ReadableStream.cancel()

The cancel() method of the ReadableStream interface returns a Promise that resolves when the stream is canceled.

Cancel is used when you've completely finished with the stream and don't need any more data from it, even if there are chunks enqueued waiting to be read. That data is lost after cancel is called, and the stream is not readable any more. To read those chunks still and not completely get rid of the stream, you'd use ReadableStreamDefaultController.close().

Syntax

cancel()
cancel(reason)

Parameters

• reason optional
  • : A human-readable reason for the cancellation. The underlying source may or may not use it.

Return value

A Promise, which fulfills with the value given in the reason parameter.

Exceptions

• TypeError
  • : The stream you are trying to cancel is not a ReadableStream, or it is locked.