add safe fails for adding and removing not saved models to many to many rel, add tests for save_related

ormar/models/model.py

@@ -192,7 +192,7 @@ class Model(NewBaseModel):
         self.set_save_status(True)
         return self
 
-    async def save_related(self) -> int:
+    async def save_related(self) -> int:  # noqa: CCR001
         update_count = 0
         for related in self.extract_related_names():
             if self.Meta.model_fields[related].virtual or issubclass(

ormar/models/modelproxy.py

@@ -12,7 +12,7 @@ from typing import (
     Union,
 )
 
-from ormar.exceptions import RelationshipInstanceError
+from ormar.exceptions import ModelPersistenceError, RelationshipInstanceError
 
 try:
     import orjson as json
@@ -63,8 +63,14 @@ class ModelTableProxy:
                 target_field = cls.Meta.model_fields[field]
                 target_pkname = target_field.to.Meta.pkname
                 if isinstance(field_value, ormar.Model):
-                    model_dict[field] = getattr(field_value, target_pkname)
+                    pk_value = getattr(field_value, target_pkname)
-                elif field_value:
+                    if not pk_value:
+                        raise ModelPersistenceError(
+                            f"You cannot save {field_value.get_name()} "
+                            f"model without pk set!"
+                        )
+                    model_dict[field] = pk_value
+                elif field_value:  # nested dict
                     model_dict[field] = field_value.get(target_pkname)
                 else:
                     model_dict.pop(field, None)

ormar/relations/relation_proxy.py

@@ -1,7 +1,7 @@
 from typing import Any, TYPE_CHECKING
 
 import ormar
-from ormar.exceptions import RelationshipInstanceError
+from ormar.exceptions import NoMatch, RelationshipInstanceError
 from ormar.relations.querysetproxy import QuerysetProxy
 
 if TYPE_CHECKING:  # pragma no cover
@@ -54,6 +54,11 @@ class RelationProxy(list):
         return queryset
 
     async def remove(self, item: "Model") -> None:  # type: ignore
+        if item not in self:
+            raise NoMatch(
+                f"Object {self._owner.get_name()} has no "
+                f"{item.get_name()} with given primary key!"
+            )
         super().remove(item)
         rel_name = item.resolve_relation_name(item, self._owner)
         relation = item._orm._get(rel_name)

tests/test_many_to_many.py

@@ -6,7 +6,7 @@ import pytest
 import sqlalchemy
 
 import ormar
-from ormar.exceptions import RelationshipInstanceError
+from ormar.exceptions import ModelPersistenceError, NoMatch, RelationshipInstanceError
 from tests.settings import DATABASE_URL
 
 database = databases.Database(DATABASE_URL, force_rollback=True)
@@ -196,3 +196,27 @@ async def test_selecting_related_fail_without_saving(cleanup):
         post = Post(title="Hello, M2M", author=guido)
         with pytest.raises(RelationshipInstanceError):
             await post.categories.all()
+
+
+@pytest.mark.asyncio
+async def test_adding_unsaved_related(cleanup):
+    async with database:
+        guido = await Author.objects.create(first_name="Guido", last_name="Van Rossum")
+        post = await Post.objects.create(title="Hello, M2M", author=guido)
+        news = Category(name="News")
+        with pytest.raises(ModelPersistenceError):
+            await post.categories.add(news)
+
+        await news.save()
+        await post.categories.add(news)
+        assert len(await post.categories.all()) == 1
+
+
+@pytest.mark.asyncio
+async def test_removing_unsaved_related(cleanup):
+    async with database:
+        guido = await Author.objects.create(first_name="Guido", last_name="Van Rossum")
+        post = await Post.objects.create(title="Hello, M2M", author=guido)
+        news = Category(name="News")
+        with pytest.raises(NoMatch):
+            await post.categories.remove(news)