grape 2.2.0 is incompatible with grape-rabl

[znz]

grape-rabl 0.5.0 uses Grape::Formatter.formatter_for with one argument.

grape-rabl/lib/grape-rabl/formatter.rb

Lines 40 to 41 in b201ebd

	def fallback_formatter
	Grape::Formatter.formatter_for(env[Grape::Env::API_FORMAT])

But grape 2.2.0 changed its arity.

ruby-grape/grape@v2.1.3...v2.2.0#diff-2332fb7b55e286e39346d06d8427673ae0dade2d41786327b23375cc30ef2ffaR17

So wrong number of arguments (given 1, expected 2) raised.

In our application, following monkey patch resolved the exception.

module Grape
  module Formatter
    module_function

    def formatter_for(api_format, formatters=nil)
      select_formatter(formatters, api_format) || DEFAULT_LAMBDA_FORMATTER
    end
  end
end

[dblock]

I am moving this to grape-rabl since it's really a problem with the latter.

Want to try and fix this here? Maybe start with #52.