Migration Guide

Note

This guide is for an unrelease version of polyfactory.

For v2 to v3 migration, this is largely deprecation internal parameters and updating defaults to be more aligned with common use cases.

SQLAlchemyFactory Default Changes

In the latest version, we’ve made changes to the default behavior of SQLAlchemyFactory to better align with common use cases. Here are the key changes and how to migrate:

Default Relationship Behavior

Before:

  • __set_relationships__ defaulted to False

  • Relationships were not automatically populated unless explicitly enabled

After:

  • __set_relationships__ now defaults to True

  • Relationships are automatically populated by default

To maintain the previous behavior, explicitly set __set_relationships__ = False on your factory.

Model Validation Behavior

Before:

  • __check_model__ defaulted to False

  • Model structure validation was disabled by default

After:

  • __check_model__ now defaults to True

  • Model structure validation is enabled by default

  • This helps catch potential issues with model definitions early

To maintain the previous behavior, explicitly set __check_model__ = False on your factory.

Fixture Field Removal

The polyfactory.fields.Fixture field has been removed in v3. This was a legacy field that was used to define factory behavior through a separate pytest fixture.

Instead, all factories can be used directly as factories as fields. For batch usage, this can be combined with Use or similar.

Internal Parameter Changes

Several internal parameters have been removed or changed in v3 to simplify FieldMeta and typing utils to be deterministic. Usage of random.Random parameters should be removed as per warning emitted.