Timestamp not handled correctly

[racinmat]

I have following issue with timestamp and mypy:

mwe.py

import proto
from google.protobuf import timestamp_pb2


class MyClass(proto.Message):
    create_time = proto.Field(
        proto.MESSAGE,
        number=6,
        message=timestamp_pb2.Timestamp,
    )


if __name__ == '__main__':
    classes = [MyClass(create_time=timestamp_pb2.Timestamp(seconds=1, nanos=1)),
               MyClass(create_time=timestamp_pb2.Timestamp(seconds=2, nanos=2))]

    print(f"{max(classes, key=lambda m: m.create_time)=}")

when I run the code, it succeeds:

python .\mwe.py            
max(classes, key=lambda m: m.create_time)=create_time {
  seconds: 2
  nanos: 2
}

but it fails on mypy

mypy .\mwe.py
mwe.py:17: error: Argument "key" to "max" has incompatible type "Callable[[MyClass], Timestamp]"; expected "Callable[[MyClass], Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]]"  [arg-type]
mwe.py:17: error: Incompatible return value type (got "Timestamp", expected "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]")  [return-value]
Found 2 errors in 1 file (checked 1 source file)

I hope this is the right package, because this is an issue between mypy, protobuf, proto-plus and maybe something else.
When I have a Timestamp as a field, the proto-plus turns it into DatetimeWithNanoseconds which has arithmetic defined, because it extends datetime.datetime, but mypy does not know about it.
This is more elaborate example

problem_example.py

"""
conda create -n mypy_experiments python=3.9
conda activate mypy_experiments
"""
from datetime import datetime

import proto
from google.protobuf import timestamp_pb2


class MyClass(proto.Message):
    create_time = proto.Field(
        proto.MESSAGE,
        number=6,
        message=timestamp_pb2.Timestamp,
    )


if __name__ == '__main__':
    classes = [MyClass(create_time=timestamp_pb2.Timestamp(seconds=1, nanos=1)),
               MyClass(create_time=timestamp_pb2.Timestamp(seconds=2, nanos=2))]

    print(f"{max(classes, key=lambda m: m.create_time)=}")

    times = [d.create_time for d in classes]
    print(f"{max(times)=}")
    print(f"{type(times[0])=}, {isinstance(times[0], datetime)=}")
    times2 = [timestamp_pb2.Timestamp(seconds=1, nanos=1), timestamp_pb2.Timestamp(seconds=2, nanos=2)]
    print(f"{type(times2[0])=}, {isinstance(times2[0], datetime)=}")
    try:
        print(f"{max(times2)=}")
    except Exception as e:
        print(e)
    print(f"{max(times, key=lambda t: t)=}")
    try:
        print(f"{max(times2, key=lambda t: t)=}")
    except Exception as e:
        print(e)

which prints

python .\problem_example.py
max(classes, key=lambda m: m.create_time)=create_time {
  seconds: 2
  nanos: 2
}

max(times)=DatetimeWithNanoseconds(1970, 1, 1, 0, 0, 2, tzinfo=datetime.timezone.utc)
type(times[0])=<class 'proto.datetime_helpers.DatetimeWithNanoseconds'>, isinstance(times[0], datetime)=True
type(times2[0])=<class 'google.protobuf.timestamp_pb2.Timestamp'>, isinstance(times2[0], datetime)=False
'>' not supported between instances of 'Timestamp' and 'Timestamp'
max(times, key=lambda t: t)=DatetimeWithNanoseconds(1970, 1, 1, 0, 0, 2, tzinfo=datetime.timezone.utc)
'>' not supported between instances of 'Timestamp' and 'Timestamp'

I am using python 3.9 and here are all versions of packages:

pip freeze
filelock==3.13.1
mypy==1.8.0
mypy-extensions==1.0.0
mypy-protobuf==3.5.0
proto-plus==1.23.0
proto-plus-stubs==0.6.0        
protobuf==4.25.2
requests-file==1.5.1
tldextract==5.1.1
tomli==2.0.1
types-protobuf==4.24.0.20240106
typing_extensions==4.9.0       
XlsxWriter==3.1.9

[henribru]

This is indeed an issue with this package. There's no special-handling of Timestamp currently. I'll see if I can do something about that. Thanks for the heads-up

[henribru]

This is fixed in v0.6.1.

[racinmat]

Thanks! this is great!