Invalid JSON parsing datetime items

[solracfs]

Description of the issue:
An invalid JSON is generated with a dictionary that has a datetime item, instead of throwing an exception

Expected result:
TypeError: datetime.datetime(...) is not JSON serializable

Actual result:
The function returns an invalid encoded JSON with empty value:
{"d":,"n":null}

Versions:

• OS: Ubuntu 19.10
• Python: 3.7.5
• UltraJSON: 3.0.0

Code to reproduce the issue:

import ujson
from datetime import datetime

print(ujson.dumps({ "d": datetime.now(), "n": None }))

[shinybrar]

I can confirm the issue has been around since release version 2.0.1, where as 1.35 works as expected.

3.0

import ujson
from datetime import datetime
print(ujson.dumps({ "d": datetime.now(), "n": None }))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: datetime.datetime(2020, 6, 5, 16, 8, 50, 798045) is not JSON serializable

2.0.1

import ujson
from datetime import datetime
print(ujson.dumps({ "d": datetime.now(), "n": None }))

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: � is not JSON serializable

1.35

 import ujson
from datetime import datetime
print(ujson.dumps({ "d": datetime.now(), "n": None }))
{"d":1591372908,"n":null}

Edit: Can also confirm, none of the releases between 2.0.1 and 3.0 seem to work.

[solracfs]

Thanks for checking, @shinybrar.

According to your output, it seems that the test code is throwing a TypeError exception in your tests.
This is the expected result, since support for datetime objects was removed in version 2.
However, this is not the same result as mine. Note the empty value for "d":

{"d":,"n":null}

To avoid differences in OS, python versions, etc., I have tested the code in a docker container:

Dockerfile:

FROM python:3.8.3

WORKDIR /usr/src/app

RUN pip install ujson

CMD ["python", "-c", "import ujson;from datetime import datetime;print(ujson.dumps({ 'd': datetime.now(), 'n': None }))"]

$ docker build -t test-ujson-app .
$ docker run -it --rm --name test-ujson-app test-ujson-app

Output:

{"d":,"n":null}

NOTE: if you remove the None element, leaving only the datetime value, it works as expected, throwing a TypeError exception.

[shinybrar]

@solracfs Thanks for the clarification. I think the exception due to deprecation makes sense.

[champax]

Though i understand that json standard do not defines date serialization and that support removal is compliant with this, ujson do not support for dumps(d, cls=MyEncoder) as standard json lib support.
We are using ujson for performance reason, i will not patch bunches of client code neither massive json input coming from external stuff to handle custom pre-sererialization before calling ujson.dumps

At this stage, i have to revert to json...

I saw bunches of issues related to this into ujson, but the support from "cls=" was never put in place. Do we have a chance to have this one day?

[JustAnotherArchivist]

I can no longer reproduce this with ujson 5.2.0. I think it was probably fixed by #505.

[hugovk]

Thanks, let's close!