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VirtualModulesPlugin

Rspack only

The rspack.experiments.VirtualModulesPlugin is a Rust port of the webpack-virtual-modules plugin. It's deeply integrated with Rspack to deliver the same functionality with enhanced performance.

Usage

Basic usage

You can pass virtual modules to the constructor when creating a new VirtualModulesPlugin instance:

new rspack.experiments.VirtualModulesPlugin(modules?: Record<string, string>)

Parameters:

  • modules (optional): An object where keys are file paths and values are file contents.
rspack.config.js
const rspack = require('@rspack/core');

module.exports = {
  plugins: [
    new rspack.experiments.VirtualModulesPlugin({
      'src/generated/config.js': 'export default { version: "1.0.0" };',
      'src/generated/constants.js': `
        export const API_URL = "${process.env.API_URL || 'http://localhost:3000'}";
        export const DEBUG = ${process.env.NODE_ENV !== 'production'};
      `,
    }),
  ],
};

Dynamic module creation

You can dynamically create or modify virtual modules using the writeModule method:

writeModule(filePath: string, contents: string): void

Parameters:

  • filePath: The virtual file path relative to compiler.context
  • contents: The content of the virtual file
rspack.config.js
const rspack = require('@rspack/core');

const virtualModulesPlugin = new rspack.experiments.VirtualModulesPlugin();

module.exports = {
  plugins: [
    virtualModulesPlugin,
    {
      apply(compiler) {
        compiler.hooks.beforeCompile.tap('MyPlugin', () => {
          // Dynamically create modules
          const moduleContent = generateSomeContent();
          virtualModulesPlugin.writeModule('src/dynamic.js', moduleContent);
        });
      },
    },
  ],
};