UNSET default value does not work for optional fields when using strawberry.field()

[pavelbrych]

When using UNSET to differentiate between null/None and value not set, everything works when setting UNSET as default directly:

title: typing.Optional[str] = UNSET

but when using strawberry.field(), so we can add field description:

title: typing.Optional[str] = strawberry.field(description="Item title", default=UNSET)

request throws error:

"SampleClass.__init__() missing 1 required positional argument: 'title'"

Probably because StrawberryField class converts default argument from UNSET to dataclasses.MISSING, which does not behave the same.

edit: using title: typing.Optional[str] = dataclasses.MISSING works without error, so my assumption about this conversion beeing the problem may be wrong.

Strawberry version 0.130.4 Python 3.10

[patrick91]

Hi @pavelbrych, this is a bug, if needed the current workaround is this:

title: typing.Optional[str] = strawberry.field(description="Item title", default_factory=lambda: UNSET)

[coady]

Duplicate of #439, and fixed in #2128.