feat(sqlalchemy-factory): add SQLAlchemy custom types section to docs

docs/examples/library_factories/sqlalchemy_factory/test_example_4.py

@@ -0,0 +1,31 @@
+import datetime
+from typing import Any
+
+from sqlalchemy import DateTime, types
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+from polyfactory.factories.sqlalchemy_factory import SQLAlchemyFactory
+
+
+class TZAwareDateTime(types.TypeDecorator):
+    impl = DateTime(timezone=True)
+
+
+class Base(DeclarativeBase):
+    ...
+
+
+class Author(Base):
+    __tablename__ = "authors"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    first_publication_at: Mapped[Any] = mapped_column(type_=TZAwareDateTime(), nullable=False)
+
+
+class AuthorFactory(SQLAlchemyFactory[Author]):
+    __model__ = Author
+
+
+def test_sqla_type_decorator_custom_type_factory() -> None:
+    author = AuthorFactory.build()
+    assert isinstance(author.first_publication_at, datetime.datetime)

docs/examples/library_factories/sqlalchemy_factory/test_example_5.py

@@ -0,0 +1,35 @@
+import datetime
+from typing import Any, Callable, Dict
+
+from sqlalchemy import types
+from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column
+
+from polyfactory.factories.sqlalchemy_factory import SQLAlchemyFactory
+
+
+class CustomType(types.UserDefinedType):
+    ...
+
+
+class Base(DeclarativeBase):
+    ...
+
+
+class Author(Base):
+    __tablename__ = "authors"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    first_publication_at: Mapped[Any] = mapped_column(type_=CustomType())
+
+
+class AuthorFactory(SQLAlchemyFactory[Author]):
+    __model__ = Author
+
+    @classmethod
+    def get_sqlalchemy_types(cls) -> Dict[Any, Callable[[], Any]]:
+        return {**super().get_sqlalchemy_types(), CustomType: lambda: cls.__faker__.date_time()}
+
+
+def test_sqla_user_defined_type_custom_type_factory() -> None:
+    author = AuthorFactory.build()
+    assert isinstance(author.first_publication_at, datetime.datetime)

docs/usage/library_factories/sqlalchemy_factory.rst

@@ -36,6 +36,29 @@ By default, this will add generated models to the session and then commit. This
 
 Similarly for ``__async_session__`` and ``create_async``.
 
+SQLAlchemy custom types
+------------------------------
+
+TypeDecorator based
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Type will be inferred from SQLAlchemy type defined in ``impl``.
+
+.. literalinclude:: /examples/library_factories/sqlalchemy_factory/test_example_4.py
+    :caption: Custom types with TypeDecorator
+    :language: python
+
+
+UserDefinedType based
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+``get_sqlalchemy_types`` classmethod needs to be overridden to provide factory function for custom type.
+
+.. literalinclude:: /examples/library_factories/sqlalchemy_factory/test_example_5.py
+    :caption: Custom types with TypeDecorator
+    :language: python
+
+More info on `SQLAlchemy Custom Types <https://docs.sqlalchemy.org/en/20/core/custom_types.html>`_
 
 API reference
 ------------------------------