better handler API error parsing.

Possibly we encountered an error while parsing the API error JSON, like
connection closes early etc and the received JSON is invalid.

Better handle such scenario and build a valid error Dict to keep the
exception stack flow running and raise this message to the application.

Signed-off-by: Alexandre Lavigne <[email protected]>

gspread/exceptions.py

@@ -9,6 +9,7 @@
 from typing import Any, Mapping
 
 from requests import Response
+from requests.exceptions import JSONDecodeError
 
 
 class UnSupportedExportFormat(Exception):
@@ -40,7 +41,19 @@ class APIError(GSpreadException):
     such as when we attempt to retrieve things that don't exist."""
 
     def __init__(self, response: Response):
-        error = dict(response.json()["error"])
+        try:
+            error = response.json()["error"]
+        except JSONDecodeError:
+            # in case we failed to parse the error from the API
+            # build an empty error object to notify the caller
+            # and keep the exception raise flow running
+
+            error = {
+                "code": -1,
+                "message": "failed to parse API error",
+                "status": "invalid JSON",
+            }
+
         super().__init__(error)
         self.response: Response = response
         self.error: Mapping[str, Any] = error