Changeset 7574 for django/trunk/tests/regressiontests/many_to_one_regress

Timestamp:

06/04/08 19:39:32 (6 months ago)

Author:

jacob

Message:

Fixed #6886: Tightened up ForeignKey? and OneToOne? field assignment. Specifically:

• Raise a ValueError? if you try to assign the wrong type of object.
  
• Raise a ValueError? if you try to assign None to a field not specified with null=True.
  
• Cache the set value at set time instead of just at lookup time.
  

This is a slightly backwards-incompatible change; see BackwardsIncompatibleChanges for more details.

Files:

• django/trunk/tests/regressiontests/many_to_one_regress/models.py (modified) (2 diffs)

django/trunk/tests/regressiontests/many_to_one_regress/models.py

@@ +1 @@
+"""
+Regression tests for a few FK bugs: #1578, #6886
+"""
+
-from django.db import models
-
@@ -26 +30 @@
-
-__test__ = {'API_TESTS':"""
-AddManipulator().save(dict(id='3', name='An example', another=None)) 
+objects.create(id='3', name='An example')
-<Third: Third object>
->>> parent = Parent(name = 'fred')
->>> parent.save()
-AddManipulator().save(dict(name='bam-bam', parent=parent.id)
+objects.create(name='bam-bam', parent=parent
-<Child: Child object>
+
+#
+# Tests of ForeignKey assignment and the related-object cache (see #6886)
+#
+>>> p = Parent.objects.create(name="Parent")
+>>> c = Child.objects.create(name="Child", parent=p)
+
+# Look up the object again so that we get a "fresh" object
+>>> c = Child.objects.get(name="Child")
+>>> p = c.parent
+
+# Accessing the related object again returns the exactly same object
+>>> c.parent is p
+True
+
+# But if we kill the cache, we get a new object
+>>> del c._parent_cache
+>>> c.parent is p
+False
+
+# Assigning a new object results in that object getting cached immediately
+>>> p2 = Parent.objects.create(name="Parent 2")
+>>> c.parent = p2
+>>> c.parent is p2
+True
+
+# Assigning None fails: Child.parent is null=False
+>>> c.parent = None
+Traceback (most recent call last):
+    ...
+ValueError: Cannot assign None: "Child.parent" does not allow null values.
+
+# You also can't assign an object of the wrong type here
+>>> c.parent = First(id=1, second=1)
+Traceback (most recent call last):
+    ...
+ValueError: Cannot assign "<First: First object>": "Child.parent" must be a "Parent" instance.
+
-"""}