support passing optional date through CLI

[blaketastic2]

Why are the changes needed?

Currently, if we have a workflow with an optional date parameter, we cannot call this from the CLI.

Workflow definition:

@workflow
def ingest_data(
    start_date: Optional[date] = None,
) -> None:
    pass

Executing the workflow:

pyflyte run --copy all -p flyte-snacks -d development --remote workflow.py ingest_data --start_date 2025-06-10

Produces this error:

Invalid value for '--start_date': Failed to convert param: <Option start_date>, value: 2025-06-10 00:00:00 to type: typing.Optional[datetime.date]. Reason
Cannot convert from 2025-06-10 00:00:00 to typing.Optional[datetime.date]

What changes were proposed in this pull request?

We are now making sure to use the non-None variant when trying to do the conversion.

Summary by Bito

This pull request enhances the CLI's handling of optional date parameters by improving type conversion, specifically addressing datetime to optional date type conversions to prevent type mismatch errors. These enhancements aim to improve user experience in workflows requiring date parameters.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.85%. Comparing base (3c6b61d) to head (199c8fe).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3273      +/-   ##
==========================================
+ Coverage   83.35%   92.85%   +9.50%     
==========================================
  Files         347       18     -329     
  Lines       28791      812   -27979     
  Branches     2960        0    -2960     
==========================================
- Hits        23999      754   -23245     
+ Misses       3956       58    -3898     
+ Partials      836        0     -836     

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[kumare3]

I think it should be here -

flytekit/flytekit/interaction/click_types.py

Line 517 in b0efdba

if lt.union_type:

[blaketastic2]

@kumare3 Alright, what do you think about this approach?

[blaketastic2]

I'm hoping we can move forward with this

[machichima]

I think we can just modify here and do not need to add a new DateType. While it already deal with the conversion for datetime.date type, what we need to do is to also trigger this conversion for Optional[datetime.date] and datetime.date | None type.

The following should work:

            is_union = typing.get_origin(self._python_type) in (typing.Union, types.UnionType)
            args = typing.get_args(self._python_type)
            is_date_type = (
                (is_union and datetime.date in args)
                or self._python_type is datetime.date
            )

            if is_date_type and isinstance(value, datetime.datetime):
                value = value.date()

[blaketastic2]

Ok, that's fair. I've made the change, so hopefully we can get this merged in soon.

[machichima]

@blaketastic2 Could you fix CI failure? Thanks!

[machichima]

LGTM! Thank you