Freeze omniauth in test to verify thread safety

Gemfile

@@ -20,6 +20,7 @@ group :test do
   gem 'rack-test'
   gem 'rest-client', '~> 2.0.0', :platforms => [:jruby_18]
   gem 'rspec', '~> 3.5'
+  gem 'rack-freeze'
   gem 'rubocop', '>= 0.58.2', '< 0.69.0', :platforms => %i[ruby_20 ruby_21 ruby_22 ruby_23 ruby_24]
   gem 'simplecov-lcov'
   gem 'tins', '~> 1.13', :platforms => %i[jruby_18 jruby_19 ruby_19]

spec/helper.rb

@@ -20,6 +20,7 @@ end
 
 require 'rspec'
 require 'rack/test'
+require 'rack/freeze'
 require 'omniauth'
 require 'omniauth/test'
 

spec/omniauth/builder_spec.rb

@@ -121,14 +121,11 @@ describe OmniAuth::Builder do
 
   describe '#call' do
     it 'passes env to to_app.call' do
-      app = lambda { |_env| [200, {}, []] }
+      app = lambda { |env| [200, {}, env['CUSTOM_ENV_VALUE']] }
       builder = OmniAuth::Builder.new(app)
-      env = {'REQUEST_METHOD' => 'GET', 'PATH_INFO' => '/some/path'}
-      allow(app).to receive(:call).and_call_original
+      env = {'REQUEST_METHOD' => 'GET', 'PATH_INFO' => '/some/path', 'CUSTOM_ENV_VALUE' => 'VALUE'}
 
-      builder.call(env)
-
-      expect(app).to have_received(:call).with(env)
+      expect(builder.call(env)).to eq([200, {}, 'VALUE'])
     end
   end