Refactor Twitter::RateLimit class to be non-global

The global data being overwritten when there were multiple clients
running in parallel. Now, each client has its own Twitter::RateLimit
instance, as does each Twitter::Error object.

Closes #289.

README.md

@@ -162,7 +162,7 @@ Here are some fun facts about the 3.0 release:
 
 * The entire library is implemented in just 2,254 lines of code
 * With over 5,000 lines of specs, the spec-to-code ratio is well over 2:1
-* The spec suite contains 653 examples and runs in under 2 seconds on a MacBook
+* The spec suite contains 658 examples and runs in under 2 seconds on a MacBook
 * This project has 100% C0 code coverage (the tests execute every line of
   source code at least once)
 * At the time of release, this library is comprehensive: you can request all

lib/twitter.rb

@@ -10,9 +10,14 @@ class << self
     #
     # @return [Twitter::Client]
     def client
-      Twitter::Client.new(options)
+      if @client && @client.options == self.options
+        @client
+      else
+        @client = Twitter::Client.new(options)
+      end
     end
 
+    # @return [Hash]
     def options
       @options = {}
       Twitter::Configurable.keys.each do |key|

lib/twitter/base.rb

@@ -1,7 +1,6 @@
 module Twitter
   class Base
     attr_reader :attrs
-    alias body attrs
     alias to_hash attrs
 
     # Define methods that retrieve the value from an initialized instance variable Hash, using the attribute as a key
@@ -74,7 +73,7 @@ def self.fetch_or_new(attrs={})
     # @param attrs [Hash]
     # @return [Twitter::Base]
     def initialize(attrs={})
-      self.update(attrs)
+      @attrs = attrs
     end
 
     # Fetches an attribute of an object using hash notation
@@ -91,7 +90,6 @@ def [](method)
     # @param attrs [Hash]
     # @return [Twitter::Base]
     def update(attrs)
-      @attrs ||= {}
       @attrs.update(attrs)
       self
     end

lib/twitter/client.rb

@@ -15,6 +15,7 @@
 require 'twitter/metadata'
 require 'twitter/oembed'
 require 'twitter/place'
+require 'twitter/rate_limit'
 require 'twitter/rate_limit_status'
 require 'twitter/relationship'
 require 'twitter/saved_search'
@@ -35,6 +36,7 @@ module Twitter
   # @see http://dev.twitter.com/pages/every_developer
   class Client
     include Twitter::Configurable
+    attr_reader :rate_limit
     MAX_USERS_PER_REQUEST = 100
     METHOD_RATE_LIMITED = {
       :accept => false,
@@ -173,6 +175,16 @@ def initialize(options={})
       Twitter::Configurable.keys.each do |key|
         instance_variable_set("@#{key}", options[key] || Twitter.options[key])
       end
+      @rate_limit = Twitter::RateLimit.new
+    end
+
+    # @return [Hash]
+    def options
+      @options = {}
+      Twitter::Configurable.keys.each do |key|
+        @options[key] = instance_variable_get("@#{key}")
+      end
+      @options
     end
 
     # Check whether a method is rate limited
@@ -2876,7 +2888,7 @@ def request(method, path, params, options)
         request_headers[:authorization] = authorization.to_s
       end
       connection.url_prefix = options[:endpoint] || @endpoint
-      connection.run_request(method.to_sym, path, nil, request_headers) do |request|
+      response = connection.run_request(method.to_sym, path, nil, request_headers) do |request|
         unless params.empty?
           case request.method
           when :post, :put
@@ -2887,6 +2899,8 @@ def request(method, path, params, options)
         end
         yield request if block_given?
       end.env
+      @rate_limit.update(response[:response_headers])
+      response
     rescue Faraday::Error::ClientError
       raise Twitter::Error::ClientError
     end

lib/twitter/cursor.rb

@@ -19,9 +19,9 @@ def self.from_response(response={}, method=:ids, klass=nil)
     # Initializes a new Cursor
     #
     # @param attrs [Hash]
-    # @return [Twitter::Base]
+    # @return [Twitter::Cursor]
     def initialize(attrs={}, method=:ids, klass=nil)
-      self.update(attrs)
+      @attrs = attrs
       @collection = Array(attrs[method.to_sym]).map do |item|
         if klass
           klass.fetch_or_new(item)
@@ -56,15 +56,5 @@ def last?
     end
     alias last last?
 
-    # Update the attributes of an object
-    #
-    # @param attrs [Hash]
-    # @return [Twitter::Cursor]
-    def update(attrs)
-      @attrs ||= {}
-      @attrs.update(attrs)
-      self
-    end
-
   end
 end

lib/twitter/default.rb

@@ -5,7 +5,6 @@
 require 'twitter/response/parse_json'
 require 'twitter/response/raise_client_error'
 require 'twitter/response/raise_server_error'
-require 'twitter/response/rate_limit'
 require 'twitter/version'
 
 module Twitter
@@ -58,7 +57,6 @@ def middleware
             builder.use Twitter::Response::RaiseClientError # Handle 4xx server responses
             builder.use Twitter::Response::ParseJson        # Parse JSON response bodies using MultiJson
             builder.use Twitter::Response::RaiseServerError # Handle 5xx server responses
-            builder.use Twitter::Response::RateLimit        # Update RateLimit object
             builder.adapter Faraday.default_adapter         # Set Faraday's HTTP adapter
           end
         )

lib/twitter/error.rb

@@ -1,7 +1,7 @@
 module Twitter
   # Custom error class for rescuing from all Twitter errors
   class Error < StandardError
-    attr_reader :wrapped_exception
+    attr_reader :rate_limit, :wrapped_exception
 
     def self.errors
       @errors ||= Hash[descendants.map{|klass| [klass.const_get(:HTTP_STATUS_CODE), klass]}]
@@ -15,7 +15,8 @@ def self.descendants
     #
     # @param exception [Exception, String]
     # @return [Twitter::Error]
-    def initialize(exception=$!)
+    def initialize(exception=$!, response_headers={})
+      @rate_limit = Twitter::RateLimit.new(response_headers)
       if exception.respond_to?(:backtrace)
         super(exception.message)
         @wrapped_exception = exception

lib/twitter/error/client_error.rb

@@ -9,8 +9,8 @@ class ClientError < Twitter::Error
       #
       # @param body [Hash]
       # @return [Twitter::Error]
-      def self.from_response_body(body)
-        new(parse_error(body))
+      def self.from_response(response={})
+        new(parse_error(response[:body]), response[:response_headers])
       end
 
     private

lib/twitter/error/server_error.rb

@@ -6,12 +6,20 @@ class Error
     class ServerError < Twitter::Error
       MESSAGE = "Server Error"
 
+      # Create a new error from an HTTP environment
+      #
+      # @param body [Hash]
+      # @return [Twitter::Error]
+      def self.from_response(response={})
+        new(nil, response[:response_headers])
+      end
+
       # Initializes a new ServerError object
       #
       # @param message [String]
       # @return [Twitter::Error::ServerError]
-      def initialize(message=nil)
-        super(message || self.class.const_get(:MESSAGE))
+      def initialize(message=nil, response_headers={})
+        super((message || self.class.const_get(:MESSAGE)), response_headers)
       end
 
     end

lib/twitter/identity.rb

@@ -19,7 +19,7 @@ def self.fetch(attrs)
     # Stores an object in the identity map.
     #
     # @param attrs [Hash]
-    # @return [Twitter::Base]
+    # @return [Twitter::Identity]
     def self.store(object)
       Twitter.identity_map[self] ||= {}
       object.id && Twitter.identity_map[self][object.id] = object || super(object)
@@ -29,9 +29,9 @@ def self.store(object)
     #
     # @param attrs [Hash]
     # @raise [ArgumentError] Error raised when supplied argument is missing an :id key.
-    # @return [Twitter::Base]
+    # @return [Twitter::Identity]
     def initialize(attrs={})
-      self.update(attrs)
+      super
       raise ArgumentError, "argument must have an :id key" unless self.id
     end
 

lib/twitter/rate_limit.rb

@@ -1,47 +1,45 @@
-require 'singleton'
-
 module Twitter
   class RateLimit
-    include Singleton
-    attr_accessor :response_headers
-    alias headers response_headers
+    attr_reader :attrs
+    alias to_hash attrs
+
+    # @deprecated This method exists to provide backwards compatibility to when
+    #   Twitter::RateLimit was a singleton. Safe to remove in version 4.
+    def self.instance
+      Twitter.rate_limit
+    end
 
-    def initialize
-      self.reset!
+    # @return [Twitter::RateLimit]
+    def initialize(attrs={})
+      @attrs = attrs
     end
 
     # @return [String]
     def class
-      @response_headers.values_at('x-ratelimit-class', 'X-RateLimit-Class').compact.first
+      @attrs.values_at('x-ratelimit-class', 'X-RateLimit-Class').compact.first
     end
 
     # @return [Integer]
     def limit
-      limit = @response_headers.values_at('x-ratelimit-limit', 'X-RateLimit-Limit').compact.first
+      limit = @attrs.values_at('x-ratelimit-limit', 'X-RateLimit-Limit').compact.first
       limit.to_i if limit
     end
 
     # @return [Integer]
     def remaining
-      remaining = @response_headers.values_at('x-ratelimit-remaining', 'X-RateLimit-Remaining').compact.first
+      remaining = @attrs.values_at('x-ratelimit-remaining', 'X-RateLimit-Remaining').compact.first
       remaining.to_i if remaining
     end
 
-    # @return [Twitter::RateLimit]
-    def reset!
-      @response_headers = {}
-      self
-    end
-
     # @return [Time]
     def reset_at
-      reset = @response_headers.values_at('x-ratelimit-reset', 'X-RateLimit-Reset').compact.first
+      reset = @attrs.values_at('x-ratelimit-reset', 'X-RateLimit-Reset').compact.first
       Time.at(reset.to_i) if reset
     end
 
     # @return [Integer]
     def reset_in
-      if retry_after = @response_headers.values_at('retry-after', 'Retry-After').compact.first
+      if retry_after = @attrs.values_at('retry-after', 'Retry-After').compact.first
         retry_after.to_i
       elsif reset_at
         [(reset_at - Time.now).ceil, 0].max
@@ -51,10 +49,10 @@ def reset_in
 
     # Update the attributes of a Relationship
     #
-    # @param response_headers [Hash]
+    # @param attrs [Hash]
     # @return [Twitter::RateLimit]
-    def update(response_headers)
-      @response_headers.update(response_headers)
+    def update(attrs)
+      @attrs.update(attrs)
       self
     end
 

lib/twitter/relationship.rb

@@ -5,6 +5,14 @@
 module Twitter
   class Relationship < Twitter::Base
 
+    # Initializes a new object
+    #
+    # @param attrs [Hash]
+    # @return [Twitter::Relationship]
+    def initialize(attrs={})
+      @attrs = attrs[:relationship]
+    end
+
     # @return [Twitter::User]
     def source
       @source ||= Twitter::SourceUser.fetch_or_new(@attrs[:source]) unless @attrs[:source].nil?
@@ -20,7 +28,6 @@ def target
     # @param attrs [Hash]
     # @return [Twitter::Relationship]
     def update(attrs)
-      @attrs ||= {}
       @attrs.update(attrs[:relationship]) unless attrs[:relationship].nil?
       self
     end

lib/twitter/response/raise_client_error.rb

@@ -13,7 +13,7 @@ class RaiseClientError < Faraday::Response::Middleware
       def on_complete(env)
         status_code = env[:status].to_i
         error_class = Twitter::Error::ClientError.errors[status_code]
-        raise error_class.from_response_body(env[:body]) if error_class
+        raise error_class.from_response(env) if error_class
       end
 
     end

lib/twitter/response/raise_server_error.rb

@@ -10,7 +10,7 @@ class RaiseServerError < Faraday::Response::Middleware
       def on_complete(env)
         status_code = env[:status].to_i
         error_class = Twitter::Error::ServerError.errors[status_code]
-        raise error_class.new if error_class
+        raise error_class.from_response(env) if error_class
       end
 
     end

spec/twitter/client_spec.rb

@@ -83,6 +83,14 @@
     client2.verify_credentials.screen_name.should eq 'pengwynn'
   end
 
+  describe "#initalize" do
+    it "returns a different rate limit object for a new client" do
+      client1 = Twitter::Client.new
+      client2 = Twitter::Client.new
+      client1.rate_limit.should_not eq client2.rate_limit
+    end
+  end
+
   describe "#rate_limited?" do
     before do
       @client = Twitter::Client.new