hexo-generator/node_modules/warning/warning.js

/**
 * Copyright 2014-2015, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

'use strict';

/**
 * Similar to invariant but only logs a warning if the condition is not met.
 * This can be used to log issues in development environments in critical
 * paths. Removing the logging code for production environments will keep the
 * same logic and follow the same code paths.
 */

var __DEV__ = process.env.NODE_ENV !== 'production';

var warning = function() {};

if (__DEV__) {
  warning = function(condition, format, args) {
    var len = arguments.length;
    args = new Array(len > 2 ? len - 2 : 0);
    for (var key = 2; key < len; key++) {
      args[key - 2] = arguments[key];
    }
    if (format === undefined) {
      throw new Error(
        '`warning(condition, format, ...args)` requires a warning ' +
        'message argument'
      );
    }

    if (format.length < 10 || (/^[s\W]*$/).test(format)) {
      throw new Error(
        'The warning format should be able to uniquely identify this ' +
        'warning. Please, use a more descriptive format than: ' + format
      );
    }

    if (!condition) {
      var argIndex = 0;
      var message = 'Warning: ' +
        format.replace(/%s/g, function() {
          return args[argIndex++];
        });
      if (typeof console !== 'undefined') {
        console.error(message);
      }
      try {
        // This error was thrown as a convenience so that you can use this stack
        // to find the callsite that caused this warning to fire.
        throw new Error(message);
      } catch(x) {}
    }
  };
}

module.exports = warning;