Missing key raises now KeyError, not ArgumentError

lib/twitter/creator.rb

@@ -2,13 +2,9 @@ module Twitter
   class Creator
 
     def self.new(method, klass, attrs={})
-      type = attrs.delete(method.to_sym)
-      if type
-        const_name = type.gsub(/\/(.?)/){"::#{$1.upcase}"}.gsub(/(?:^|_)(.)/){$1.upcase}
-        klass.const_get(const_name.to_sym).new(attrs)
-      else
-        raise ArgumentError, "argument must have :#{method} key"
-      end
+      type = attrs.fetch(method.to_sym)
+      const_name = type.gsub(/\/(.?)/){"::#{$1.upcase}"}.gsub(/(?:^|_)(.)/){$1.upcase}
+      klass.const_get(const_name.to_sym).new(attrs)
     end
 
   end

lib/twitter/identity.rb

@@ -12,8 +12,8 @@ class Identity < Twitter::Base
     # @raise [ArgumentError] Error raised when supplied argument is missing an :id key.
     # @return [Twitter::Identity]
     def initialize(attrs={})
+      attrs.fetch(:id)
       super
-      raise ArgumentError, "argument must have an :id key" unless id
     end
 
   end

spec/twitter/geo_creator_spec.rb

@@ -11,8 +11,8 @@
       geo = Twitter::GeoCreator.new(:type => "Polygon")
       expect(geo).to be_a Twitter::Geo::Polygon
     end
-    it "raises an ArgumentError when type is not specified" do
-      expect{Twitter::GeoCreator.new}.to raise_error ArgumentError
+    it "raises a KeyError when type is not specified" do
+      expect{Twitter::GeoCreator.new}.to raise_error KeyError
     end
   end
 

spec/twitter/identifiable_spec.rb

@@ -3,8 +3,8 @@
 describe Twitter::Identity do
 
   describe "#initialize" do
-    it "raises an ArgumentError when type is not specified" do
-      expect{Twitter::Identity.new}.to raise_error ArgumentError
+    it "raises a KeyError when id is not specified" do
+      expect{Twitter::Identity.new}.to raise_error KeyError
     end
   end
 

spec/twitter/media_creator_spec.rb

@@ -7,8 +7,8 @@
       media = Twitter::MediaCreator.new(:id => 1, :type => "photo")
       expect(media).to be_a Twitter::Media::Photo
     end
-    it "raises an ArgumentError when type is not specified" do
-      expect{Twitter::MediaCreator.new}.to raise_error ArgumentError
+    it "raises a KeyError when type is not specified" do
+      expect{Twitter::MediaCreator.new}.to raise_error KeyError
     end
   end