7:in `initialize'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-2.2.3/lib/rack/builder.rb:158:in `new'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-2.2.3/lib/rack/builder.rb:158:in `block in use'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-2.2.3/lib/rack/builder.rb:235:in `[]'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-2.2.3/lib/rack/builder.rb:235:in `block in to_app'�[0m
     �[36m# <internal:core> core/enumerable.rb:465:in `inject'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-2.2.3/lib/rack/builder.rb:235:in `to_app'�[0m
     �[36m# ./lib/grape/endpoint.rb:323:in `build_stack'�[0m
     �[36m# ./lib/grape/endpoint.rb:355:in `block in lazy_initialize!'�[0m
     �[36m# ./lib/grape/endpoint.rb:351:in `synchronize'�[0m
     �[36m# ./lib/grape/endpoint.rb:351:in `lazy_initialize!'�[0m
     �[36m# ./lib/grape/endpoint.rb:224:in `call'�[0m
     �[36m# ./lib/grape/router/route.rb:58:in `exec'�[0m
     �[36m# ./lib/grape/router.rb:116:in `process_route'�[0m
     �[36m# ./lib/grape/router.rb:72:in `block in identity'�[0m
     �[36m# ./lib/grape/router.rb:91:in `transaction'�[0m
     �[36m# ./lib/grape/router.rb:70:in `identity'�[0m
     �[36m# ./lib/grape/router.rb:55:in `block in call'�[0m
     �[36m# ./lib/grape/router.rb:132:in `with_optimization'�[0m
     �[36m# ./lib/grape/router.rb:54:in `call'�[0m
     �[36m# ./lib/grape/api/instance.rb:167:in `call'�[0m
     �[36m# ./lib/grape/api/instance.rb:71:in `call!'�[0m
     �[36m# ./lib/grape/api/instance.rb:66:in `call'�[0m
     �[36m# ./lib/grape/api.rb:68:in `call'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-test-1.1.0/lib/rack/mock_session.rb:29:in `request'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-test-1.1.0/lib/rack/test.rb:266:in `process_request'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-test-1.1.0/lib/rack/test.rb:129:in `custom_request'�[0m
     �[36m# /home/travis/.rvm/gems/truffleruby-head/gems/rack-test-1.1.0/lib/rack/test.rb:58:in `get'�[0m
     �[36m# /home/travis/.rvm/rubies/truffleruby-head/lib/mri/forwardable.rb:235:in `get'�[0m
     �[36m# ./spec/grape/middleware/auth/strategies_spec.rb:72:in `block (3 levels) in <top (required)>'�[0m

full logs could be found here

[eregon]

@gogainda Thanks for the report.
I'm not sure what you use to copy-paste, but it seems to introduce extra blank lines which is rather noisy. Could you try to fix for new bug reports?

This seems to likely be an extra empty Hash passed to initialize, so probably we need the 2.7 semantics of **hash passing nothing to fix this + handling ruby2_keywords.
https://github.com/rack/rack/blob/2.2.3/lib/rack/head.rb#L7
https://github.com/rack/rack/blob/2.2.3/lib/rack/builder.rb#L158-L160
https://github.com/rack/rack/blob/2.2.3/lib/rack/builder.rb#L235
https://github.com/ruby-grape/grape/blob/42489c243c78761238093c40f5af2b2bb9a05580/lib/grape/endpoint.rb#L286-L323

[eregon]

I'd guess this code causes this: https://github.com/ruby-grape/grape/blob/42489c243c78761238093c40f5af2b2bb9a05580/lib/grape/middleware/stack.rb#L35-L45
It uses *args, **opts-delegation, which is not correct in some cases on 2.7.
It should use ruby2_keywords instead.

[eregon]

Failures fixed by ruby-grape/grape#2132 upstream.

For the remaining keyword arguments changes for 2.7, they are tracked in #2004.