Add support for m2m changes in AbstractLogEntry.changes_str

[marco-thirona]

Fixes #585

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.33%. Comparing base (ede4d10) to head (42b4ea5).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #798      +/-   ##
==========================================
+ Coverage   95.92%   96.33%   +0.41%     
==========================================
  Files          35       35              
  Lines        1252     1256       +4     
==========================================
+ Hits         1201     1210       +9     
+ Misses         51       46       -5     

☔ 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.

[hramezani]

Thanks @marco-thirona for the PR.

Could you please fix the failing test and add a change log entry?

@2ykwang Could you please review the PR?

[2ykwang]

Thanks for the PR! I'll review this over the weekend. @marco-thirona

before that, could you please:

1. Check the failing CI test (PostgreSQL, Python 3.13)
2. Add a CHANGELOG.md

[marco-thirona]

before that, could you please:

1. Check the failing CI test (PostgreSQL, Python 3.13)
2. Add a CHANGELOG.md

@2ykwang The test that was failing in the previous build is flaky, I'm afraid:

  ======================================================================
  ERROR: test_log_entry_deleted_fk_changes_to_string_objects_in_display_dict (auditlog_tests.tests.TestRelatedDiffs.test_log_entry_deleted_fk_changes_to_string_objects_in_display_dict)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "/home/runner/work/django-auditlog/django-auditlog/auditlog_tests/tests.py", line 2393, in test_log_entry_deleted_fk_changes_to_string_objects_in_display_dict
      display_dict["related"][0], f"Deleted 'SimpleModel' ({one_simple_id})"
      ~~~~~~~~~~~~^^^^^^^^^^^
  KeyError: 'related'
  
  ----------------------------------------------------------------------

I just added a changelog note, and now the builds are fine again.

[2ykwang]

Thanks @marco-thirona
sorry for the late review. just a quick comment.

[2ykwang]

@marco-thirona
small suggestion: Sequence includes str as well (though unlikely to cause issues in practice).
How about isinstance(value, (list, tuple)) to make the intent clearer?

also, adding a length check like len(value) == 2 might be nice.

[marco-thirona]

Great suggestions @2ykwang, I'll make these changes

[2ykwang]

Sorry for the late review! Left a small suggestion.
let me know what you think 😃

[2ykwang]

for field, value in sorted(self.changes_dict.items()):
    if isinstance(value, (list, tuple)) and len(value) == 2:
        # handle regular field change
    elif isinstance(value, dict) and value.get("type") == "m2m":
        # handle m2m change

What do you think about restructuring it this way? Given the current design, mixed types won't occur,
but this would iterate only once and improve readability.

[marco-thirona]

True that log entries do not currently mix regular and m2m changes, though this approach looks cleaner indeed, so I'll restructure as you proposed. Thanks for the suggestion

[2ykwang]

and thank you for working on this! @marco-thirona

[2ykwang]

thanks! @marco-thirona

[2ykwang]

@hramezani could you double-check this when you have a moment?

[hramezani]

Thanks both