config: Do not fail if a warning filter category cannot be imported

Author: isra17

changelog/13732.contrib.rst

@@ -0,0 +1 @@
+Do not fail when a warning category cannot be imported. Log a warning instead.

src/_pytest/config/__init__.py

@@ -1965,6 +1965,8 @@ def parse_warning_filter(
  raise UsageError(error_template.format(error=str(e))) from None
  try:
  category: type[Warning] = _resolve_warning_category(category_)
+ except ImportError:
+ raise
  except Exception:
  exc_info = ExceptionInfo.from_current()
  exception_text = exc_info.getrepr(style="native")
@@ -2023,7 +2025,15 @@ def apply_warning_filters(
  # Filters should have this precedence: cmdline options, config.
  # Filters should be applied in the inverse order of precedence.
  for arg in config_filters:
- warnings.filterwarnings(*parse_warning_filter(arg, escape=False))
+ try:
+ warnings.filterwarnings(*parse_warning_filter(arg, escape=False))
+ except ImportError as e:
+ warnings.warn(f"Failed to import filter module '{e.name}': {arg}", PytestConfigWarning)
+ continue
 
  for arg in cmdline_filters:
- warnings.filterwarnings(*parse_warning_filter(arg, escape=True))
+ try:
+ warnings.filterwarnings(*parse_warning_filter(arg, escape=True))
+ except ImportError as e:
+ warnings.warn(f"Failed to import filter module '{e.name}': {arg}", PytestConfigWarning)
+ continue

testing/test_warnings.py

@@ -424,6 +424,26 @@ def test():
  result.stdout.fnmatch_lines(["* 1 failed in*"])
 
 
+def test_accept_unknown_category(pytester: Pytester) -> None:
+ """Filters defined by marks should always take precedence (#3946)."""
+ pytester.makeini(
+ """
+ [pytest]
+ filterwarnings =
+ ignore:Failed to import filter module.*:pytest.PytestConfigWarning
+ ignore::foobar.Foobar
+ """
+ )
+ pytester.makepyfile(
+ """
+ def test():
+ pass
+ """
+ )
+ result = pytester.runpytest("-W", "ignore::bizbaz.Bizbaz")
+ result.stdout.fnmatch_lines(["* 1 passed in*"])
+
+
 class TestDeprecationWarningsByDefault:
  """
  Note: all pytest runs are executed in a subprocess so we don't inherit warning filters