Improves error handling behavior. Closes #578.

* OmniAuth::FailureEndpoint will raise any encountered
  errors out if RACK_ENV is development.
* It will redirect compatibly with current OmniAuth if
  not in development.
* Now uses Rack::Response to include a content length
  in the failure response.

.rspec

@@ -1,2 +1,2 @@
 --color
---order random
+--order random

Gemfile

@@ -1,4 +1,13 @@
 source 'https://rubygems.org'
 
 gem 'rack', '~> 1.4'
+gem 'growl'
+gem 'guard'
+gem 'guard-bundler'
+gem 'guard-rspec'
+gem 'pry'
+gem 'pry-nav'
+gem 'plymouth'
+gem 'rb-fsevent'
+    
 gemspec

lib/omniauth.rb

@@ -2,6 +2,8 @@ require 'rack'
 require 'singleton'
 
 module OmniAuth
+  class Error < StandardError; end
+  
   module Strategies
     autoload :Developer, 'omniauth/strategies/developer'
   end

lib/omniauth/failure_endpoint.rb

@@ -1,4 +1,10 @@
 module OmniAuth
+  # This simple Rack endpoint that serves as the default
+  # 'failure' mechanism for OmniAuth. If a strategy fails for
+  # any reason this endpoint will be invoked. The default behavior
+  # is to redirect to `/auth/failure` except in the case of
+  # a development `RACK_ENV`, in which case an exception will
+  # be raised.
   class FailureEndpoint
     attr_reader :env
 
@@ -11,9 +17,18 @@ module OmniAuth
     end
 
     def call
+      raise_out! if ENV['RACK_ENV'].to_s == 'development'
+      redirect_to_failure
+    end
+
+    def raise_out!
+      raise env['omniauth.error'] || OmniAuth::Error.new(env['omniauth.error.type']) 
+    end
+
+    def redirect_to_failure
       message_key = env['omniauth.error.type']
       new_path = "#{env['SCRIPT_NAME']}#{OmniAuth.config.path_prefix}/failure?message=#{message_key}"
-      [302, {'Location' => new_path, 'Content-Type'=> 'text/html'}, []]
+      Rack::Response.new(["302 Moved"], 302, 'Location' => new_path).finish
     end
   end
 end

omniauth.gemspec

@@ -10,14 +10,9 @@ Gem::Specification.new do |gem|
   gem.add_runtime_dependency 'rack'
   gem.add_runtime_dependency 'hashie', '~> 1.2'
 
-  gem.add_development_dependency 'growl'
-  gem.add_development_dependency 'guard'
-  gem.add_development_dependency 'guard-bundler'
-  gem.add_development_dependency 'guard-rspec'
   gem.add_development_dependency 'simplecov'
   gem.add_development_dependency 'rack-test'
   gem.add_development_dependency 'rake'
-  gem.add_development_dependency 'rb-fsevent'
   gem.add_development_dependency 'rdiscount'
   gem.add_development_dependency 'rspec', '~> 2.8'
   gem.add_development_dependency 'yard'

spec/omniauth/failure_endpoint_spec.rb

@@ -0,0 +1,45 @@
+require 'spec_helper'
+
+describe OmniAuth::FailureEndpoint do
+  subject{ OmniAuth::FailureEndpoint }
+
+  context 'development' do
+    before do 
+      @rack_env = ENV['RACK_ENV']
+      ENV['RACK_ENV'] = 'development'
+    end
+
+    it 'should raise out the error' do
+      err = StandardError.new("Blah")
+      expect{ subject.call('omniauth.error' => err) }.to raise_error(err)
+    end
+
+    it 'should raise out an OmniAuth::Error if no omniauth.error is set' do
+      expect{ subject.call('omniauth.error.type' => 'example') }.to raise_error(OmniAuth::Error, "example")
+    end
+
+    after do
+      ENV['RACK_ENV'] = @rack_env
+    end
+  end
+
+  context 'non-development' do
+    let(:env){ {'omniauth.error.type' => 'invalid_request'} }
+    
+    it 'should be a redirect' do
+      status, head, body = *subject.call(env)
+      status.should == 302
+    end
+
+    it 'should include the SCRIPT_NAME' do
+      status, head, body = *subject.call(env.merge('SCRIPT_NAME' => '/random'))
+      head['Location'].should == '/random/auth/failure?message=invalid_request'
+    end
+
+    it 'should respect configured path prefix' do
+      OmniAuth.config.stub(:path_prefix => '/boo')
+      status, head, body = *subject.call(env)
+      head["Location"].should == '/boo/failure?message=invalid_request'
+    end
+  end
+end

spec/omniauth/strategy_spec.rb

@@ -509,7 +509,7 @@ describe OmniAuth::Strategy do
       end
 
       it 'should be case insensitive on callback path' do
-        strategy.call(make_env('/AUTH/TeSt/CaLlBAck')).should == strategy.call(make_env('/auth/test/callback'))
+        strategy.call(make_env('/AUTH/TeSt/CaLlBAck')).first.should == strategy.call(make_env('/auth/test/callback')).first
       end
 
       it 'should maintain query string parameters' do