fetch-network-interruption.js

/* To test, initiate the fetch() and interrupt your network conneciton
 * (e.g. turn off wireless). The originating ReadableStreamDefaultReader.read()
 * error is lost and unavailable to application's outermost Promise.reject catch()
 */
fetch('https://fetch-progress.anthum.com/10kbps/images/sunrise-baseline.jpg')
.then(response => {
  const reader = response.body.getReader();

  return new Response(
    new ReadableStream({
      start(controller) {
        read()
        function read() {
          reader.read().then(({done, value}) => {
            if (done) {
              controller.close();
              return;
            }

            controller.enqueue(value);
            read();
          }).catch(error => {
            console.error('error at read()', error);
            controller.error(error)
          })
        }
      }
    })
  )
})
.then(response => response.arrayBuffer())
.catch(error => console.error(error))