rollup-plugin-bundle-guard

A rollup plugin that makes sure you don't accidentally import something statically, which could have an effect on your bundle size.

How?

Tag files you want to be in the same group by adding a comment with the group name.

// rollup-plugin-bundle-guard: group=entry

If you attempt to statically import a file that is not in the same group, your build will fail with something like:

"entry.js" statically imports "load-me-dynamically.js" which is not allowed. Should it be in "entry"?

That's it!

More Detail

With strict mode disabled anything that is not assigned a group will default to the group named default, and anything is allowed to import something assigned to the default group.

Each module can only be assigned to a single group. You can however include additional groups that are allowed to import the module with the following comment:

// rollup-plugin-bundle-guard: allowedImportFrom=<group 1 name> <group 2 name> ...

This makes it possible for separate bundles to statically import shared dependencies.

Installation

npm install --save-dev rollup-plugin-bundle-guard

Usage

rollup.config.js

import rollupPluginBundleGuard from 'rollup-plugin-bundle-guard';

export default {
  input: 'main.js',
  plugins: [
    // default config
    // rollupPluginBundleGuard(),

    // all the options
    rollupPluginBundleGuard({
      // Defaults to `false`. If enabled, all imported modules must be assigned a group.
      // Otherwise anything without a group is assigned a group named `default`
      strictMode: false,
      modules: [
        // 'react' can be imported from both the `entry` and `default` group
        { allowedImportFrom: ['entry', 'default'], module: 'react' },
        // anything that contains the string 'somegroup' will be part of the 'someGroup' group
        { group: 'someGroup', module: /somegroup/ },
      ],
      // optional. The default (below) disables checking comments for anything in 'node_modules'
      comments: {
        pathPatterns: [ /node_modules/ ],
        isWhitelist: false
      }
    })
    // ...
  ],
  // ...
});

main.js

// rollup-plugin-bundle-guard: group=entry

import 'react'; // allowed because `entry` is allowed to import `react`
import './a.js'; // allowed because `./a.js` is also in `entry`
import './b.js'; // ERROR! not allowed because `./b.js` is not in `entry`

import('./b.js'); // allowed because it's a dynamic import

a.js

// rollup-plugin-bundle-guard: group=entry

console.log('In module a.');

b.js

// rollup-plugin-bundle-guard: group=group2

import './c.js'; // ERROR! c is in `default`, not `group2`

console.log('In module b.');

c.js

// in the default group
import './d.js';

console.log('In module c.');

d.js

// in the `default` group
import 'react'; // allowed because `default` is allowed to import `react`

import './a.js'; // allowed because in non strict mode `a.js` is allowing imports from `default`

console.log('In module d.');