TST: Added message to bare pytest.raises in test_join_multi_levels (pandas-dev#30999) (pandas-dev#33806)

Author: Dom-L-G

pandas/tests/reshape/merge/test_multi.py

@@ -582,13 +582,15 @@ def test_join_multi_levels(self):
         # invalid cases
         household.index.name = "foo"
 
-        with pytest.raises(ValueError):
+        with pytest.raises(
+            ValueError, match="cannot join with no overlapping index names"
+        ):
             household.join(portfolio, how="inner")
 
         portfolio2 = portfolio.copy()
         portfolio2.index.set_names(["household_id", "foo"])
 
-        with pytest.raises(ValueError):
+        with pytest.raises(ValueError, match="columns overlap but no suffix specified"):
             portfolio2.join(portfolio, how="inner")
 
     def test_join_multi_levels2(self):