Getting rollup to ignore the vm module

[Twipped]

I ran into a problem trying to use this on the web, because rollup just absolutely insisted that it had to require the vm module, even tho the code doesn't use it.

The way I finally solved it was by creating an entry in rollup-plugin-alias to redirect the vm module to use a local null.js module that just exports a default of null.

const alias = require('@rollup/plugin-alias');
const plugins = [
  alias({
    entries: [
      { find: 'vm', replacement: require.resolve('./lib/null') },
    ],
  }),
]

Figured I would pass this along for anyone else who struggles with this after me.

[brettz9]

@Twipped: Thank you for sharing this... But do you have a config you can point me to which wasn't working--i.e., when you weren't using the alias plugin? Were you using the node-resolve and commonjs plugins? Also how you were invoking the config, e.g., the command line arguments used?

[Twipped]

Here's the original config, minus any project specific bits.

const alias = require('@rollup/plugin-alias');
const commonjs = require('@rollup/plugin-commonjs');
const nodeResolve = require('@rollup/plugin-node-resolve');
const replace = require('@rollup/plugin-replace');
const babel = require('rollup-plugin-babel');

module.exports = exports = {
  input: 'src/renderer.jsx',
  output: [
    {
      dir: 'dist',
      format: 'esm',
      sourcemap: true,
      entryFileNames: 'index.js',
    },
  ],
  manualChunks: { vendor: [
    'lodash',
    'preact',
    'preact/compat/src/PureComponent.js',
    'mobx',
    'mobx-preact',
    'prop-types',
    'core-js',
    'core-js-pure',
  ] },
  plugins: [
    alias({
      entries: [
        { find: 'react', replacement: 'preact/compat' },
        { find: 'react-dom', replacement: 'preact/compat' },
        { find: 'uuid', replacement: require.resolve('uuid/dist/esm-browser') },
        { find: 'pure-component', replacement: require.resolve('preact/compat/src/PureComponent.js') },
      ],
    }),
    replace({
      'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV || 'development'),
      'isProduction': process.env.NODE_ENV === 'production',
    }),
    babel({
      exclude: 'node_modules/**',
    }),
    nodeResolve(),
    commonjs({
      include: 'node_modules/**',
      sourceMap: false,
    }),
  ],
  watch: {
    exclude: 'node_modules/**',
  },
};

This is the babel config:

module.exports = exports = {
  plugins: [
    [ '@babel/plugin-proposal-object-rest-spread', { loose: true, useBuiltIns: true } ],
    [ "@babel/plugin-proposal-decorators", { legacy: true } ],
    [ "@babel/plugin-proposal-class-properties", { loose: true } ],
  ],
  presets: [
    [ "@babel/preset-env", {
      useBuiltIns: "usage",
      corejs: { version: 3, shippedProposals: true },
    } ],
    "preact",
  ],
};

And finally the browserslist config:

last 2 Chrome versions
last 2 Safari versions
last 2 Firefox versions

[brettz9]

Thank you. I think given the complexity here, without a minimal reproducible repo including the input file, etc., it will take more effort than it may be worth to identify the problem. I don't know if it could be because Babel is run before the CommonJS or some other reason, but I haven't been able to replicate in a simpler config. So thank you for the information, but unless you want to go to the trouble of setting up a repo to replicate, I think we can leave it here with the info provided. Thanks!

[Twipped]

Yeah, considering that you're clearly not having the problem with your own builds, I knew it had to be something specific in my setup. That's why I didn't suggest that it needed fixing. I just wanted to leave this here to give some people breadcrumbs incase they encounter the same issue.

[brettz9]

Sure, understood. I tried tweaking it a little, like adding node_modules to the CJS plugin, but that wasn't enough to trigger it. Thanks again!