Automatically create nested R object rules if required

bridgekeeper/rule_r_tests.py

@@ -106,6 +106,36 @@ def test_nested_rule_object():
     assert shrubbery_nomatch not in qs
 
 
+def test_nested_one_to_many_rule_object():
+    user = UserFactory()
+
+    shrubbery_match = ShrubberyFactory(branch=user.profile.branch)
+    shrubbery_nomatch = ShrubberyFactory()
+    branch_profile_check_r = R(branch=R(profile=R(user=lambda user: user)))
+
+    assert branch_profile_check_r.check(user, shrubbery_match)
+    assert not branch_profile_check_r.check(user, shrubbery_nomatch)
+
+    qs = branch_profile_check_r.filter(user, Shrubbery.objects.all())
+    assert shrubbery_match in qs
+    assert shrubbery_nomatch not in qs
+
+
+def test_unnested_one_to_many_rule_object():
+    user = UserFactory()
+
+    shrubbery_match = ShrubberyFactory(branch=user.profile.branch)
+    shrubbery_nomatch = ShrubberyFactory()
+    branch_profile_check_r = R(branch__profile__user=lambda user: user)
+
+    assert branch_profile_check_r.check(user, shrubbery_match)
+    assert not branch_profile_check_r.check(user, shrubbery_nomatch)
+
+    qs = branch_profile_check_r.filter(user, Shrubbery.objects.all())
+    assert shrubbery_match in qs
+    assert shrubbery_nomatch not in qs
+
+
 def test_many_relation_to_user():
     s1 = StoreFactory()
     s2 = StoreFactory()

bridgekeeper/rules.py

@@ -320,7 +320,15 @@ def check(self, user, instance=None):
             # Find the appropriate LHS on this object, traversing
             # foreign keys if necessary.
             lhs = instance
-            for key_fragment in key.split("__"):
+            fragments = key.split("__")
+            for i, key_fragment in enumerate(fragments):
+                # Catch a many-to-many or many-to-one traversal and split it
+                # across multiple Rules
+                if not hasattr(lhs.__class__, "_meta"):
+                    new_kwargs = {"__".join(fragments[i:]): value}
+                    value = R(**new_kwargs)
+                    break
+
                 field = lhs.__class__._meta.get_field(key_fragment,)
                 if isinstance(field, ForeignObjectRel):
                     attr = field.get_accessor_name()