refactor: migrate to keyword-based repository config, add nested transactions and tests

tests/test_container.py

@@ -1,7 +1,8 @@
+import pytest
 from sqlalchemy.ext.asyncio import AsyncEngine
 
 from metaorm import RepositoriesContainer
-from tests.models import UserRepository
+from tests.models import User, UserRepository
 
 
 class TestRepositoriesContainer:
@@ -39,6 +40,69 @@ class TestRepositoriesContainer:
         ):
             assert inner_session is outer_session
 
+    async def test_nested_transaction_creates_session(
+        self,
+        repositories_container: RepositoriesContainer,
+    ) -> None:
+        assert repositories_container.session is None
+
+        async with repositories_container.nested_transaction() as session:
+            assert session is not None
+            assert repositories_container.session is session
+
+        assert repositories_container.session is None
+
+    async def test_nested_transaction_reuses_outer_session(
+        self,
+        repositories_container: RepositoriesContainer,
+    ) -> None:
+        async with (
+            repositories_container.transaction() as outer_session,
+            repositories_container.nested_transaction() as inner_session,
+        ):
+            assert inner_session is outer_session
+
+    async def test_nested_transaction_rollbacks_on_exception(
+        self,
+        repositories_container: RepositoriesContainer,
+    ) -> None:
+        repository = repositories_container.get_repository(UserRepository)
+        await repository.create_tables()
+
+        with pytest.raises(ValueError):
+            async with repositories_container.nested_transaction():
+                await repository.create_item(
+                    User(name="Alice", email="alice@example.com"),
+                )
+                raise ValueError("boom")
+
+        count = await repository.get_items_count()
+        assert count == 0
+
+    async def test_nested_transaction_in_outer_transaction_rollbacks_only_inner(
+        self,
+        repositories_container: RepositoriesContainer,
+    ) -> None:
+        repository = repositories_container.get_repository(UserRepository)
+        await repository.create_tables()
+
+        async with repositories_container.transaction():
+            await repository.create_item(
+                User(name="Bob", email="bob@example.com"),
+            )
+            with pytest.raises(ValueError):
+                async with repositories_container.nested_transaction():
+                    await repository.create_item(
+                        User(name="Alice", email="alice@example.com"),
+                    )
+                    raise ValueError("boom")
+
+        count = await repository.get_items_count()
+        assert count == 1
+
+        items = [item async for item in repository.get_items()]
+        assert items[0].name == "Bob"
+
     async def test_get_repository_returns_repository_instance(
         self,
         repositories_container: RepositoriesContainer,