TST: assert_produces_warning works with filterwarnings (#25721)

Author: TomAugspurger

pandas/tests/util/test_assert_produces_warning.py

@@ -0,0 +1,22 @@
+import warnings
+
+import pytest
+
+import pandas.util.testing as tm
+
+
+def f():
+    warnings.warn('f1', FutureWarning)
+    warnings.warn('f2', RuntimeWarning)
+
+
+@pytest.mark.filterwarnings('ignore:f1:FutureWarning')
+def test_assert_produces_warning_honors_filter():
+    # raise by default
+    with pytest.raises(AssertionError):
+        with tm.assert_produces_warning(RuntimeWarning):
+            f()
+
+    with tm.assert_produces_warning(RuntimeWarning,
+                                    raise_on_extra_warnings=False):
+        f()

pandas/util/testing.py

@@ -2536,7 +2536,8 @@ def exception_matches(self, exc_type, exc_value, trace_back):
 
 @contextmanager
 def assert_produces_warning(expected_warning=Warning, filter_level="always",
-                            clear=None, check_stacklevel=True):
+                            clear=None, check_stacklevel=True,
+                            raise_on_extra_warnings=True):
     """
     Context manager for running code expected to either raise a specific
     warning, or not raise any warnings. Verifies that the code raises the
@@ -2549,7 +2550,7 @@ def assert_produces_warning(expected_warning=Warning, filter_level="always",
         The type of Exception raised. ``exception.Warning`` is the base
         class for all warnings. To check that no warning is returned,
         specify ``False`` or ``None``.
-    filter_level : str, default "always"
+    filter_level : str or None, default "always"
         Specifies whether warnings are ignored, displayed, or turned
         into errors.
         Valid values are:
@@ -2573,6 +2574,9 @@ class for all warnings. To check that no warning is returned,
         If True, displays the line that called the function containing
         the warning to show were the function is called. Otherwise, the
         line that implements the function is displayed.
+    raise_on_extra_warnings : bool, default True
+        Whether extra warnings not of the type `expected_warning` should
+        cause the test to fail.
 
     Examples
     --------
@@ -2641,8 +2645,10 @@ class for all warnings. To check that no warning is returned,
             msg = "Did not see expected warning of class {name!r}.".format(
                 name=expected_warning.__name__)
             assert saw_warning, msg
-        assert not extra_warnings, ("Caused unexpected warning(s): {extra!r}."
-                                    ).format(extra=extra_warnings)
+        if raise_on_extra_warnings and extra_warnings:
+            raise AssertionError(
+                "Caused unexpected warning(s): {!r}.".format(extra_warnings)
+            )
 
 
 class RNGContext(object):