docs: SQLAlchemyInitPlugin to SQLAlchemyPlugin fixes SerializationException for docs (#3475)

* Update sqlalchemy_declarative_models.py

Now uses the SQLAlchemyPlugin in stead of SQLAlchemyInitPlugin, see #3464

* Update sqlalchemy_declarative_models.py

Ruff lint fixes

* Update docs/examples/contrib/sqlalchemy/sqlalchemy_declarative_models.py

create_all flag

Co-authored-by: Cody Fincher <[email protected]>

* Update docs/examples/contrib/sqlalchemy/sqlalchemy_declarative_models.py

Co-authored-by: Peter Schutt <[email protected]>

* Update docs/examples/contrib/sqlalchemy/sqlalchemy_declarative_models.py

Further documentation

Co-authored-by: Peter Schutt <[email protected]>

* Update docs/examples/contrib/sqlalchemy/sqlalchemy_declarative_models.py

Co-authored-by: Peter Schutt <[email protected]>

* Update docs/examples/contrib/sqlalchemy/sqlalchemy_declarative_models.py

Co-authored-by: Cody Fincher <[email protected]>

* Unit test for sqlalchemy_declarative_models.

* Now using option create_all=True for meta-data, on_startup for dummy data

* Lint ruff-format compatibility

* Fix for 3.9 and 3.10 wrt class declarations/typing

* Ruff format check

* Removed comments which might be heavy for example code

* For 3.8 compatibility wrt typing now using List in stead of list

* Replaced incorrect use of List instead of List

---------

Co-authored-by: Cody Fincher <[email protected]>
Co-authored-by: Peter Schutt <[email protected]>

Author: 3 people

docs/examples/contrib/sqlalchemy/sqlalchemy_declarative_models.py

@@ -1,24 +1,25 @@
+from __future__ import annotations
+
+import uuid
 from datetime import date
-from typing import TYPE_CHECKING
+from typing import List
 from uuid import UUID
 
-from sqlalchemy import ForeignKey, select
+from sqlalchemy import ForeignKey, func, select
+from sqlalchemy.ext.asyncio import AsyncEngine, AsyncSession
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from litestar import Litestar, get
 from litestar.contrib.sqlalchemy.base import UUIDAuditBase, UUIDBase
-from litestar.contrib.sqlalchemy.plugins import AsyncSessionConfig, SQLAlchemyAsyncConfig, SQLAlchemyInitPlugin
-
-if TYPE_CHECKING:
-    from sqlalchemy.ext.asyncio import AsyncEngine, AsyncSession
+from litestar.contrib.sqlalchemy.plugins import AsyncSessionConfig, SQLAlchemyAsyncConfig, SQLAlchemyPlugin
 
 
 # the SQLAlchemy base includes a declarative model for you to use in your models.
 # The `Base` class includes a `UUID` based primary key (`id`)
 class Author(UUIDBase):
     name: Mapped[str]
     dob: Mapped[date]
-    books: Mapped[list["Book"]] = relationship(back_populates="author", lazy="selectin")
+    books: Mapped[List[Book]] = relationship(back_populates="author", lazy="selectin")
 
 
 # The `AuditBase` class includes the same UUID` based primary key (`id`) and 2
@@ -32,25 +33,31 @@ class Book(UUIDAuditBase):
 
 session_config = AsyncSessionConfig(expire_on_commit=False)
 sqlalchemy_config = SQLAlchemyAsyncConfig(
-    connection_string="sqlite+aiosqlite:///test.sqlite", session_config=session_config
+    connection_string="sqlite+aiosqlite:///test.sqlite", session_config=session_config, create_all=True
 )  # Create 'async_session' dependency.
-sqlalchemy_plugin = SQLAlchemyInitPlugin(config=sqlalchemy_config)
 
 
 async def on_startup() -> None:
-    """Initializes the database."""
-    async with sqlalchemy_config.get_engine().begin() as conn:
-        await conn.run_sync(UUIDBase.metadata.create_all)
+    """Adds some dummy data if no data is present."""
+    async with sqlalchemy_config.get_session() as session:
+        statement = select(func.count()).select_from(Author)
+        count = await session.execute(statement)
+        if not count.scalar():
+            author_id = uuid.uuid4()
+            session.add(Author(name="Stephen King", dob=date(1954, 9, 21), id=author_id))
+            session.add(Book(title="It", author_id=author_id))
+            await session.commit()
 
 
 @get(path="/authors")
-async def get_authors(db_session: "AsyncSession", db_engine: "AsyncEngine") -> list[Author]:
+async def get_authors(db_session: AsyncSession, db_engine: AsyncEngine) -> List[Author]:
     """Interact with SQLAlchemy engine and session."""
     return list(await db_session.scalars(select(Author)))
 
 
 app = Litestar(
     route_handlers=[get_authors],
     on_startup=[on_startup],
-    plugins=[SQLAlchemyInitPlugin(config=sqlalchemy_config)],
+    debug=True,
+    plugins=[SQLAlchemyPlugin(config=sqlalchemy_config)],
 )

pyproject.toml

@@ -395,6 +395,7 @@ known-first-party = ["litestar", "tests", "examples"]
 "docs/examples/application_hooks/before_send_hook.py" = ["UP006"]
 "docs/examples/contrib/sqlalchemy/plugins/**/*.*" = ["UP006"]
 "docs/examples/data_transfer_objects**/*.*" = ["UP006"]
+"docs/examples/contrib/sqlalchemy/sqlalchemy_declarative_models.py" = ["UP006"]
 "litestar/_openapi/schema_generation/schema.py" = ["C901"]
 "litestar/exceptions/*.*" = ["N818"]
 "litestar/handlers/**/*.*" = ["N801"]

tests/examples/test_contrib/test_sqlalchemy/test_sqlalchemy_examples.py

@@ -0,0 +1,14 @@
+import pytest
+
+from litestar.testing import TestClient
+
+pytestmark = pytest.mark.xdist_group("sqlalchemy_examples")
+
+
+def test_sqlalchemy_declarative_models() -> None:
+    from docs.examples.contrib.sqlalchemy.sqlalchemy_declarative_models import app
+
+    with TestClient(app) as client:
+        response = client.get("/authors")
+        assert response.status_code == 200
+        assert len(response.json()) > 0