MQTT.js import error: This browser lacks typed array (Uint8Array) support which is required by buffer v5.x. Use buffer v4.x if you require old browser support.

[vmasdani]

hi. I tried importing MQTT.js with a single js file mqtt.min.js like this, and tried to run and got this errror.

This is the code.

Any idea or workaround to fix this? This is my deno version

[josephrocca]

I'm guessing this is because MQTT.js contains a browserified version of Node.js's Buffer, and that package tries to change prototypes using __proto__. This doesn't work because, unlike browsers, Deno doesn't allow __proto__ to be overwritten (relevant issue). One way to fix this (as mentioned here) is to replace all instances of obj.__proto__ = newPrototype with Object.setPrototypeOf(obj, newPrototype).

But actually, it looks like the latest version of browserify's Buffer uses setPrototypeOf instead of __proto__, so you may just be able to ask the maintainer of https://github.com/mqttjs/MQTT.js to re-browserify the package and publish a new version.

[benatkin]

I'm getting this with babel-standalone:

build.js

const example = `
import { createSignal, onCleanup } from "solid-js";
import { render } from "solid-js/web";

const CountingComponent = () => {
	const [count, setCount] = createSignal(0);
	const interval = setInterval(
		() => setCount(c => c + 1),
		1000
	);
	onCleanup(() => clearInterval(interval));
	return <div>Count value is {count()}</div>;
};

render(() => <CountingComponent />, document.getElementById("app"));
`;

import Babel from "https://esm.sh/@babel/standalone";
import solid from "https://esm.sh/babel-preset-solid";
Babel.registerPreset("solid", solid());
console.log(Babel.transform(example, {presets: ["solid"]}).code);

❯ deno run --allow-env=BABEL_TYPES_8_BREAKING build.js
This browser lacks typed array (Uint8Array) support which is required by `buffer` v5.x. Use `buffer` v4.x if you require old browser support.
import { template as _$template } from "solid-js/web";
import { createComponent as _$createComponent } from "solid-js/web";
import { insert as _$insert } from "solid-js/web";

const _tmpl$ = _$template(`<div>Count value is </div>`, 2);

import { createSignal, onCleanup } from "solid-js";
import { render } from "solid-js/web";

const CountingComponent = () => {
  const [count, setCount] = createSignal(0);
  const interval = setInterval(() => setCount(c => c + 1), 1000);
  onCleanup(() => clearInterval(interval));
  return (() => {
    const _el$ = _tmpl$.cloneNode(true),
          _el$2 = _el$.firstChild;

    _$insert(_el$, count, null);

    return _el$;
  })();
};

render(() => _$createComponent(CountingComponent, {}), document.getElementById("app"));