From 0519914675764ff183521712e3a7d4e57da1d331 Mon Sep 17 00:00:00 2001
From: mzeitlin11 <37011898+mzeitlin11@users.noreply.github.com>
Date: Tue, 22 Dec 2020 08:40:41 -0500
Subject: [PATCH] Bug: assert_produces_warning(None) not raising AssertionError
 with warning (#38626)

---
 pandas/_testing.py                              |  7 +++----
 pandas/tests/arithmetic/test_timedelta64.py     |  1 +
 pandas/tests/frame/test_arithmetic.py           |  1 +
 pandas/tests/indexes/test_common.py             |  1 +
 pandas/tests/io/parser/test_common.py           |  1 +
 .../tests/util/test_assert_produces_warning.py  | 17 +++++++++++++++++
 6 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/pandas/_testing.py b/pandas/_testing.py
index 2d74cc89b8063..cad95ca571258 100644
--- a/pandas/_testing.py
+++ b/pandas/_testing.py
@@ -2724,11 +2724,10 @@ class for all warnings. To check that no warning is returned,
         extra_warnings = []
 
         for actual_warning in w:
-            if not expected_warning:
-                continue
-
             expected_warning = cast(Type[Warning], expected_warning)
-            if issubclass(actual_warning.category, expected_warning):
+            if expected_warning and issubclass(
+                actual_warning.category, expected_warning
+            ):
                 saw_warning = True
 
                 if check_stacklevel and issubclass(
diff --git a/pandas/tests/arithmetic/test_timedelta64.py b/pandas/tests/arithmetic/test_timedelta64.py
index 092a3f0d4402f..110f55a49eea3 100644
--- a/pandas/tests/arithmetic/test_timedelta64.py
+++ b/pandas/tests/arithmetic/test_timedelta64.py
@@ -543,6 +543,7 @@ def test_tda_add_sub_index(self):
         expected = tdi - tdi
         tm.assert_index_equal(result, expected)
 
+    @pytest.mark.xfail(reason="GH38630", strict=False)
     def test_tda_add_dt64_object_array(self, box_with_array, tz_naive_fixture):
         # Result should be cast back to DatetimeArray
         box = box_with_array
diff --git a/pandas/tests/frame/test_arithmetic.py b/pandas/tests/frame/test_arithmetic.py
index e5ec3c5641bd2..e6d1cd5f47d8d 100644
--- a/pandas/tests/frame/test_arithmetic.py
+++ b/pandas/tests/frame/test_arithmetic.py
@@ -821,6 +821,7 @@ def test_frame_with_frame_reindex(self):
             (np.datetime64(20, "ns"), "<M8[ns]"),
         ],
     )
+    @pytest.mark.xfail(reason="GH38630", strict=False)
     @pytest.mark.parametrize(
         "op",
         [
diff --git a/pandas/tests/indexes/test_common.py b/pandas/tests/indexes/test_common.py
index a10be99dff076..4bd4c9f4d10fc 100644
--- a/pandas/tests/indexes/test_common.py
+++ b/pandas/tests/indexes/test_common.py
@@ -357,6 +357,7 @@ def test_ravel_deprecation(self, index):
         with tm.assert_produces_warning(FutureWarning):
             index.ravel()
 
+    @pytest.mark.xfail(reason="GH38630", strict=False)
     def test_asi8_deprecation(self, index):
         # GH#37877
         if isinstance(
diff --git a/pandas/tests/io/parser/test_common.py b/pandas/tests/io/parser/test_common.py
index df20db0c7ee84..ce3557e098bfd 100644
--- a/pandas/tests/io/parser/test_common.py
+++ b/pandas/tests/io/parser/test_common.py
@@ -1136,6 +1136,7 @@ def test_parse_integers_above_fp_precision(all_parsers):
     tm.assert_frame_equal(result, expected)
 
 
+@pytest.mark.xfail(reason="GH38630, sometimes gives ResourceWarning", strict=False)
 def test_chunks_have_consistent_numerical_type(all_parsers):
     parser = all_parsers
     integers = [str(i) for i in range(499999)]
diff --git a/pandas/tests/util/test_assert_produces_warning.py b/pandas/tests/util/test_assert_produces_warning.py
index 5f87824713175..296fa3b6cf537 100644
--- a/pandas/tests/util/test_assert_produces_warning.py
+++ b/pandas/tests/util/test_assert_produces_warning.py
@@ -152,3 +152,20 @@ def test_right_category_wrong_match_raises(pair_different_warnings):
         with tm.assert_produces_warning(target_category, match=r"^Match this"):
             warnings.warn("Do not match it", target_category)
             warnings.warn("Match this", other_category)
+
+
+@pytest.mark.parametrize("false_or_none", [False, None])
+class TestFalseOrNoneExpectedWarning:
+    def test_raise_on_warning(self, false_or_none):
+        msg = r"Caused unexpected warning\(s\)"
+        with pytest.raises(AssertionError, match=msg):
+            with tm.assert_produces_warning(false_or_none):
+                f()
+
+    def test_no_raise_without_warning(self, false_or_none):
+        with tm.assert_produces_warning(false_or_none):
+            pass
+
+    def test_no_raise_with_false_raise_on_extra(self, false_or_none):
+        with tm.assert_produces_warning(false_or_none, raise_on_extra_warnings=False):
+            f()