diff --git a/scrapy/tests/test_newitem.py b/scrapy/tests/test_newitem.py
index 203fa332a..4d6278b88 100644
--- a/scrapy/tests/test_newitem.py
+++ b/scrapy/tests/test_newitem.py
@@ -3,6 +3,7 @@ import decimal
 import unittest
 
 from scrapy.contrib_exp.newitem import *
+from scrapy.contrib_exp.newitem.fields import BaseField
 
 
 class NewItemTest(unittest.TestCase):
@@ -25,8 +26,54 @@ class NewItemTest(unittest.TestCase):
         i.names = ['name1', 'name2']
         assert i.names == ['name1', 'name2']
 
+    def test_invalid_field(self):
+        class TestItem(Item):
+            pass
+
+        i = TestItem()
+        def set_invalid_field():
+            i.field = 'text'
+
+        self.assertRaises(AttributeError, set_invalid_field)
+
+        def get_invalid_field():
+            return i.field
+
+        self.assertRaises(AttributeError, get_invalid_field)
+
+    def test_default_value(self):
+        class TestItem(Item):
+            name = StringField(default='John')
+ 
+        i = TestItem()
+        assert i.name == 'John'
+
+    def test_topython_iter(self):
+        class TestItem(Item):
+            name = StringField()
+ 
+        i = TestItem()
+        i.name = ('John', 'Doe')
+        assert i.name == 'John Doe'
+
+    def test_repr(self):
+        class TestItem(Item):
+            name = StringField()
+
+        i = TestItem()
+        i.name = 'John Doe'
+        assert i.__repr__() == "TestItem({'name': 'John Doe'})"
+
 
 class NewItemFieldsTest(unittest.TestCase):
+    
+    def test_base_field(self):
+        f = BaseField()
+
+        assert f.default == None
+        assert f.assign(1) == 1
+        assert f.to_python(1) == 1
+
     def test_boolean_field(self):
         class TestItem(Item):
             field = BooleanField()
@@ -35,11 +82,13 @@ class NewItemFieldsTest(unittest.TestCase):
 
         i.field = True
         assert i.field == True
+    
         i.field = 1
         assert i.field == True
 
         i.field = False
         assert i.field == False
+
         i.field = 0
         assert i.field == False
 
@@ -49,13 +98,27 @@ class NewItemFieldsTest(unittest.TestCase):
 
         i = TestItem()
 
-        today = datetime.date.today()
-        i.field = today
-        assert i.field == today
+        d_today = datetime.date.today()
+        i.field = d_today
+        assert i.field == d_today
+
+        dt_today = datetime.datetime.today()
+        i.field = dt_today
+        assert i.field == dt_today.date()
  
         i.field = '2009-05-21'
         assert i.field == datetime.date(2009, 5, 21)
 
+        def set_invalid_format():
+            i.field = '21-05-2009'
+
+        self.assertRaises(ValueError, set_invalid_format)
+
+        def set_invalid_date():
+            i.field = '2009-05-51'
+
+        self.assertRaises(ValueError, set_invalid_date)
+
     def test_datetime_field(self):
         class TestItem(Item):
             field = DateTimeField()
@@ -70,6 +133,9 @@ class NewItemFieldsTest(unittest.TestCase):
         i.field = d_today
         assert i.field == datetime.datetime(d_today.year, d_today.month,
                                             d_today.day)
+
+        i.field = '2009-05-21 11:08:10.100'
+        assert i.field == datetime.datetime(2009, 5, 21, 11, 8, 10, 100)
  
         i.field = '2009-05-21 11:08:10'
         assert i.field == datetime.datetime(2009, 5, 21, 11, 8, 10)
@@ -80,6 +146,21 @@ class NewItemFieldsTest(unittest.TestCase):
         i.field = '2009-05-21'
         assert i.field == datetime.datetime(2009, 5, 21)
 
+        def set_invalid_usecs():
+            i.field = '2009-05-21 11:08:10.usecs'
+
+        self.assertRaises(ValueError, set_invalid_usecs)
+
+        def set_invalid_format():
+            i.field = '21-05-2009'
+
+        self.assertRaises(ValueError, set_invalid_format)
+
+        def set_invalid_date():
+            i.field = '2009-05-51'
+
+        self.assertRaises(ValueError, set_invalid_date)
+
     def test_decimal_field(self):
         class TestItem(Item):
             field = DecimalField()
@@ -91,6 +172,11 @@ class NewItemFieldsTest(unittest.TestCase):
 
         i.field = '3.14'
         assert i.field == decimal.Decimal('3.14')
+        
+        def set_invalid_value():
+            i.field = 'text'
+
+        self.assertRaises(ValueError, set_invalid_value)
 
     def test_float_field(self):
         class TestItem(Item):
@@ -103,6 +189,11 @@ class NewItemFieldsTest(unittest.TestCase):
 
         i.field = '3.14'
         assert i.field == 3.14
+        
+        def set_invalid_value():
+            i.field = 'text'
+
+        self.assertRaises(ValueError, set_invalid_value)
 
     def test_integer_field(self):
         class TestItem(Item):
@@ -116,7 +207,12 @@ class NewItemFieldsTest(unittest.TestCase):
         i.field = '3'
         assert i.field == 3
 
-    def test_sting_field(self):
+        def set_invalid_value():
+            i.field = 'text'
+
+        self.assertRaises(ValueError, set_invalid_value)
+
+    def test_string_field(self):
         class TestItem(Item):
             field = StringField()
 
@@ -125,3 +221,8 @@ class NewItemFieldsTest(unittest.TestCase):
         i.field = 'hello'
         assert i.field == 'hello'
 
+        def set_invalid_value():
+            i.field = 3 
+
+        self.assertRaises(ValueError, set_invalid_value)
+