handle exceptions which have no message

src/seedsigner/controller.py

@@ -309,7 +309,12 @@ def handle_exception(self, e) -> Destination:
  # So we extract the Exception type and trim off any "foo.bar." namespacing:
  last_line = traceback.format_exc().splitlines()[-1]
  exception_type = last_line.split(":")[0].split(".")[-1]
- exception_msg = last_line.split(":")[1]
+
+ # Extract the error message, if there is one
+ if ":" in last_line:
+ exception_msg = last_line.split(":")[1]
+ else:
+ exception_msg = ""
 
  # Scan for the last debugging line that includes a line number reference
  line_info = None

tests/test_controller.py

@@ -43,6 +43,48 @@ def test_singleton_get_instance_preserves_state(reset_controller):
  assert controller.unverified_address == "123abc"
 
 
+def test_handle_exception(reset_controller):
+ """ Handle exceptions that get caught by the controller """
+
+ def process_exception_asserting_valid_error(exception_type, exception_msg=None):
+ """
+ Exceptions caught by the controller are forwarded to the
+ UnhandledExceptionView with view_args["error"] being a list
+ of three strings, ie: [exception_type, line_info, exception_msg]
+ """
+ try:
+ if exception_msg:
+ raise exception_type(exception_msg)
+ else:
+ raise exception_type()
+ except Exception as e:
+ error = controller.handle_exception(e).view_args["error"]
+
+ # assert that error structure is valid
+ assert len(error) == 3
+ assert error[0] in str(exception_type)
+ assert type(error[1]) == str
+ if exception_msg:
+ assert exception_msg in error[2]
+ else:
+ assert error[2] == ""
+
+ # Initialize the controller
+ controller = Controller.get_instance()
+
+ exception_tests = [
+ # exceptions with an exception_msg
+ (Exception, "foo"),
+ (KeyError, "key not found"),
+ # exceptions without an exception_msg
+ (Exception, ""),
+ (Exception, None),
+ ]
+
+ for exception_type, exception_msg in exception_tests:
+ process_exception_asserting_valid_error(exception_type, exception_msg)
+
+
 def test_missing_settings_get_defaults(reset_controller):
  """ Should gracefully handle all missing fields from `settings.json` """