test: uncomment an assert

Author: nedbat

tests/test_data.py

@@ -794,8 +794,7 @@ def test_combining_with_aliases(self):
         aliases.add(r"c:\ned\test", "./")
         combine_parallel_data(covdata3, aliases=aliases)
         self.assert_file_count(".coverage.*", 0)
-        # covdata3 hasn't been written yet. Should this file exist or not?
-        #self.assert_exists(".coverage")
+        self.assert_exists(".coverage")
 
         apy = canonical_filename('./a.py')
         sub_bpy = canonical_filename('./sub/b.py')