Add xfail test capturing missed expectation. Ref #96.

Author: jaraco

tests/test_zipp.py

@@ -408,6 +408,16 @@ def test_suffixes(self, alpharep):
         e = root / '.hgrc'
         assert e.suffixes == []
 
+    import pytest
+
+    @pytest.mark.xfail(reason="96")
+    @pass_alpharep
+    def test_suffix_no_filename(self, alpharep):
+        alpharep.filename = None
+        root = zipp.Path(alpharep)
+        assert root.joinpath('example').suffix == ""
+        assert root.joinpath('example').suffixes == []
+
     @pass_alpharep
     def test_stem(self, alpharep):
         """