JP-4122: Fix attribute error in combine_1d log message

[melanieclarke]

Resolves JP-4122

Fix a crash in the master background step for NIRSpec MOS data. When the input background spectra contain no valid flux values, the step issues a warning message. The warning was introduced in #9625 to address some failures in WFSS mode, so was tested with WFSS data. The crash comes from an attempt to log the group_id for the spectrum, which is an attribute that exists for WFSS spectra but not for MOS spectra.

The fix here is to modify the log message to record group_id only if it's present in the datamodel. I added a unit test for this edge case with non-WFSS data.

Tasks

• If you have a specific reviewer in mind, tag them.
• add a build milestone, i.e. Build 12.0 (use the latest build if not sure)
• Does this PR change user-facing code / API? (if not, label with no-changelog-entry-needed)
  • write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see changelog readme for instructions)
  • update or add relevant tests
  • update relevant docstrings and / or docs/ page
  • start a regression test and include a link to the running job (click here for instructions)
    • Do truth files need to be updated ("okified")?
      • after the reviewer has approved these changes, run okify_regtests to update the truth files
• if a JIRA ticket exists, make sure it is resolved properly

[melanieclarke]

Regression tests:
https://github.com/spacetelescope/RegressionTests/actions/runs/17806941595

Failures are all unrelated. I'll run again when tests on main are clear.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.41%. Comparing base (f1db9d7) to head (6cce887).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9848      +/-   ##
==========================================
+ Coverage   84.15%   85.41%   +1.25%     
==========================================
  Files         366      366              
  Lines       37800    37812      +12     
==========================================
+ Hits        31812    32297     +485     
+ Misses       5988     5515     -473     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[emolter]

The fix looks fine to me, pending clean regtests. I assume you checked the original data that caused the failure?

[melanieclarke]

The fix looks fine to me, pending clean regtests. I assume you checked the original data that caused the failure?

Yes -- the test data is jw03788-o007_20250917t012349_spec2_00004_asn.json. With this change, the master_background_mos step warns for three background spectra with no valid flux values but continues processing with the remaining 14 valid spectra.