fixed dirty attributes when old value incorrectly read and added more examples for dirty attributes

CHANGELOG

@@ -1,3 +1,6 @@
+[2008-10-28]
+  - fixed bug when dirty attributes not reflecting change when attribute changed from time value to nil [reported by Brad (pvjq)]
+
 [2008-08-25]
   - fixed bug for non-timezone write method not updating changed attributes hash [reported by Sylvestre Mergulhão]
 

lib/validates_timeliness/attribute_methods.rb

@@ -71,8 +71,7 @@ module ValidatesTimeliness
     def write_date_time_attribute(attr_name, value)
       attr_name = attr_name.to_s
       column = column_for_attribute(attr_name)
-
+      old = read_attribute(attr_name) if defined?(ActiveRecord::Dirty)
-      old = read_attribute('#{attr_name}') if defined?(ActiveRecord::Dirty)
       new = self.class.parse_date_time(value, column.type)
 
       if self.class.send(:create_time_zone_conversion_attribute?, attr_name, column)

spec/attribute_methods_spec.rb

@@ -92,13 +92,45 @@ describe ValidatesTimeliness::AttributeMethods do
       @person.birth_date_and_time_changed?.should be_true
     end
     
-    it "should show changes for time attribute as nil to Time object" do
+    describe "dirty attributes" do
+    
+      it "should show changes when time attribute changed from nil to Time object" do
         time_string = "2000-01-01 02:03:04"
         @person.birth_date_and_time = time_string
         time = @person.birth_date_and_time
         @person.changes.should == {"birth_date_and_time" => [nil, time]}
       end
       
+      it "should show changes when time attribute changed from Time object to nil" do
+        time_string = "2020-01-01 02:03:04"
+        @person.birth_date_and_time = time_string
+        @person.save false
+        @person.reload
+        time = @person.birth_date_and_time
+        @person.birth_date_and_time = nil
+        @person.changes.should == {"birth_date_and_time" => [time, nil]}
+      end
+      
+      it "should show no changes when assigned same value as Time object" do
+        time_string = "2020-01-01 02:03:04"
+        @person.birth_date_and_time = time_string
+        @person.save false
+        @person.reload
+        time = @person.birth_date_and_time
+        @person.birth_date_and_time = time
+        @person.changes.should == {}
+      end
+      
+      it "should show no changes when assigned same value as time string" do
+        time_string = "2020-01-01 02:03:04"
+        @person.birth_date_and_time = time_string
+        @person.save false
+        @person.reload
+        @person.birth_date_and_time = time_string
+        @person.changes.should == {}
+      end
+      
+    end
   else
     
     it "should return time object from database in default timezone" do