Fix unit tests CosmosRichLogger crash on None msg and test pollution

[tatiana]

Although the unittests are passing in the CI, there are a few failing locally. An example, when running:

AIRFLOW_HOME=`pwd` hatch run tests.py3.10-3.1-1.11:test-cov

I was seeing:

FAILED                                 
tests/airflow/test_graph.py::test_create_task_metadata_unsupported - AssertionError: assert equals failed                                                            
  '\x1b[35m(astronomer-cosmos)\x1b[0m Unavailable conversion function for <u  'Unavailable conversion function for <unsupported> (node <unsupported.dbt-             
  nsupported> (node <unsupported.dbt-proj.unsupported>). Define a converter   proj.unsupported>). Define a converter function using render_config.node_c             
  function using render_config.node_converters.'    and also FAILED tests/dbt/test_selector.py::test_select_nodes_by_invalid_config - AssertionError: assert         
'Unsupported config key selector: invalid_config' in ['\x1b[35m(astronomer-cosmos)\x1b[0m Unsupported config key selector: invalid_config']                          
 +  where ['\x1b[35m(astronomer-cosmos)\x1b[0m Unsupported config key selector: invalid_config'] = <_pytest.logging.LogCaptureFixture object at                      
0x16f34f730>.messages                                                                                                                                                
FAILED tests/operators/test_kubernetes.py::test_dbt_kubernetes_operator_handle_warnings[\n        19:48:25  Concurrency: 4 threads (target='target')\n               
19:48:25\n        19:48:25  1 of 2 START test dbt_utils_accepted_range_table_col__12__0 ................... [RUN]\n        19:48:25  2 of 2 START test               
unique_table__uuid .......................................... [RUN]\n        19:48:27  1 of 2 WARN dbt_utils_accepted_range_table_col__12__0 .....................   
[WARN in 1.83s]\n        19:48:27  2 of 2 PASS unique_table__uuid ................................................ [PASS in 1.85s]\n        19:48:27\n               
19:48:27  Finished running 2 tests, 1 hook in 0 hours 0 minutes and 12.86 seconds (12.86s).\n        19:48:27\n        19:48:27  Completed with 1 warning:\n         
19:48:27\n        19:48:27  Warning in test dbt_utils_accepted_range_table_col__12__0 (models/ads/ads.yaml)\n        19:48:27  Got 252 results, configured to warn   
if >0\n        19:48:27\n        19:48:27    compiled Code at target/compiled/model/models/table/table.yaml/dbt_utils_accepted_range_table_col__12__0.sql\n          
19:48:27\n        19:48:27  Done. PASS=1 WARN=1 ERROR=0 SKIP=0 TOTAL=2\n        19:48:27  Command `dbt test` succeeded at 07:50:02.340364 after 43.98 seconds\n      
   19:48:27  Flushing usage events\n        -True] - TypeError: can only concatenate str (not "NoneType") to str                                                     
FAILED tests/operators/test_kubernetes.py::test_dbt_kubernetes_operator_handle_warnings[\n        19:48:25  Concurrency: 4 threads (target='target')\n               
19:48:25\n        19:48:25  1 of 2 START test dbt_utils_accepted_range_table_col__12__0 ................... [RUN]\n        19:48:25  2 of 2 START test               
unique_table__uuid .......................................... [RUN]\n        19:48:27  1 of 2 PASS 252 dbt_utils_accepted_range_table_col__12__0                     
..................... [PASS in 1.83s]\n        19:48:27  2 of 2 PASS unique_table__uuid ................................................ [PASS in 1.85s]\n           
19:48:27\n        19:48:27  Finished running 2 tests, 1 hook in 0 hours 0 minutes and 12.86 seconds (12.86s).\n        19:48:27\n        19:48:27  Done. PASS=2      
WARN=0 ERROR=0 SKIP=0 TOTAL=2\n        -False] - TypeError: can only concatenate str (not "NoneType") to str                                                         
FAILED tests/operators/test_kubernetes.py::test_dbt_kubernetes_operator_handle_warnings[\n        gibberish\n        -False] - TypeError: can only concatenate str   
(not "NoneType") to str                                        

The problems seemed to be:

• CosmosRichLogger.handle() crashed with TypeError when record.msg was None (e.g. logging a None return value). Guard against this by checking for None and converting to str.
• Add an autouse fixture in conftest.py that demotes any CosmosRichLogger instances back to logging.Logger after each test. This prevents test_log.py (which monkeypatches rich_logging=True) from permanently polluting the logging cache with CosmosRichLogger instances that add the (astronomer-cosmos) prefix to subsequent tests.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.08%. Comparing base (678e508) to head (5df3617).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2540   +/-   ##
=======================================
  Coverage   98.08%   98.08%           
=======================================
  Files         103      103           
  Lines        7482     7483    +1     
=======================================
+ Hits         7339     7340    +1     
  Misses        143      143           

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[Copilot]

Pull request overview

This PR addresses local unit test failures caused by CosmosRichLogger crashing when a LogRecord has msg=None, and by cross-test pollution from cached CosmosRichLogger instances that unintentionally prepend the (astronomer-cosmos) prefix in unrelated tests.

Changes:

• Add a guard in CosmosRichLogger.handle() to avoid TypeError when record.msg is None.
• Add an autouse pytest fixture to demote cached CosmosRichLogger instances back to standard logging.Logger after each test run.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
tests/conftest.py	Adds an autouse fixture to clean up cached CosmosRichLogger instances between tests to prevent log-prefix pollution.
cosmos/log.py	Updates CosmosRichLogger.handle() to avoid crashing when record.msg is None.

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