Fix backward compatibility for DagRunInfo partition fields

[bramhanandlingala]

What

This PR restores backward compatibility for custom timetables that were written against Airflow 3.1.x.

Airflow 3.2 introduced partition_date and partition_key fields in DagRunInfo. Since these fields were required, existing custom timetables constructing DagRunInfo with only run_after and data_interval raise a TypeError, causing scheduling to stop.

Why

Custom timetable DAGs fail to schedule after upgrading to Airflow 3.2.x:

DagRunInfo(
run_after=run_after,
data_interval=data_interval,
)

raises:

TypeError: DagRunInfo.__new__() missing 2 required positional arguments:
'partition_date' and 'partition_key'

This can result in DAGs showing an empty Next Run field and no scheduled DAG runs being created.

Changes

• Added default None values for:

  • partition_date
  • partition_key

• Added a regression test to verify backward compatibility with the legacy DagRunInfo constructor.

Testing

Added unit test covering construction of DagRunInfo using the pre-3.2 API and verified default values are correctly assigned to the new partition fields.

Fixes#68315

Gen-AI disclosure: I used a generative AI tool to help identify the root
cause, write tests, and draft the PR description. I reviewed, tested, and
verified all changes locally before submitting.

Was generative AI tooling used to co-author this PR?

• Yes — Claude

Generated-by: Claude following the guidelines

[bramhanandlingala]

Hi @uranusjr , @Lee-W

Can you please review the code and merge the changes. Thanks in advance.

[bramhanandlingala]

Hi @uranusjr , @Lee-W

This PR addresses #68315 by restoring backward compatibility for custom timetables that construct DagRunInfo using the pre-3.2 API.

A regression test has also been added to cover this behavior.

Could someone please review the implementation and approve the pending workflows?

Can you please review the code and merge the changes. Thanks in advance.

Thank you!

[bramhanandlingala]

Fixed the CI formatting issues (ruff-format and end-of-file-fixer) and pushed the updates.

[Lee-W]

I'll fix the blank line and then we can merge it

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.