index.js

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

// This Webpack plugin ensures `npm install <library>` forces a project rebuild.
// We’re not sure why this isn't Webpack's default behavior.
// See https://github.com/facebookincubator/create-react-app/issues/186.

'use strict';

class WatchMissingNodeModulesPlugin {
  constructor(nodeModulesPath) {
    this.nodeModulesPath = nodeModulesPath;
  }

  apply(compiler) {
    compiler.hooks.emit.tapAsync(
      'WatchMissingNodeModulesPlugin',
      (compilation, callback) => {
        const nodeModulesPath = this.nodeModulesPath;
        // If any missing files are expected to appear in node_modules...
        if (Array.from(compilation.missingDependencies).some(file => file.indexOf(nodeModulesPath) !== -1)) {
          // ...tell webpack to watch node_modules recursively until they appear.
          compilation.contextDependencies.push(nodeModulesPath);
        }

        if (typeof callback === 'function') {
          callback();
        }
      }
    );
  }
}

module.exports = WatchMissingNodeModulesPlugin;