Adding error handling to dispatchers.

lib/twitter_auth.rb

@@ -67,3 +67,7 @@ def self.net
 require 'twitter_auth/controller_extensions'
 require 'twitter_auth/cryptify'
 require 'twitter_auth/dispatcher/oauth'
+require 'twitter_auth/dispatcher/basic'
+require 'twitter_auth/dispatcher/shared'
+
+class TwitterAuth::Dispatcher::Error < StandardError; end

lib/twitter_auth/dispatcher/basic.rb

@@ -3,6 +3,8 @@
 module TwitterAuth
   module Dispatcher
     class Basic
+      include TwitterAuth::Dispatcher::Shared
+
       attr_accessor :user
 
       def initialize(user)
@@ -20,9 +22,7 @@ def request(http_method, path, body=nil, *arguments)
           http.request(req)
         }
 
-        JSON.parse(response.body)
-      rescue JSON::ParserError
-        response.body
+        handle_response(response)      
       end
 
       def get(path, *arguments)

lib/twitter_auth/dispatcher/oauth.rb

@@ -3,6 +3,8 @@
 module TwitterAuth
   module Dispatcher
     class Oauth < OAuth::AccessToken
+      include TwitterAuth::Dispatcher::Shared
+
       attr_accessor :user
 
       def initialize(user)
@@ -14,9 +16,8 @@ def initialize(user)
       def request(http_method, path, *arguments)
         path << '.json' unless path.match(/\.(:?xml|json)\z/i)
         response = super
-        JSON.parse(response.body)
-      rescue JSON::ParserError
-        response.body
+
+        handle_response(response)
       end
     end
   end

lib/twitter_auth/dispatcher/shared.rb

@@ -0,0 +1,28 @@
+module TwitterAuth
+  module Dispatcher
+    module Shared
+      def handle_response(response)
+        case response
+        when Net::HTTPOK 
+          begin
+            JSON.parse(response.body)
+          rescue JSON::ParserError
+            response.body
+          end
+        else
+          message = begin
+            JSON.parse(response.body)['error']
+          rescue JSON::ParserError
+            if match = response.body.match(/<error>(.*)<\/error>/)
+              match[1]
+            else
+              'An error occurred processing your Twitter request.'
+            end
+          end
+
+          raise TwitterAuth::Dispatcher::Error, message
+        end
+      end
+    end
+  end
+end

spec/twitter_auth/dispatcher/basic_spec.rb

@@ -47,6 +47,21 @@
       @net.should_receive(:start)
       lambda{@dispatcher.request(:get, '/fake')}.should raise_error(NoMethodError)
     end
+
+    it "should raise a TwitterAuth::Dispatcher::Error if response code isn't 200" do
+      FakeWeb.register_uri('https://twitter.com:443/bad_response.json', :string => {'error' => 'bad response'}.to_json, :status => ['401', 'Unauthorized'])
+      lambda{@dispatcher.request(:get, '/bad_response')}.should raise_error(TwitterAuth::Dispatcher::Error)
+    end
+
+    it 'should set the error message to the JSON message' do
+      FakeWeb.register_uri('https://twitter.com:443/bad_response.json', :string => {'error' => 'bad response'}.to_json, :status => ['401', 'Unauthorized'])
+      lambda{@dispatcher.request(:get, '/bad_response')}.should raise_error(TwitterAuth::Dispatcher::Error, 'bad response')
+    end
+
+    it 'should set the error message to the XML message' do
+      FakeWeb.register_uri('https://twitter.com:443/bad_response.xml', :string => "<hash>\n<request>/bad_response.xml</request>\n<error>bad response</error>\n</hash>", :status => ['401', 'Unauthorized'])
+      lambda{@dispatcher.request(:get, '/bad_response')}.should raise_error(TwitterAuth::Dispatcher::Error, 'bad response')
+    end
   end
 
   %w(get post delete put).each do |method|

spec/twitter_auth/dispatcher/oauth_spec.rb

@@ -45,6 +45,21 @@
       @dispatcher.request(:get, '/fake').should == @dispatcher.request(:get, '/fake.json')
     end
 
+    it "should raise a TwitterAuth::Dispatcher::Error if response code isn't 200" do
+      FakeWeb.register_uri('https://twitter.com:443/bad_response.json', :string => {'error' => 'bad response'}.to_json, :status => ['401', 'Unauthorized'])
+      lambda{@dispatcher.request(:get, '/bad_response')}.should raise_error(TwitterAuth::Dispatcher::Error)
+    end
+
+    it 'should set the error message to the JSON message' do
+      FakeWeb.register_uri('https://twitter.com:443/bad_response.json', :string => {'error' => 'bad response'}.to_json, :status => ['401', 'Unauthorized'])
+      lambda{@dispatcher.request(:get, '/bad_response')}.should raise_error(TwitterAuth::Dispatcher::Error, 'bad response')
+    end
+
+    it 'should set the error message to the XML message' do
+      FakeWeb.register_uri('https://twitter.com:443/bad_response.xml', :string => "<hash>\n<request>/bad_response.xml</request>\n<error>bad response</error>\n</hash>", :status => ['401', 'Unauthorized'])
+      lambda{@dispatcher.request(:get, '/bad_response')}.should raise_error(TwitterAuth::Dispatcher::Error, 'bad response')
+    end
+
     it 'should work with verb methods' do
       @dispatcher.get('/fake').should == @dispatcher.request(:get, '/fake')
     end