CONSOLE MESSAGE: TypeError: undefined is not an object (evaluating 'e.error')
CONSOLE MESSAGE: Unhandled Promise Rejection: undefined

Harness Error (FAIL), message = TypeError: undefined is not an object (evaluating 'e.error')

PASS error argument is given to start method 
PASS Underlying sink's write won't be called until start finishes 
PASS Underlying sink's close won't be called until start finishes 
PASS Fulfillment value of ws.close() call must be undefined even if the underlying sink returns a non-undefined value 
PASS Underlying sink's write or close are never invoked if start throws 
PASS Underlying sink's write or close are never invoked if the promise returned by start is rejected 
PASS WritableStream can be constructed with no arguments 
PASS WritableStream instances have the correct methods and properties 
PASS WritableStream with simple input, processed asynchronously 
PASS WritableStream with simple input, processed synchronously 
PASS WritableStream is writable and ready fulfills immediately if the strategy does not apply backpressure 
PASS Fulfillment value of ws.write() call must be undefined even if the underlying sink returns a non-undefined value