DM-56065: Fix exception-causing bug when 0 job arguments.

[MichelleGower]

Checklist

• ran Jenkins
• added a release note for user-visible changes to doc/changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.35%. Comparing base (e0b1e65) to head (289d4b3).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #106      +/-   ##
==========================================
+ Coverage   88.23%   88.35%   +0.11%     
==========================================
  Files          21       21              
  Lines        5006     5040      +34     
  Branches      500      502       +2     
==========================================
+ Hits         4417     4453      +36     
  Misses        499      499              
+ Partials       90       88       -2     

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[tcjennings]

This is the kind of error that mypy and other static type checkers are designed to prevent. In fact, it looks like there are more of exactly this potential runtime error that might be worth fixing up in this fix.

python/lsst/ctrl/bps/htcondor/lssthtc.py:1522: error: Name "job_type" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/lssthtc.py:1753: error: Name "wms_workflow_id" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/lssthtc.py:1784: error: Name "wms_workflow_id" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/lssthtc.py:2231: error: Name "last_warning" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/prepare_utils.py:383: error: Name "arguments" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/prepare_utils.py:386: error: Name "arguments" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/report_utils.py:129: error: Name "dag_ad" may be undefined  [possibly-undefined]

[MichelleGower]

This is the kind of error that mypy and other static type checkers are designed to prevent. In fact, it looks like there are more of exactly this potential runtime error that might be worth fixing up in this fix.

python/lsst/ctrl/bps/htcondor/lssthtc.py:1522: error: Name "job_type" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/lssthtc.py:1753: error: Name "wms_workflow_id" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/lssthtc.py:1784: error: Name "wms_workflow_id" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/lssthtc.py:2231: error: Name "last_warning" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/prepare_utils.py:383: error: Name "arguments" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/prepare_utils.py:386: error: Name "arguments" may be undefined  [possibly-undefined]
python/lsst/ctrl/bps/htcondor/report_utils.py:129: error: Name "dag_ad" may be undefined  [possibly-undefined]

I fixed all of the "may be undefined" reported by mypy --enable-error-code possibly-undefined python.