🐛 BUG: globalThis.XMLHttpRequest is not a constructor

[ggvbo]

What version of Wrangler are you using?

2.0.3

What operating system are you using?

Windows

Describe the Bug

Using wrangler dev results in this:

 {
    text: 'Received a bad response from the API',
    notes: [
      {
        text: 'Uncaught TypeError: globalThis.XMLHttpRequest is not a constructor\n' +
          '  at line 0\n' +
          ' [code: 10021]'
      }
    ],
    location: undefined,
    kind: 'error',
    code: 10021
  }

I'm running an TypeScript application compiled into JavaScript and using that w/node-compatibility, this is what my wrangler.toml looks like:

name = "onemiwrap"
compatibility_date = "2022-05-13"
main = "./dist/index.js"
node_compat = true

Is this expected behaviour, and if it isn't, what can I do to work around it?

[threepointone]

Here's what I think is happening. Currently for node_compat, we use polyfills that were originally meant for the browser. Specifically, the polyfills for http use XMLHTTPRequest for polyfilling http.get(), etc. We want to replace this with a better polyfill using fetch, which we'll do in the future. However, we've commonly seen this error for folks who already are trying to polyfill fetch itself. My guess here is that you have a polyfill for fetch (maybe isomorphic-fetch, node-fetch, or something similar). Look in your package.json and you might see it. You don't need these polyfills in Workers, since we natively provide fetch. Removing this should make this specific error go away.

Happy to help further if you can provide a small repo that reproduces the error.

[abizek]

Facing the same issue with wrangler@2.0.6 on macOS. I am trying to connect to mongoDB and fetch a document. Made a example worker repo that reproduces the error.

I also found an issue that seems related - ionic-team/rollup-plugin-node-polyfills#31. But I'm not sure if it will help.

[petebacondarwin]

Thanks for the reproduction @abizek - that accurately shows the problem which is that mongodb (or one of its dependencies) uses the built-in node:http or node:https modules, and the polyfill library that we are using converts this to use XmlHttpRequest under the hood. This is what @threepointone is referring to above.

[petebacondarwin]

Marking this an enhancement as thenode-compat explicitly calls out that it is not a complete solution.

[chenthillrulz]

Facing the similar issue while trying to use cassandra driver,
service core:user:my-app: Uncaught TypeError: globalThis.XMLHttpRequest is not a constructor
at index.js:22225:11 in checkTypeSupport
at index.js:22247:38 in node_modules/rollup-plugin-node-polyfills/polyfills/http-lib/capability.js
at index.js:15:56 in __init
at index.js:22512:5 in node_modules/rollup-plugin-node-polyfills/polyfills/http-lib/request.js
at index.js:15:56 in __init
at index.js:23499:5 in node-modules-polyfills:https
at index.js:15:56 in __init
at index.js:23604:21 in node-modules-polyfills-commonjs:https
at index.js:18:50 in __require2

[jonbeckman]

Hey @petebacondarwin, any update on this?

[petebacondarwin]

No update right now. The solution will be for the http polyfill to use fetch rather than XHR.
It might be that we could create our own polyfill if the upstream rollup-plugin-node-polyfill library does not get updated.

[NorbertBodziony]

Also got hit with it. It would be great to have some workaround.

[penalosa]

I’m going to close this issue for now, since this is a limitation of the node_compat system. Going forward, the Workers runtime is working on adding support for more Node.JS builtins, including possibly the node:http module.

In the meantime, the best solution for now is to include your own polyfills of Node.JS builtins like http.