source: frontend/node_modules/is-glob/index.js

/*!
 * is-glob <https://github.com/jonschlinkert/is-glob>
 *
 * Copyright (c) 2014-2017, Jon Schlinkert.
 * Released under the MIT License.
 */

var isExtglob = require('is-extglob');
var chars = { '{': '}', '(': ')', '[': ']'};
var strictCheck = function(str) {
  if (str[0] === '!') {
    return true;
  }
  var index = 0;
  var pipeIndex = -2;
  var closeSquareIndex = -2;
  var closeCurlyIndex = -2;
  var closeParenIndex = -2;
  var backSlashIndex = -2;
  while (index < str.length) {
    if (str[index] === '*') {
      return true;
    }

    if (str[index + 1] === '?' && /[\].+)]/.test(str[index])) {
      return true;
    }

    if (closeSquareIndex !== -1 && str[index] === '[' && str[index + 1] !== ']') {
      if (closeSquareIndex < index) {
        closeSquareIndex = str.indexOf(']', index);
      }
      if (closeSquareIndex > index) {
        if (backSlashIndex === -1 || backSlashIndex > closeSquareIndex) {
          return true;
        }
        backSlashIndex = str.indexOf('\\', index);
        if (backSlashIndex === -1 || backSlashIndex > closeSquareIndex) {
          return true;
        }
      }
    }

    if (closeCurlyIndex !== -1 && str[index] === '{' && str[index + 1] !== '}') {
      closeCurlyIndex = str.indexOf('}', index);
      if (closeCurlyIndex > index) {
        backSlashIndex = str.indexOf('\\', index);
        if (backSlashIndex === -1 || backSlashIndex > closeCurlyIndex) {
          return true;
        }
      }
    }

    if (closeParenIndex !== -1 && str[index] === '(' && str[index + 1] === '?' && /[:!=]/.test(str[index + 2]) && str[index + 3] !== ')') {
      closeParenIndex = str.indexOf(')', index);
      if (closeParenIndex > index) {
        backSlashIndex = str.indexOf('\\', index);
        if (backSlashIndex === -1 || backSlashIndex > closeParenIndex) {
          return true;
        }
      }
    }

    if (pipeIndex !== -1 && str[index] === '(' && str[index + 1] !== '|') {
      if (pipeIndex < index) {
        pipeIndex = str.indexOf('|', index);
      }
      if (pipeIndex !== -1 && str[pipeIndex + 1] !== ')') {
        closeParenIndex = str.indexOf(')', pipeIndex);
        if (closeParenIndex > pipeIndex) {
          backSlashIndex = str.indexOf('\\', pipeIndex);
          if (backSlashIndex === -1 || backSlashIndex > closeParenIndex) {
            return true;
          }
        }
      }
    }

    if (str[index] === '\\') {
      var open = str[index + 1];
      index += 2;
      var close = chars[open];

      if (close) {
        var n = str.indexOf(close, index);
        if (n !== -1) {
          index = n + 1;
        }
      }

      if (str[index] === '!') {
        return true;
      }
    } else {
      index++;
    }
  }
  return false;
};

var relaxedCheck = function(str) {
  if (str[0] === '!') {
    return true;
  }
  var index = 0;
  while (index < str.length) {
    if (/[*?{}()[\]]/.test(str[index])) {
      return true;
    }

    if (str[index] === '\\') {
      var open = str[index + 1];
      index += 2;
      var close = chars[open];

      if (close) {
        var n = str.indexOf(close, index);
        if (n !== -1) {
          index = n + 1;
        }
      }

      if (str[index] === '!') {
        return true;
      }
    } else {
      index++;
    }
  }
  return false;
};

module.exports = function isGlob(str, options) {
  if (typeof str !== 'string' || str === '') {
    return false;
  }

  if (isExtglob(str)) {
    return true;
  }

  var check = strictCheck;

  // optionally relax check
  if (options && options.strict === false) {
    check = relaxedCheck;
  }

  return check(str);
};