failing test custom validator keeping ref to instance var

spec/grape/api/custom_validations_spec.rb

@@ -3,6 +3,54 @@
 require 'spec_helper'
 
 describe Grape::Validations do
+
+ context "when a validator uses an instance variable" do
+ before do
+ module CustomValidationsSpec
+ module HelperMethods
+ extend Grape::API::Helpers
+ def max_ref(req_params)
+ return @max unless @max.nil?
+ @max = req_params[:max].to_i
+ end
+ end
+
+ class DefaultLength < Grape::Validations::Base
+ include CustomValidationsSpec::HelperMethods
+ def validate_param!(attr_name, params)
+ return if params[attr_name].length <= max_ref(params)
+ fail Grape::Exceptions::Validation, params: [@scope.full_name(attr_name)], message: "must be at the most #{max_ref(params)} characters long"
+ end
+ end
+ end
+ end
+
+ subject do
+ Class.new(Grape::API) do
+ params do
+ requires :text, default_length: 140
+ requires :max
+ end
+ get do
+ 'bacon'
+ end
+ end
+ end
+
+ def app
+ subject
+ end
+
+ it 'between 2 calls, helper inside a validator does not keep old reference of instance variable' do
+ get '/', text: 'a' * 130, max: 140
+ expect(last_response.status).to eq 200
+
+ get '/', text: 'a' * 130, max: 120
+ expect(last_response.status).to eq 400
+ end
+ end
+
+
  context 'using a custom length validator' do
  before do
  module CustomValidationsSpec