refactor #read_ and #write_attribute to behave the same when called with a missing property

lib/couchrest/model/properties.rb

@@ -23,12 +23,12 @@ module CouchRest
       end
 
       def read_attribute(property)
-        self[property.to_s]
+        prop = find_property!(property)
+        self[prop.to_s]
       end
 
       def write_attribute(property, value)
-        prop = property.is_a?(Property) ? property : self.class.properties.detect {|p| p.to_s == property.to_s}
-        raise "Missing property definition for #{property.to_s}" unless prop
+        prop = find_property!(property)
         self[prop.to_s] = prop.cast(self, value)
       end
 
@@ -40,6 +40,13 @@ module CouchRest
         end
       end
 
+      private
+      def find_property!(property)
+        prop = property.is_a?(Property) ? property : self.class.properties.detect {|p| p.to_s == property.to_s}
+        raise ArgumentError, "Missing property definition for #{property.to_s}" unless prop
+        prop
+      end
+
       module ClassMethods
 
         def property(name, *options, &block)

spec/couchrest/property_spec.rb

@@ -59,42 +59,54 @@ describe "Model properties" do
     @card.updated_at.should_not be_nil
   end
 
-  it "should let you use read_attribute method" do
-    @card.last_name = "Aimonetti"
-    @card.read_attribute(:last_name).should eql('Aimonetti')
-    @card.read_attribute('last_name').should eql('Aimonetti')
-    last_name_prop = @card.properties.find{|p| p.name == 'last_name'}
-    @card.read_attribute(last_name_prop).should eql('Aimonetti')
+  describe '#read_attribute' do
+    it "should let you use read_attribute method" do
+      @card.last_name = "Aimonetti"
+      @card.read_attribute(:last_name).should eql('Aimonetti')
+      @card.read_attribute('last_name').should eql('Aimonetti')
+      last_name_prop = @card.properties.find{|p| p.name == 'last_name'}
+      @card.read_attribute(last_name_prop).should eql('Aimonetti')
+    end
+
+    it 'should raise an error if the property does not exist' do
+      expect { @card.read_attribute(:this_property_should_not_exist) }.to raise_error(ArgumentError)
+    end
   end
 
-  it "should let you use write_attribute method" do
-    @card.write_attribute(:last_name, 'Aimonetti 1')
-    @card.last_name.should eql('Aimonetti 1')
-    @card.write_attribute('last_name', 'Aimonetti 2')
-    @card.last_name.should eql('Aimonetti 2')
-    last_name_prop = @card.properties.find{|p| p.name == 'last_name'}
-    @card.write_attribute(last_name_prop, 'Aimonetti 3')
-    @card.last_name.should eql('Aimonetti 3')
-  end
+  describe '#write_attribute' do
+    it "should let you use write_attribute method" do
+      @card.write_attribute(:last_name, 'Aimonetti 1')
+      @card.last_name.should eql('Aimonetti 1')
+      @card.write_attribute('last_name', 'Aimonetti 2')
+      @card.last_name.should eql('Aimonetti 2')
+      last_name_prop = @card.properties.find{|p| p.name == 'last_name'}
+      @card.write_attribute(last_name_prop, 'Aimonetti 3')
+      @card.last_name.should eql('Aimonetti 3')
+    end
 
-  it "should let you use write_attribute on readonly properties" do
-    lambda {
-      @card.read_only_value = "foo"
-    }.should raise_error
-    @card.write_attribute(:read_only_value, "foo")
-    @card.read_only_value.should == 'foo'
-  end
+    it 'should raise an error if the property does not exist' do
+      expect { @card.write_attribute(:this_property_should_not_exist, 823) }.to raise_error(ArgumentError)
+    end
 
-  it "should cast via write_attribute" do
-    @card.write_attribute(:cast_alias, {:name => ["Sam", "Lown"]})
-    @card.cast_alias.class.should eql(Person)
-    @card.cast_alias.name.last.should eql("Lown")
-  end
+    it "should let you use write_attribute on readonly properties" do
+      lambda {
+        @card.read_only_value = "foo"
+      }.should raise_error
+      @card.write_attribute(:read_only_value, "foo")
+      @card.read_only_value.should == 'foo'
+    end
 
-  it "should not cast via write_attribute if property not casted" do
-    @card.write_attribute(:first_name, {:name => "Sam"})
-    @card.first_name.class.should eql(Hash)
-    @card.first_name[:name].should eql("Sam")
+    it "should cast via write_attribute" do
+      @card.write_attribute(:cast_alias, {:name => ["Sam", "Lown"]})
+      @card.cast_alias.class.should eql(Person)
+      @card.cast_alias.name.last.should eql("Lown")
+    end
+
+    it "should not cast via write_attribute if property not casted" do
+      @card.write_attribute(:first_name, {:name => "Sam"})
+      @card.first_name.class.should eql(Hash)
+      @card.first_name[:name].should eql("Sam")
+    end
   end