- propagate-common-errors #!optional booleanparameter
A lot of errors that occur in the lifecycle of a websocket connection are more-or-less expected and it often is not interesting to receive and deal with these errors. The default is to correctly close the connection when an error occurs with the required opcode but the error is then not signaled to the user. The default is #f. Set to #t to receive all errors.
All websocket specific errors are covered by this. The only error you may receive if this is #f is of type websocket and unexpected-error if something goes terribly wrong with the implementation and usually means there is a bug in the implementation. This does not affect errors that are caused by user code, they will always be passed on but the websocket will be properly with an error code of 1011 (unexpected-error).
Note that this parameter is only relevant when using with-websocket or with-concurrent-websocket. If you don't use one of those then all errors will be propagated.