try to fix progess bar test in a parallel pytest environment

dvc/progress.py

@@ -38,6 +38,12 @@ class Progress(object):
         self._print(line, end="")
         sys.stdout.flush()
 
+    def reset(self):
+        with self._lock:
+            self._n_total = 0
+            self._n_finished = 0
+            self._line = None
+
     def refresh(self, line=None):
         """Refreshes progress bar."""
         # Just go away if it is locked. Will update next time

tests/unit/test_progress.py

@@ -7,7 +7,10 @@ from dvc.progress import progress, progress_aware
 class TestProgressAware(TestCase):
     @mock.patch("sys.stdout.isatty", return_value=True)
     @mock.patch("dvc.progress.Progress._print")
-    def test(self, mock_print, mock_isatty):
+    def test(self, mock_print, _):
+        # progress is a global object, can be shared between tests when
+        # run in multi-threading environment with pytest
+        progress.reset()
         function = progress_aware(lambda: None)
 
         function()