Grape is failing on latest Rack releases.

[ioquatix]

Failures:

  1) Grape::Endpoint#params from body parameters returns a 400 if given an invalid multipart body
     Failure/Error: @params_builder.call(rack_params).deep_merge!(grape_routing_args)

     Rack::Multipart::BoundaryTooLongError:
       multiple boundary parameters found in multipart content type
     # /home/runner/work/rack/rack/lib/rack/multipart/parser.rb:131:in 'Rack::Multipart::Parser.parse_boundary'

It looks like the test constructs two boundary parameters which is invalid. You might need to catch Rack::Multipart::Error.

[samuel-williams-shopify]

Probably you need to rescue Rack::Multipart::Error here:

grape/lib/grape/request.rb

Lines 167 to 179 in ec1b0fe

	def make_params
	@params_builder.call(rack_params).deep_merge!(grape_routing_args)
	rescue EOFError
	raise Grape::Exceptions::EmptyMessageBody.new(content_type)
	rescue Rack::Multipart::MultipartPartLimitError, Rack::Multipart::MultipartTotalPartLimitError
	raise Grape::Exceptions::TooManyMultipartFiles.new(Rack::Utils.multipart_part_limit)
	rescue Rack::QueryParser::ParamsTooDeepError
	raise Grape::Exceptions::TooDeepParameters.new(Rack::Utils.param_depth_limit)
	rescue Rack::Utils::ParameterTypeError
	raise Grape::Exceptions::ConflictingTypes
	rescue Rack::Utils::InvalidParameterError
	raise Grape::Exceptions::InvalidParameters
	end

or somewhere similar.

[ericproulx]

@ioquatix this PR should fix it and is future proof