This function customizes error handling in the REPL. It receives the thrown exception as its first argument and must return one of the following values synchronously:
'print'to print the error to the output stream (default behavior).'ignore'to skip all remaining error handling.'unhandled'to treat the exception as fully unhandled. In this case, the error will be passed to process-wide exception handlers, such as the'uncaughtException'event. The'unhandled'value may or may not be desirable in situations where theREPLServerinstance has been closed, depending on the particular use case.