@rollup/plugin-virtual

@rollup/plugin-virtual

🍣 A Rollup plugin which loads virtual modules from memory.

Requirements

This plugin requires an LTS Node version (v14.0.0+) and Rollup v1.20.0+.

Install

Using npm:

npm install @rollup/plugin-virtual --save-dev

Usage

Note. Use this plugin before any others such as node-resolve or commonjs, so they do not alter the output.

Suppose an entry file containing the snippet below exists at src/entry.js, and attempts to load batman and src/robin.js from memory:

// src/entry.js
import batman from 'batman';
import robin from './robin.js';

console.log(batman, robin);

Create a rollup.config.js configuration file and import the plugin:

import virtual from '@rollup/plugin-virtual';

export default {
  input: 'src/entry.js',
  // ...
  plugins: [
    virtual({
      batman: `export default 'na na na na na'`,
      'src/robin.js': `export default 'batmannnnn'`
    })
  ]
};

Then call rollup either via the CLI or the API.

Options

This plugin has no formal options. The lone parameter for this plugin is an Object containing properties that correspond to a String containing the virtual module's code.

Using the Plugin for Bundle Input

It's possible to use the plugin to specify an entry point for a bundle. To do so, implement a pattern simple to what is shown below:

import virtual from '@rollup/plugin-virtual';

export default {
  input: 'entry',
  // ...
  plugins: [
    virtual({
      entry: `
import batman from 'batcave';
console.log(batman);
`
    })
  ]
};

License

MIT

Similar packages

Other packages similar to @rollup/plugin-virtual

rollup-plugin-inject

rollup-plugin-inject allows you to inject variables or modules into your bundle. While it does not create virtual modules, it can be used to achieve similar results by injecting code into existing modules.

rollup-plugin-replace

rollup-plugin-replace allows you to replace strings in your code during the build process. It can be used to inject dynamic content or mock modules, similar to @rollup/plugin-virtual, but it operates by replacing existing code rather than creating new virtual modules.

rollup-plugin-alias

rollup-plugin-alias allows you to create aliases for module paths. While it does not create virtual modules, it can be used to redirect module imports to different files or modules, which can be useful for testing or injecting custom implementations.