tests don't use pytest.warns(None) (#6890)

* test_backends don't use pytest.warns(None)

* remove unrelated line

* fix warnings filters

* another one

Author: mathause

xarray/tests/test_backends.py

@@ -2697,7 +2697,6 @@ def create_store(self):
         with create_tmp_file() as tmp_file:
             yield backends.H5NetCDFStore.open(tmp_file, "w")
 
-    @pytest.mark.filterwarnings("ignore:complex dtypes are supported by h5py")
     @pytest.mark.parametrize(
         "invalid_netcdf, warntype, num_warns",
         [
@@ -2719,7 +2718,7 @@ def create_store(self):
     def test_complex(self, invalid_netcdf, warntype, num_warns):
         expected = Dataset({"x": ("y", np.ones(5) + 1j * np.ones(5))})
         save_kwargs = {"invalid_netcdf": invalid_netcdf}
-        with pytest.warns(warntype) as record:
+        with warnings.catch_warnings(record=True) as record:
             with self.roundtrip(expected, save_kwargs=save_kwargs) as actual:
                 assert_equal(expected, actual)
 
@@ -2747,6 +2746,7 @@ def test_complex_error(self, invalid_netcdf):
             with self.roundtrip(expected, save_kwargs=save_kwargs) as actual:
                 assert_equal(expected, actual)
 
+    @pytest.mark.filterwarnings("ignore:You are writing invalid netcdf features")
     def test_numpy_bool_(self):
         # h5netcdf loads booleans as numpy.bool_, this type needs to be supported
         # when writing invalid_netcdf datasets in order to support a roundtrip

xarray/tests/test_backends_file_manager.py

@@ -10,6 +10,7 @@
 from xarray.backends.file_manager import CachingFileManager
 from xarray.backends.lru_cache import LRUCache
 from xarray.core.options import set_options
+from xarray.tests import assert_no_warnings
 
 
 @pytest.fixture(params=[1, 2, 3, None])
@@ -38,8 +39,8 @@ def test_file_manager_mock_write(file_cache) -> None:
     lock.__enter__.assert_has_calls([mock.call(), mock.call()])
 
 
-@pytest.mark.parametrize("expected_warning", [None, RuntimeWarning])
-def test_file_manager_autoclose(expected_warning) -> None:
+@pytest.mark.parametrize("warn_for_unclosed_files", [True, False])
+def test_file_manager_autoclose(warn_for_unclosed_files) -> None:
     mock_file = mock.Mock()
     opener = mock.Mock(return_value=mock_file)
     cache: dict = {}
@@ -48,8 +49,14 @@ def test_file_manager_autoclose(expected_warning) -> None:
     manager.acquire()
     assert cache
 
-    with set_options(warn_for_unclosed_files=expected_warning is not None):
-        with pytest.warns(expected_warning):
+    # can no longer use pytest.warns(None)
+    if warn_for_unclosed_files:
+        ctx = pytest.warns(RuntimeWarning)
+    else:
+        ctx = assert_no_warnings()
+
+    with set_options(warn_for_unclosed_files=warn_for_unclosed_files):
+        with ctx:
             del manager
             gc.collect()