Do not attempt to convert ActionDispatch::Request/Response to JSON

[alpaca-tc]

Since Rails 6.1, the payload of action dispatch can't be converted.

It's not guaranteed to_json conversion, and SystemStackError got to happen.
To avoid this, fixed to ignore ActionDispatch::Request/ActionDispatch::Response to JSON.

and added test for rails 6.1

[epistrephein]

Any chance to get a review/merge and a new gem version for this fix?

[zzemla]

For anyone interested - a monkey patch based on this PR, which you can put into a file under config/initializers:

if defined?(MetaRequest) && ! MetaRequest::Event.private_instance_methods(false).include?(:not_encodable?)

  MetaRequest::Event.class_eval {

    private

    def json_encodable(payload)
      return {} unless payload.is_a?(Hash)

      transform_hash(payload, deep: true) do |hash, key, value|
        if value.class.to_s == 'ActionDispatch::Http::Headers'
          value = value.to_h.select { |k, _| k.upcase == k }
        elsif not_encodable?(value)
          value = self.class.const_get(:NOT_JSON_ENCODABLE)
        end

        begin
          value.to_json(methods: [:duration])
          new_value = value
        rescue StandardError
          new_value = self.class.const_get(:NOT_JSON_ENCODABLE)
        end
        hash[key] = new_value
      end.with_indifferent_access
    end

    def not_encodable?(value)
      (defined?(ActiveRecord) && value.is_a?(ActiveRecord::ConnectionAdapters::AbstractAdapter)) ||
        (defined?(ActionDispatch) &&
          (value.is_a?(ActionDispatch::Request) || value.is_a?(ActionDispatch::Response)))
    end

  }

end

[dejan]

Thanks for the fix!