Guide to jest and @swc/jest


Loading subresources

By default, jsdom will not load any subresources such as scripts, stylesheets, images, or iframes. If you'd like jsdom to load such resources, you can pass the resources: "usable" option, which will load all usable resources. Those are:

  • Frames and iframes, via <frame> and <iframe>
  • Stylesheets, via <link rel="stylesheet">
  • Scripts, via <script>, but only if runScripts: "dangerously" is also set
  • Images, via <img>, but only if the canvas npm package is also installed (see "Canvas Support" below)

When attempting to load resources, recall that the default value for the url option is "about:blank", which means that any resources included via relative URLs will fail to load. (The result of trying to parse the URL /something against the URL about:blank is an error.) So, you'll likely want to set a non-default value for the url option in those cases, or use one of the convenience APIs that do so automatically.