Mockups for unique foreign keys

mockups/base.py

@@ -100,7 +100,8 @@ def __init__(self, model, constraints=None, follow_fk=None,
 
             ``generate_fk``: A boolean which indicates if related models should
             also be created with random values. The *follow_fk* parameter will
-            be ignored if *generate_fk* is set to ``True``.
+            be ignored if *generate_fk* is set to ``True`` or foreign field is
+            unique.
 
             ``follow_m2m``: A tuple containing minium and maximum of model
             instances that are assigned to ``ManyToManyField``. No new

mockups/generators.py

@@ -526,7 +526,8 @@ def get_generator(self, field, *args, **kwargs):
 class ForeignKeyFieldGenerator(FieldGenerator):
     def get_generator(self, field, generate_fk=None, follow_fk=None, **kwargs):
         # if generate_fk is set, follow_fk is ignored.
-        if field.name in generate_fk:
+        # also generate fk if field is unique to ensure uniqueness.
+        if field.name in generate_fk or self.field.unique:
             mockup = get_mockup(
                 field.rel.to,
                 follow_fk=follow_fk.get_deep_links(field.name),

mockups/tests/mockups_test/tests.py

@@ -145,15 +145,15 @@ def test_follow_only_some_foreignkeys(self):
                 self.assertEqual(obj.related, related)
                 self.assertEqual(obj.limitedfk, None)
 
-    def test_follow_fk_for_o2o(self):
+    def test_unique_fk_for_o2o(self):
         # OneToOneField is the same as a ForeignKey with unique=True
-        filler = Mockup(O2OModel, follow_fk=True)
+        filler = Mockup(O2OModel)
 
-        simple = SimpleModel.objects.create()
-        obj = filler.create()[0]
-        self.assertEqual(obj.o2o, simple)
+        all_o2o = set()
+        for obj in filler.create(10):
+            all_o2o.add(obj.o2o)
 
-        self.assertRaises(CreateInstanceError, filler.create)
+        self.assertEqual(set(SimpleModel.objects.all()), all_o2o)
 
     def test_generate_fk_for_o2o(self):
         # OneToOneField is the same as a ForeignKey with unique=True