better api versioning

close #1

lib/fb_graph2.rb

@@ -2,8 +2,9 @@ require 'active_support/all'
 require 'rack/oauth2'
 
 module FbGraph2
-  cattr_accessor :api_version, :gem_version, :logger, :debugging, :_http_config_, :object_classes
+  cattr_accessor :root_url, :api_version, :gem_version, :logger, :debugging, :_http_config_, :object_classes
 
+  self.root_url = 'https://graph.facebook.com'
   self.api_version = 'v2.0'
   self.gem_version = File.read(File.join(__dir__, '../VERSION')).delete("\n\r")
   self.logger = Logger.new(STDOUT)
@@ -11,10 +12,6 @@ module FbGraph2
   self.object_classes = Array.new
 
   class << self
-    def root_url
-      File.join('https://graph.facebook.com', api_version)
-    end
-
     def debugging?
       !!self.debugging
     end

lib/fb_graph2/node.rb

@@ -18,13 +18,13 @@ module FbGraph2
       self
     end
 
-    def fetch(params = {})
+    def fetch(params = {}, options = {})
-      attributes = get params
+      attributes = get params, options
       self.class.new(attributes[:id], attributes).authenticate access_token
     end
 
-    def self.fetch(identifier, params = {})
+    def self.fetch(identifier, params = {}, options = {})
-      new(identifier).fetch params
+      new(identifier).fetch params, options
     end
 
     def edge(edge, params = {}, options = {})
@@ -85,7 +85,11 @@ module FbGraph2
 
     def build_endpoint(options = {})
       File.join [
-        File.join(FbGraph2.root_url, id.to_s),
+        File.join(
+          FbGraph2.root_url,
+          options[:api_version] || FbGraph2.api_version,
+          id.to_s
+        ),
         options[:edge],
         Util.as_identifier(options[:edge_scope])
       ].compact.collect(&:to_s)

spec/fb_graph2/node_spec.rb

@@ -4,6 +4,58 @@ describe FbGraph2::Node do
   let(:klass) { FbGraph2::Node }
   let(:instance) { klass.new 'identifier' }
 
+  describe 'API Versioning' do
+    before do
+      @original = FbGraph2.api_version
+    end
+
+    after do
+      FbGraph2.api_version = @original
+    end
+
+    describe 'via global setting' do
+      before do
+        FbGraph2.api_version = 'v2.x'
+      end
+
+      describe '#fetch' do
+        it 'should use api_version globally' do
+          expect do
+            instance.fetch
+          end.to request_to 'v2.x/identifier', :get, api_version_in_path: true
+        end
+      end
+
+      describe '#edge' do
+        it 'should use api_version globally' do
+          expect do
+            instance.edge :foo
+          end.to request_to 'v2.x/identifier/foo', :get, api_version_in_path: true
+        end
+      end
+    end
+
+    describe 'via per-call option' do
+      describe '#fetch' do
+        it 'should use api_version locally' do
+          expect do
+            instance.fetch nil, api_version: 'v2.y'
+          end.to request_to 'v2.y/identifier', :get, api_version_in_path: true
+          FbGraph2.api_version.should == @original
+        end
+      end
+
+      describe '#edge' do
+        it 'should use api_version locally' do
+          expect do
+            instance.edge :foo, {}, api_version: 'v2.y'
+          end.to request_to 'v2.y/identifier/foo', :get, api_version_in_path: true
+          FbGraph2.api_version.should == @original
+        end
+      end
+    end
+  end
+
   context 'class' do
     subject { klass }
     it { should_not respond_to :register_attributes }
@@ -14,7 +66,7 @@ describe FbGraph2::Node do
       it 'should call API' do
         expect do
           klass.fetch 'foo'
-        end.to request_to '/foo'
+        end.to request_to 'foo'
       end
     end
   end

spec/fb_graph2_spec.rb

@@ -7,7 +7,7 @@ describe FbGraph2 do
   context 'as default' do
     its(:logger) { should be_a Logger }
     its(:api_version) { should == 'v2.0' }
-    its(:root_url) { should == 'https://graph.facebook.com/v2.0' }
+    its(:root_url) { should == 'https://graph.facebook.com' }
     its(:object_classes) { should contain_exactly *FbGraph2::Node.subclasses }
     it { should_not be_debugging }
   end
@@ -19,7 +19,7 @@ describe FbGraph2 do
 
   describe '.api_version' do
     before { FbGraph2.api_version = 'v2.x' }
-    its(:root_url) { should == 'https://graph.facebook.com/v2.x' }
+    its(:api_version) { should == 'v2.x' }
   end
 
   describe '.http_client' do

spec/spec_helper/mock_graph.rb

@@ -4,7 +4,7 @@ module MockGraph
   def mock_graph(method, path, response_path, options = {})
     stub_request(
       method,
-      endpoint_for(path)
+      endpoint_for(path, options)
     ).with(
       request_for(method, options)
     ).to_return(
@@ -26,18 +26,21 @@ module MockGraph
     response_for(response_path)[:body].read
   end
 
-  def request_to(path, method = :get)
+  def request_to(path, method = :get, options = {})
     raise_error { |e|
       e.should be_instance_of WebMock::NetConnectNotAllowedError
       e.message.should include("Unregistered request: #{method.to_s.upcase}")
-      e.message.should include(endpoint_for path)
+      e.message.should include(endpoint_for path, options)
     }
   end
 
   private
 
-  def endpoint_for(path)
+  def endpoint_for(path, options = {})
-    File.join(FbGraph2.root_url, path)
+    api_version = unless options[:api_version_in_path]
+      options[:api_version] || FbGraph2.api_version
+    end
+    File.join FbGraph2.root_url, api_version.to_s, path
   end
 
   def request_for(method, options = {})