Class ExtensionManager

src/controller/extension-manager.ts:11–105

type ExtensionManagerData = Record<string, {dirPath: string}>;

export class ExtensionManager extends ConfigStoreItem {
  onAddExtension: Signal<(extension: Extension) => void> = new Signal();
  onRemoveExtension: Signal<(extension: Extension) => void> = new Signal();

  #extensions: Record<string, Extension> = {};

  constructor() {
    super();
    const sourceRootDir = path.resolve(__dirname, '..', '..');
    const exportsDir = path.resolve(__dirname, '..', 'exports');
    // Override how Node searches modules.
    const nodeModulePaths = Module['_nodeModulePaths'];
    Module['_nodeModulePaths'] = function(p) {
      const nodeModulesIndex = p.indexOf('node_modules');
      const fromNodeModule = nodeModulesIndex > -1 && nodeModulesIndex > sourceRootDir.length;
      const fromInternal = p.startsWith(sourceRootDir + path.sep);
      const paths = nodeModulePaths.call(this, p)
        .filter(mp => {
          if (fromInternal) {
            // Avoid using modules from outside the app bundle.
            if (!mp.startsWith(sourceRootDir))
              return false;
          }
          return true;
        });
      // Make it possible to do require('chie') when request does not come from
      // a npm module.
      if (!fromNodeModule) {
        // For extensions the exportsDir is preferred, while for inside app
        // bundle it is used as last resort. This is to make require('gui') use
        // the actual module inside app bundle, and use the fake one in the
        // extensions.
        if (fromInternal)
          paths.push(exportsDir);
        else
          paths.unshift(exportsDir);
      }
      return paths;
    };
  }

  deserialize(data: ExtensionManagerData) {
    this.activateBuiltinExtensions();
    for (const name in data)
      this.registerExternalExtension(data[name].dirPath);
  }

  serialize() {
    const data: ExtensionManagerData = {};
    for (const name in this.#extensions)
      data[name] = {dirPath: this.#extensions[name].dirPath};
    return data;
  }

  // Load builtin extensions.
  activateBuiltinExtensions() {
    const extensionsDir = path.join(__dirname, '..', 'extensions');
    const extensions = fs.readdirSync(extensionsDir);