Refresh access token when using a very old short-lived access token with unknown expiration (dropbox#352)

Brent1LT · Brent Bumann · web-flow · commit 7cdab3c1a555 · 2021-05-07T15:20:14.000-07:00
Co-authored-by: Brent Bumann &lt;bbumann@dropbox.com&gt;
diff --git a/dropbox/dropbox_client.py b/dropbox/dropbox_client.py
@@ -358,9 +358,10 @@ def check_and_refresh_access_token(self):
         :return:
         """
         can_refresh = self._oauth2_refresh_token and self._app_key
-        needs_refresh = self._oauth2_access_token_expiration and \
-            (datetime.utcnow() + timedelta(seconds=TOKEN_EXPIRATION_BUFFER)) >= \
-            self._oauth2_access_token_expiration
+        needs_refresh = self._oauth2_refresh_token and \
+            (not self._oauth2_access_token_expiration or
+            (datetime.utcnow() + timedelta(seconds=TOKEN_EXPIRATION_BUFFER)) >=
+            self._oauth2_access_token_expiration)
         needs_token = not self._oauth2_access_token
         if (needs_refresh or needs_token) and can_refresh:
             self.refresh_access_token(scope=self._scope)
diff --git a/test/unit/test_dropbox_unit.py b/test/unit/test_dropbox_unit.py
@@ -345,6 +345,18 @@ def test_check_refresh_with_only_refresh(self, session_instance):
         dbx.check_and_refresh_access_token()
         assert session_instance.post.call_count == 1
 
+    def test_refresh_token_with_no_expiration(self, session_instance):
+        # Test refresh token is refreshed when not given expiration
+        dbx = Dropbox(oauth2_access_token=ACCESS_TOKEN,
+                      oauth2_refresh_token=REFRESH_TOKEN,
+                      oauth2_access_token_expiration=None,
+                      app_key=APP_KEY,
+                      app_secret=APP_SECRET,
+                      session=session_instance)
+        dbx.check_and_refresh_access_token()
+        assert session_instance.post.call_count == 1
+        assert dbx._oauth2_access_token_expiration
+
     def test_check_refresh_with_invalid_grant(self, invalid_grant_session_instance):
         dbx = Dropbox(oauth2_refresh_token=REFRESH_TOKEN,
                       app_key=APP_KEY,
