Restructure where the CRUD base class lives for clarity and to avoid circular deps

src/infra/__init__.py

@@ -1,4 +1,4 @@
-from .db import Base, CRUD, CRUDRepo, UpdateMissingEntryError, get_database
+from .db import Base, CRUDRepoImpl, UpdateMissingEntryError, get_database
 from .users import UserModel, UserRepoImpl
 from .publication import (
     PublicationEntryModel,
@@ -11,7 +11,6 @@ from .subscription import SubscriptionModel, SubscriptionRepoImpl
 
 __all__ = [
     'Base',
-    'CRUD',
     'CRUDRepo',
     'UpdateMissingEntryError',
     'get_database',

src/infra/db.py

@@ -1,8 +1,8 @@
+from src.services.repo import CRUD
 from typing import Callable
 from sqlalchemy.orm import DeclarativeBase, Session
 from src.config.database import Database as DatabaseConfig
 from sqlalchemy import create_engine, Engine
-import abc
 
 
 class Base(DeclarativeBase):
@@ -22,25 +22,7 @@ class UpdateMissingEntryError(Exception):
         super().__init__(f'Attempted to update non-existing {model_name} {id}')
 
 
-class CRUD[T, C](abc.ABC):
+class CRUDRepoImpl[T: Base, U, C](CRUD[U, C]):
-    @abc.abstractmethod
-    def create(self, domain_item: C, verify: Callable[[T], None] | None) -> T:
-        pass
-
-    @abc.abstractmethod
-    def get(self, item_id: int) -> T | None:
-        pass
-
-    @abc.abstractmethod
-    def update(self, item_id: int, transform: Callable[[T], T]) -> T:
-        pass
-
-    @abc.abstractmethod
-    def delete(self, item_id: int, verify: Callable[[T], None] | None):
-        pass
-
-
-class CRUDRepo[T: Base, U, C](CRUD[U, C]):
     def __init__(
         self,
         db: Engine,

src/infra/db_tests.py

@@ -1,12 +1,12 @@
 from sqlalchemy import Engine
 from typing import Callable
-from src.infra import CRUDRepo, Base
+from src.infra import CRUDRepoImpl, Base
 import pytest
 
 
 class CRUDRepoHelper[A: Base, B, C]:
     @pytest.fixture
-    def repo(self, db: Engine) -> CRUDRepo[A, B, C]:
+    def repo(self, db: Engine) -> CRUDRepoImpl[A, B, C]:
         import pdb
 
         pdb.set_trace()
@@ -17,7 +17,7 @@ class CRUDRepoHelper[A: Base, B, C]:
         raise NotImplementedError()
 
     @pytest.fixture
-    def item(self, repo: CRUDRepo[A, B, C], dto: C) -> B:
+    def item(self, repo: CRUDRepoImpl[A, B, C], dto: C) -> B:
         return repo.create(dto, None)
 
     @pytest.fixture
@@ -31,26 +31,28 @@ class CRUDRepoHelper[A: Base, B, C]:
     def test_create(self, item: B):
         assert item is not None
 
-    def test_create_returns_none_if_invalid(self, repo: CRUDRepo[A, B, C], dto: C):
+    def test_create_returns_none_if_invalid(self, repo: CRUDRepoImpl[A, B, C], dto: C):
         def always_invalid(*_args, **_kw):
             raise ValueError('test')
 
         with pytest.raises(ValueError):
             repo.create(dto, always_invalid)
 
-    def test_create_returns_a_value_if_valid(self, repo: CRUDRepo[A, B, C], dto: C):
+    def test_create_returns_a_value_if_valid(self, repo: CRUDRepoImpl[A, B, C], dto: C):
         assert repo.create(dto, lambda _: None) is not None
 
-    def test_get_returns_none_when_missing(self, repo: CRUDRepo[A, B, C]):
+    def test_get_returns_none_when_missing(self, repo: CRUDRepoImpl[A, B, C]):
         assert repo.get(42) is None
 
-    def test_get_returns_a_value_if_it_exists(self, repo: CRUDRepo[A, B, C], item: B):
+    def test_get_returns_a_value_if_it_exists(self, repo: CRUDRepoImpl[A, B, C], item: B):
         assert repo.get(1) == item
 
-    def test_update(self, repo: CRUDRepo[A, B, C], transform: Callable[[B], B], item: B, expected_transformed_value: B):
+    def test_update(
+        self, repo: CRUDRepoImpl[A, B, C], transform: Callable[[B], B], item: B, expected_transformed_value: B
+    ):
         assert repo.update(1, transform) == expected_transformed_value
 
-    def test_delete(self, repo: CRUDRepo[A, B, C], item: B):
+    def test_delete(self, repo: CRUDRepoImpl[A, B, C], item: B):
         assert repo.get(1) is not None
         repo.delete(1, None)
         assert repo.get(1) is None

src/infra/subscription.py

@@ -5,7 +5,7 @@ from typing import TYPE_CHECKING
 from datetime import datetime, timedelta
 from src.infra.users import UserModel
 from sqlalchemy.orm import Mapped, mapped_column, relationship, Session, joinedload
-from src.infra.db import Base, CRUDRepo
+from src.infra.db import Base, CRUDRepoImpl
 from sqlalchemy import Engine, ForeignKey, CheckConstraint, DateTime, func, UniqueConstraint, select
 from src.services.subscription import (
     SubscriptionRepo,
@@ -62,7 +62,7 @@ def mutate_subscription(db_sub: SubscriptionModel, sub: Subscription):
     db_sub.sequence_notified = sub.sequence_notified
 
 
-class SubscriptionRepoImpl(SubscriptionRepo, CRUDRepo[SubscriptionModel, Subscription, SubscriptionCreateParams]):
+class SubscriptionRepoImpl(SubscriptionRepo, CRUDRepoImpl[SubscriptionModel, Subscription, SubscriptionCreateParams]):
     def __init__(self, db: Engine):
         super().__init__(
             db, SubscriptionModel, model_to_subscription, mutate_subscription, lambda u: SubscriptionModel(**asdict(u))

src/infra/users.py

@@ -6,7 +6,7 @@ from src.config.email import EmailAddress
 from sqlalchemy import String, VARCHAR, Engine, select
 from sqlalchemy.orm import mapped_column, Mapped, Session, relationship
 from argon2 import PasswordHasher
-from src.infra.db import Base, CRUDRepo
+from src.infra.db import Base, CRUDRepoImpl
 from src.services.users.data import UserDTO, User
 from src.services.users.repo import UserRepo
 
@@ -52,7 +52,7 @@ def make_create_user(hasher: PasswordHasher):
     return create_user
 
 
-class UserRepoImpl(CRUDRepo[UserModel, User, UserDTO], UserRepo):
+class UserRepoImpl(CRUDRepoImpl[UserModel, User, UserDTO], UserRepo):
     def __init__(self, db: Engine):
         hasher = PasswordHasher()
         super().__init__(db, UserModel, model_to_user, mutate_user, make_create_user(hasher))

src/services/repo.py

@@ -0,0 +1,20 @@
+from typing import Callable
+import abc
+
+
+class CRUD[T, C](abc.ABC):
+    @abc.abstractmethod
+    def create(self, domain_item: C, verify: Callable[[T], None] | None) -> T:
+        pass
+
+    @abc.abstractmethod
+    def get(self, item_id: int) -> T | None:
+        pass
+
+    @abc.abstractmethod
+    def update(self, item_id: int, transform: Callable[[T], T]) -> T:
+        pass
+
+    @abc.abstractmethod
+    def delete(self, item_id: int, verify: Callable[[T], None] | None):
+        pass

src/services/subscription.py

@@ -1,4 +1,4 @@
-from src.infra.db import CRUD
+from src.services.repo import CRUD
 import abc
 from datetime import datetime
 from src.services.publications import (

src/services/users/repo.py

@@ -1,4 +1,4 @@
-from src.infra.db import CRUD
+from src.services.repo import CRUD
 import abc
 from src.config.email import EmailAddress