I managed to get this to work with some help from the Webpack team. Using the following webpack configuration as recommended by the antlr4 documentation is no longer supported.

Does not work

{
  node: {
    fs: 'empty',
    module: 'empty',
    net: 'empty'
  }
}

Working configuration

{
  resolve: {
    fallback: {
      fs: false
    }
  }
}

With this, I was able to get my JavaScript parser working.

Please note that there is an ongoing effort to update antlr4 to generate ES6 based code. This configuration may not be necessary in the future.

Interesting enough, I get in case of path (but not with file) the following message, more clear of webpack CLI:

BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.

If you want to include a polyfill, you need to:
    - add a fallback 'resolve.fallback: { "path": require.resolve("path-browserify") }'
    - install 'path-browserify'
If you don't want to include a polyfill, you can use an empty module like this:
    resolve.fallback: { "path": false }

However it seems to me this info should also be found here, and removed the statement that any built-in module can be used as property there: https://webpack.js.org/configuration/node/#node

Exactly for rails webpacker, if you are using it, the solution should be a:

Inside any of config/webpack/*.js which uses the plain custom config (see https://github.com/rails/webpacker#webpack-configuration for more), just add the code resolving and removing the node property.

const { environment } = require('@rails/webpacker')

const customConfig = {
  resolve: {
    fallback: {
      dgram: false,
      fs: false,
      net: false,
      tls: false,
      child_process: false
    }
  }
};

environment.config.delete('node.dgram')
environment.config.delete('node.fs')
environment.config.delete('node.net')
environment.config.delete('node.tls')
environment.config.delete('node.child_process')

environment.config.merge(customConfig);

module.exports = environment

I have encountered with same issue while working with Next js, I have searched different solutions like webpack5: false or fs: false, but that didn't work for me.

config.node = {
  // fs: 'empty'
  global: true,
  __filename: true,
  __dirname: true,
}

this did work for me, because in webpack 3.0.0, the node option may be set to false to completely turn off the NodeStuffPlugin, as we are working in JS and specially in Next-JS which requires Node-JS, so we don't have to turn it off completely because while 'false' the Webpack wouldn't touch your '__filename' code and your '__dirname' code.

Any correction or guidance's will be appreciated, Thankyou

Next.js users:

module.exports = {
  webpack: (config, { isServer }) => {
    if (!isServer) {
      config.resolve.fallback.fs = false;
    }
    return config;
  },
}

Source

If someone is facing this error in Next JS, I found the solution by disabling webpack 5 which is set by default.

disable it by webpack5: false in next.config.js