Experiments

experiments

boolean: false

experiments option was introduced in webpack 5 to empower users with the ability to activate and try out experimental features.

Available options:

• syncWebAssembly: Support the old WebAssembly like in webpack 4
• asyncWebAssembly: Support the new WebAssembly according to the updated specification, it makes a WebAssembly module an async module
• topLevelAwait: Support the Top Level Await Stage 3 proposal, it makes the module an async module when await is used on the top-level
• outputModule: enables the use of output.module configuration option and sets it to true. Enables the use of output.libraryTarget as 'module' and sets it to 'module'.
• layers: Enable module and chunk layers.

webpack.config.js

module.exports = {
  //...
  experiments: {
    outputModule: true,
    syncWebAssembly: true,
    topLevelAwait: true,
    asyncWebAssembly: true,
    layers: true,
    lazyCompilation: true,
  },
};

experiments.lazyCompilation

Compile entrypoints and dynamic imports only when they are accessed.

• Type
  • boolean
  • object

    {
      // define a custom backend
      backend?: ((
        compiler: webpack.Compiler,
        client: string,
        callback: (err?: Error, api?: any) => void
      ) => void)
      | ((
          compiler: webpack.Compiler,
          client: string
        ) => Promise<any>),
      client?: string, // define a custom client
      entries?: boolean // enable lazy compilation for entries
    }

• Available: 5.17.0+
• Example:

  module.exports = {
    // …
    experiments: {
      lazyCompilation: true,
    },
  };

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Contributors

EugeneHlushko wizardofhogwarts chenxsan anshumanv