Start using our own monkeypatch function for some things

jedi/common/utils.py

@@ -1,4 +1,5 @@
 import os
+from contextlib import contextmanager
 
 
 def traverse_parents(path, include_current=False):
@@ -10,3 +11,16 @@ def traverse_parents(path, include_current=False):
         yield path
         previous = path
         path = os.path.dirname(path)
+
+
+@contextmanager
+def monkeypatch(obj, attribute_name, new_value):
+    """
+    Like pytest's monkeypatch, but as a context manager.
+    """
+    old_value = getattr(obj, attribute_name)
+    try:
+        setattr(obj, attribute_name, new_value)
+        yield
+    finally:
+        setattr(obj, attribute_name, old_value)