process and Buffer not defined when using Webpack 5

[federicochiesa]

As the title says, when I try to use MQTT.js with Webpack 5 I get these errors and I can't run my code.

I installed Buffer using npm install buffer but that didn't change a thing.

[ErlendAHall]

This happens because Webpack 5 no longer automatically bundles core node modules, or they might be browser polyfills (correct me if Im wrong).

• First off, install buffer and process.

• Then, if you have access to the webpack config, add these under resolve.fallback
  
  Basically, you tell webpack if it encounters some unresolved modules amongst your dependencies, then here is a list of possible fallbacks.

• Finally, we need to make sure the browser won't reference globalThis.process or globalThis.Buffer once you execute in browser. These modules comes from the Node namespace.

• webpack.ProvidePlugin can be used to create an"alias" so that webpack will pop into node_modules and include buffer and process into the bundle.

[federicochiesa]

Thanks! That fixed it.

[Pavanct]

Any thoughts on how to fix this in React?

[vkiranmaniya]

Any thoughts on how to fix this in React?

Are you using CRA?