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Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Documentationbreadcrumb arrow Grafana k6breadcrumb arrow JavaScript APIbreadcrumb arrow k6/experimentalbreadcrumb arrow streamsbreadcrumb arrow ReadableStreamDefaultControllerbreadcrumb arrow error(reason)
Open source

error(reason)

The error() method of the ReadableStreamDefaultController makes any future interactions with the associated stream to error.

Parameters

NameTypeDescription
eanyThe error to return to any future interactions with the stream.

Exceptions

ExceptionDescription
TypeErrorThrown when the source object is not a ReadableStreamDefaultController.

Example

JavaScript 
import { ReadableStream } from 'k6/experimental/streams';
import { setTimeout } from 'k6/timers';

export default async function () {
  let currentNumber = 0;

  const stream = new ReadableStream({
    start(controller) {
      const fn = () => {
        if (currentNumber % 8 == 0) {
          // Error the stream when the number is divisible by 8
          controller.error('erroring the stream because we received a multiple of 8');
          return;
        }

        if (currentNumber < 10) {
          controller.enqueue(++currentNumber);
          setTimeout(fn, 1000);
          return;
        }

        controller.close();
      };
      setTimeout(fn, 1000);
    },
  });

  const reader = stream.getReader();

  while (true) {
    const { done, value } = await reader.read();
    if (done) break;
    console.log(`received number ${value} from stream`);
  }
}