Added guard against HTMLElement in callSubscriber

[netsgnut]

Hi!

Thank you for the library! We are using v7.0.0 in one of the Next.js projects recently.

In one of the few instances that we are using this library, we are providing a

export default function AComponent(): JSX.Element {
  const ref = useRef<HTMLDivElement>(null);
  useResizeObserver<HTMLDivElement>({
    ref,
    onResize: ({ width }) => {
      // Do something here
    },
  });
  return (
    <div ref={ref}>{/* snip */}</div>
  );
}

However when we try to build it with next build, there will be a ReferenceError: HTMLElement is not defined.

ReferenceError: HTMLElement is not defined
    at useResolvedElement (node_modules/use-resize-observer/dist/bundle.cjs.js:54:23)
    at useResizeObserver (node_modules/use-resize-observer/dist/bundle.cjs.js:113:21)

...which I believe is caused by the HTMLElement being referenced in the server-side, when it is trying to resolve the element.

Admittedly I am not sure if we are actually abusing/misusing the library, or if the patch is merely hiding some bugs/issues lying deeper within the logic, since in another component that uses the ref from the library (just like what README says):

export default function BComponent(): JSX.Element {
  const { ref } = useResizeObserver<HTMLDivElement>({
    onResize: ({ width }) => {
      // Do something here
    },
  });
  return (
    <div ref={ref}>{/* snip */}</div>
  );
}

...does not result in such error.

What do you think?

[ZeeCoder]

@netsgnut this syntax only works when you use TypeScript. Maybe that's the issue? 🤔

[netsgnut]

Thank you for the swift response, @ZeeCoder ! While the code above is certainly TypeScript, I guess it is not really the reason here. 🤔

I have set up a super minimal repo demonstrating this potential issue. I have used npx create-next-app without using the TypeScript preset, and on my machine (Linux x64, node v14.16.0), it would reproduce the ReferenceError: HTMLElement is not defined.

[shobhitsharma]

@ZeeCoder I can confirm this throws for us too. Unfortunately have to rewrite this only my own instead of including this package to solve it.

[ZeeCoder]

I get the issue now, seems like Next.js is using js-dom for SSR, which does not include the HTMLElement global.
I do have a test for SSR, but that uses react-dom/server.

I'll need to refactor that test to replicate the issue before a fix is applied.

Thanks for flagging. 🙏

[oleg-slapdash]

@ZeeCoder @netsgnut Here is a repro, you need to use ForwardRef to get into this issue:
node test.js
test.js:

const React = require("react");
const ReactDOMServer = require("react-dom/server");
const useResizeObserver = require("use-resize-observer");

const ForwardRef = React.forwardRef(function (props, ref) {
  return React.createElement(
    "div",
    { style: { width: 100, height: 200 } },
    `${width}x${height}`
  );
});

function Test() {
  const ref = React.useRef(null);
  useResizeObserver({
    ref: ref,
  });
  return React.createElement(ForwardRef, { ref });
}

ReactDOMServer.renderToString(React.createElement(Test));

node -v
v15.1.0

% node test.js
/top-secret-project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3392
            throw err;
            ^

ReferenceError: HTMLElement is not defined
    at useResolvedElement (/top-secret-project/node_modules/use-resize-observer/dist/bundle.cjs.js:54:49)
    at useResizeObserver (/top-secret-project/node_modules/use-resize-observer/dist/bundle.cjs.js:113:21)
    at Test (/top-secret-project/packages/client/src/test.js:16:3)
    at processChild (/top-secret-project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3043:14)
    at resolve (/top-secret-project/node_modules/react-dom/cjs/react-dom-server.node.development.js:2960:5)
    at ReactDOMServerRenderer.render (/top-secret-project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3435:22)
    at ReactDOMServerRenderer.read (/top-secret-project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3373:29)
    at Object.renderToString (/top-secret-project/node_modules/react-dom/cjs/react-dom-server.node.development.js:3988:27)
    at Object.<anonymous> (/top-secret-project/packages/client/src/test.js:22:16)
    at Module._compile (node:internal/modules/cjs/loader:1083:30)
% node -v

[urish]

I can confirm the changes from this pull request fix the issue for me (also using Next.js SSR)

[ZeeCoder]

This is now fixed in 7.0.1! 🎉

The related commit in case anyone is interested in the final solution: 599cace

Thanks for everyone involved in this issue, your contributions helped and somewhat guided the final solution. 🙏

[urish]

Thank you!