xpm/node_modules/wscript-avoider/lib/wscript-avoider.js

The xPack project manager command line tool

/*
 * This file is part of the xPack distribution
 *   (http://xpack.github.io).
 * Copyright (c) 2015 Liviu Ionescu.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

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const assert = require('assert')

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/**
 * @brief Static class to avoid running on Windows Script Host.
 *
 * @details
 * To use this class:
 *
 *   const WscriptAvoider = require('wscript-avoider').WscriptAvoider
 *
 *   WscriptAvoider.quitIfWscript(appName)
 */
// export
class WscriptAvoider {
  /**
   * @brief Avoid running on Windows Script Host.
   * @param app_name The application name; used only to display a
   *  meaningfull error message.
   * @return undefined, when not running on WScript.
   *
   * @details
   * Check if a global `WScript` object exists. If so, this is a bad sign,
   * it means the script was started by Windows Script Host,
   * instead of Node.js, and there is not much to do then quit abruptly.
   *
   * In normal conditions the `WScript` object does not exist,
   * and this function returns.
   */
  static quitIfWscript (appName) {
    /* global WScript */
    if (typeof WScript !== 'undefined') {
      WScript.echo(appName + ' does not work when run\n' +
        'with the Windows Scripting Host\n\n' +
        '"cd" to a different folder,\n' + 'or type "' +
        appName + '.cmd <args>",\n' + 'or type "node ' +
        appName + ' <args>".')
      WScript.quit(1)
    }
  }

  /**
   * @brief Dummy constructor, to catch unsupported instantiations.
   */
  constructor () {
    assert(false, 'WscriptAvoider is a static class, instantiation not allowed.')
  }
}

// ----------------------------------------------------------------------------
// Node.js specific export definitions.

// By default, `module.exports = {}`.
// The static class is added as a property of this object.
module.exports.WscriptAvoider = WscriptAvoider

// In ES6, it would be:
// export class WscriptAvoider { ... }
// ...
// import { WscriptAvoider } from 'wscript-avoider.js'

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