The desiredSize
read-only property of the WritableStreamDefaultWriter
interface returns the desired size required to fill the stream's internal queue.
An integer. Note that this can be negative if the queue is over-full.
The value will be null
if the stream cannot be successfully written to (due to either being errored, or having an abort queued up), and zero if the stream is closed.
const writableStream = new WritableStream({
write(chunk) {
...
},
close() {
...
},
abort(err) {
...
}
}, queuingStrategy);
...
const writer = writableStream.getWriter();
...
let size = writer.desiredSize;