MDN Web Docs

Syntax

js

Response.error()

Parameters

None.

Return value

A Response object.

Examples

Returning a network error from a service worker

Suppose a web app has a service worker, which contains the following fetch event handler:

js

// service-worker.js
self.addEventListener("fetch", (event) => {
  const url = new URL(event.request.url);
  if (url.pathname === "/salamander.jpg") {
    event.respondWith(Response.error());
  }
});

With this service worker, all fetch requests from the app will pass through the service worker to the network, except for requests to fetch "salamander.jpg", which will reject. This means that the following main thread code would throw an error, and the catch handler will run.

js

// main.js
const image = document.querySelector("#image");
try {
  const response = await fetch("salamander.jpg");
  const blob = await response.blob();
  const objectURL = URL.createObjectURL(blob);
  image.src = objectURL;
} catch (e) {
  console.error(e);
}

Specifications

Specification
Fetch
# ref-for-dom-response-error①

Browser compatibility

See also

Help improve MDN

Yes No

Learn how to contribute

This page was last modified on by MDN contributors.

Read the original on developer.mozilla.org ↗