Allow relation _id fields to use a sequence

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 - Validate `increment_by` parameter of `seq` helper when `value` is an instance of `datetime` [PR #247](https://github.com/model-bakers/model_bakery/pull/247)
 - Fix a simple typo in `bulk_create` disclaimer in docs
+- Allow relation `_id` fields to use sequences [PR #253](https://github.com/model-bakers/model_bakery/pull/253/)
 - Fix bulk_create not working with multi-database setup [PR #252](https://github.com/model-bakers/model_bakery/pull/252)
 - Conditionally support NullBooleanField, it's under deprecation and will be removed in Django 4.0 [PR #25](https://github.com/model-bakers/model_bakery/pull/250)
 - Fix Django max version pin in requirements file [PR #251](https://github.com/model-bakers/model_bakery/pull/251)

model_bakery/baker.py

@@ -363,10 +363,20 @@ def _make(
                         ]
                     else:
                         self.m2m_dict[field.name] = self.model_attrs.pop(field.name)
+            # is an _id relation that has a sequence defined
+            elif (
+                (isinstance(field, OneToOneField) or isinstance(field, ForeignKey))
+                and hasattr(field, "attname")
+                and field.attname in self.iterator_attrs
+            ):
+                self.model_attrs[field.attname] = next(
+                    self.iterator_attrs[field.attname]
+                )
             elif field.name not in self.model_attrs:
                 if (
                     not isinstance(field, ForeignKey)
-                    or "{0}_id".format(field.name) not in self.model_attrs
+                    or hasattr(field, "attname")
+                    and field.attname not in self.model_attrs
                 ):
                     self.model_attrs[field.name] = self.generate_value(
                         field, commit_related
@@ -476,6 +486,14 @@ def _skip_field(self, field: Field) -> bool:
         if isinstance(field, FileField) and not self.create_files:
             return True
 
+        # Don't Skip related _id fields defined in the iterator attributes
+        if (
+            (isinstance(field, OneToOneField) or isinstance(field, ForeignKey))
+            and hasattr(field, "attname")
+            and field.attname in self.iterator_attrs
+        ):
+            return False
+
         # Skip links to parent so parent is not created twice.
         if isinstance(field, OneToOneField) and self._remote_field(field).parent_link:
             return True

tests/test_recipes.py

@@ -17,7 +17,10 @@
     Dog,
     DummyBlankFieldsModel,
     DummyNumbersModel,
+    LonelyPerson,
     Person,
+    Profile,
+    User,
 )
 
 recipe_attrs = {
@@ -32,6 +35,8 @@
     "birth_time": now(),
 }
 person_recipe = Recipe(Person, **recipe_attrs)
+user_recipe = Recipe(User)
+lonely_person_recipe = Recipe(LonelyPerson)
 
 
 def test_import_seq_from_recipe():
@@ -450,6 +455,28 @@ def test_increment_for_strings_with_suffix(self):
         person = fred_person.make()
         assert person.email == "fred3@example.com"
 
+    def test_increment_for_fks(self):
+        from model_bakery.recipe import seq  # NoQA
+
+        profiles = baker.make(Profile, _quantity=3)
+        start_id = profiles[0].id
+        seq_user = user_recipe.extend(username="name", profile_id=seq(start_id))
+        user = seq_user.make()
+        assert user.profile_id == start_id + 1
+        user = seq_user.make()
+        assert user.profile_id == start_id + 2
+
+    def test_increment_for_one_to_one(self):
+        from model_bakery.recipe import seq  # NoQA
+
+        people = baker.make(Person, _quantity=3)
+        start_id = people[0].id
+        seq_lonely_person = lonely_person_recipe.extend(only_friend_id=seq(start_id))
+        person = seq_lonely_person.make()
+        assert person.only_friend_id == start_id + 1
+        user = seq_lonely_person.make()
+        assert user.only_friend_id == start_id + 2
+
     def test_increment_for_strings_with_bad_suffix(self):
         from model_bakery.recipe import seq  # NoQA