webpack-target-webextension

WebExtension Plugin for Webpack 5. Supports code-splitting and Hot Module Reload.

Looking for webpack 4 support? Please install 0.2.1. Document for 0.2.1.

Installation

Choose the package manager you're using.

yarn add -D webpack-target-webextension
npm install -D webpack-target-webextension
pnpm install -D webpack-target-webextension

Features & How to configure

Code splitting

Content script

You need to configure at least one of the following to make code-splitting work for the content script.

1. dynamic import()
   • Requires Firefox 89 and Chrome 63(?).
   • Set output.environment.dynamicImport to true in your webpack config.
   • You must set web_accessible_resources to your JS files in your manifest.json.
   • ⚠ Normal web sites can access your resources in web_accessible_resources too.
   • Example: ./examples/code-splitting-way-1
2. via chrome.tabs.executeScript (Manifest V2)
   • Requires options.background to be configured and options.background.classicLoader is not false (defaults to true).
   • Example: ./examples/code-splitting-way-2
3. via chrome.scripting.executeScript (Manifest V3)
   • It will fallback to method 2 when there is no chrome.scripting.
   • Requires "scripting" permission in the manifest.json.
   • Requires options.background to be configured and options.background.classicLoader is not false (defaults to true).
   • Example: ./examples/code-splitting-way-3

Background worker (Manifest V3)

⚠ Not working with "background.type" set to "module" (native ES Module service worker). Tracking issue: #24

Support code-splitting out of the box, but it will load all chunks (without executing them).

See https://bugs.chromium.org/p/chromium/issues/detail?id=1198822 for the reason.

This fix can be turned off by setting options.background.eagerChunkLoading to false.

Example: ./examples/code-splitting-way-3

Hot Module Reload

⚠ It's not possible to support HMR for Manifest V3 background worker before this bug is fixed. https://bugs.chromium.org/p/chromium/issues/detail?id=1198822

⚠ In content script of Firefox, the HMR WebSocket server might be blocked by the Content Security Policy and prevent the reset of the code to be executed. Please disable hmr if you encountered this problem.

This plugin works with Hot Module Reload. Please set devServer.hot to "only" (or true) to enable it. It will modify your devServer configuration to adapt to the Web Extension environment. To disable this behavior, set options.hmrConfig to false.

You need to add *.json to your web_accessible_resources in order to download HMR manifest.

Example: Manifest V2 ./examples/hmr-mv2

Example: Manifest V3 ./examples/hmr-mv3

Example: Draw UI in the content scripts with React and get React HRM. ./examples/react-hmr

Source map

To use source map based on eval, you must use Manifest V2 and have script-src 'self' 'unsafe-eval'; in your CSP (content security policy).

⚠ DO NOT add unsafe-eval to your CSP in production mode!

Public path

This plugin supports the public path when output.path is set.

Options

options.background

Example:

new WebExtensionPlugin({
  background: { pageEntry: 'background', serviceWorkerEntry: 'background-worker' },
})

export interface BackgroundOptions {
  /** Undocumented. */
  noWarningDynamicEntry?: boolean
  /**
   * The entry point of the background scripts
   * in your webpack config.
   * @deprecated
   * Use pageEntry and serviceWorkerEntry instead.
   */
  entry?: string
  /**
   * Using Manifest V2 or V3.
   *
   * If using Manifest V3,
   * the entry you provided will be packed as a Worker.
   *
   * @defaultValue 2
   * @deprecated
   */
  manifest?: 2 | 3
  /**
   * The entry point of the background page.
   */
  pageEntry?: string
  /**
   * The entry point of the service worker.
   */
  serviceWorkerEntry?: string
  /**
   * Only affects in Manifest V3.
   *
   * Load all chunks at the beginning
   * to workaround the chrome bug
   * https://bugs.chromium.org/p/chromium/issues/detail?id=1198822.
   *
   * @defaultValue true
   */
  eagerChunkLoading?: boolean
  /**
   * Add the support code that use
   * `chrome.scripting.executeScript` (MV3) or
   * `chrome.tabs.executeScript` (MV2) when
   * dynamic import does not work for chunk loading
   * in the content script.
   * @defaultValue true
   */
  classicLoader?: boolean
}

options.hmrConfig

Default value: true

Example:

new WebExtensionPlugin({ hmrConfig: false })

options.weakRuntimeCheck

If you need to use this plugin with mini-css-extract-plugin or HtmlWebpackPlugin, please enable this option.