Fix unit test failure

Author: Roline Stapny Saldanha

pandas/tests/copy_view/test_functions.py

@@ -243,6 +243,10 @@ def test_merge_copy_keyword():
     assert np.shares_memory(get_array(df2, "b"), get_array(result, "b"))
 
 
+@pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
 @pytest.mark.parametrize("dtype", [object, "str"])
 def test_join_on_key(dtype):
     df_index = Index(["a", "b", "c"], name="key", dtype=dtype)
@@ -271,6 +275,10 @@ def test_join_on_key(dtype):
     tm.assert_frame_equal(df2, df2_orig)
 
 
+@pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
 def test_join_multiple_dataframes_on_key():
     df_index = Index(["a", "b", "c"], name="key", dtype=object)
 

pandas/tests/indexes/multi/test_join.py

@@ -208,6 +208,10 @@ def test_join_midx_string():
     tm.assert_index_equal(result, expected)
 
 
+@pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
 def test_join_multi_with_nan():
     # GH29252
     df1 = DataFrame(

pandas/tests/reshape/merge/test_join.py

@@ -20,6 +20,11 @@
 )
 import pandas._testing as tm
 
+pytestmark = pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
+
 
 def get_test_data(ngroups=8, n=50):
     unique_groups = list(range(ngroups))

pandas/tests/reshape/merge/test_merge.py

@@ -35,6 +35,11 @@
     merge,
 )
 
+pytestmark = pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
+
 
 def get_test_data(ngroups=8, n=50):
     unique_groups = list(range(ngroups))

pandas/tests/reshape/merge/test_merge_cross.py

@@ -88,6 +88,10 @@ def test_merge_cross_null_values(nulls_fixture):
     tm.assert_frame_equal(result, expected)
 
 
+@pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
 def test_join_cross_error_reporting():
     # GH#5401
     left = DataFrame({"a": [1, 3]})

pandas/tests/reshape/merge/test_multi.py

@@ -17,6 +17,11 @@
 from pandas.core.reshape.concat import concat
 from pandas.core.reshape.merge import merge
 
+pytestmark = pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
+
 
 @pytest.fixture
 def left():

pandas/tests/reshape/test_melt.py

@@ -14,6 +14,11 @@
 )
 import pandas._testing as tm
 
+pytestmark = pytest.mark.filterwarnings(
+    r"ignore:The default value of empty string \(''\) for suffix parameters "
+    "is deprecated:DeprecationWarning"
+)
+
 
 @pytest.fixture
 def df():