remove yajl as a dependency

lib/sawyer/agent.rb

@@ -10,10 +10,15 @@ class << self
     end
 
     def self.serializer
-      @serializer ||= begin
-        require 'yajl'
-        Serializer.new(Yajl)
-      end
+      @serializer ||= Serializer.any_json
+    end
+
+    def self.encode(data)
+      serializer.encode(data)
+    end
+
+    def self.decode(data)
+      serializer.decode(data)
     end
 
     # Agents handle making the requests, and passing responses to

lib/sawyer/serializer.rb

@@ -3,6 +3,34 @@
 
 module Sawyer
   class Serializer
+    def self.any_json
+      yajl || multi_json || json
+    end
+
+    def self.yajl
+      require 'yajl'
+      new(Yajl)
+    rescue LoadError
+    end
+
+    def self.json
+      require 'json'
+      new(JSON)
+    rescue LoadError
+    end
+
+    def self.multi_json
+      require 'multi_json'
+      new(MultiJson)
+    rescue LoadError
+    end
+
+    def self.message_pack
+      require 'msgpack'
+      new(MessagePack, :pack, :unpack)
+    rescue LoadError
+    end
+
     # Public: Wraps a serialization format for Sawyer.  Nested objects are
     # prepared for serialization (such as changing Times to ISO 8601 Strings).
     # Any serialization format that responds to #dump and #load will work.
@@ -28,6 +56,7 @@ def encode(data)
     #
     # Returns a decoded Object.
     def decode(data)
+      return nil if data.nil? || data.empty?
       decode_object(@load.call(data))
     end
 

sawyer.gemspec

@@ -37,7 +37,6 @@ Gem::Specification.new do |s|
   ## that are needed for an end user to actually USE your code.
   s.add_dependency('faraday',      ['~> 0.8.4'])
   s.add_dependency('uri_template', ['~> 0.5.0'])
-  s.add_dependency('yajl-ruby',    ['~> 1.1.0'])
 
   ## List your development dependencies here. Development dependencies are
   ## those that are only needed during development

test/agent_test.rb

@@ -14,7 +14,7 @@ def test_accesses_root_relations
       @stubs.get '/a/' do |env|
         assert_equal 'foo.com', env[:url].host
 
-        [200, {}, Yajl.dump(
+        [200, {}, Sawyer::Agent.encode(
           :_links => {
             :users => {:href => '/users'}})]
       end
@@ -38,7 +38,7 @@ def test_starts_a_session
       @stubs.get '/a/' do |env|
         assert_equal 'foo.com', env[:url].host
 
-        [200, {}, Yajl.dump(
+        [200, {}, Sawyer::Agent.encode(
           :_links => {
             :users => {:href => '/users'}})]
       end

test/response_test.rb

@@ -9,7 +9,7 @@ def setup
         conn.builder.handlers.delete(Faraday::Adapter::NetHttp)
         conn.adapter :test, @stubs do |stub|
           stub.get '/' do
-            [200, {'Content-Type' => 'application/json'}, Yajl.dump(
+            [200, {'Content-Type' => 'application/json'}, Sawyer::Agent.encode(
               :a => 1,
               :_links => {
                 :self => {:href => '/a', :method => 'POST'}