shineout/esm/utils/validate/isJson.js

A components library for React

function _typeof(o) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (o) { return typeof o; } : function (o) { return o && "function" == typeof Symbol && o.constructor === Symbol && o !== Symbol.prototype ? "symbol" : typeof o; }, _typeof(o); }
export default function (value) {
  if (_typeof(value) === 'object') return true;

  // In the second stage, we run the text against
  // regular expressions that look for non-JSON patterns. We are especially
  // concerned with '()' and 'new' because they can cause invocation, and '='
  // because it can cause mutation. But just to be safe, we want to reject all
  // unexpected forms.

  // We split the second stage into 4 regexp operations in order to work around
  // crippling inefficiencies in IE's and Safari's regexp engines. First we
  // replace all backslash pairs with '@' (a non-JSON character). Second, we
  // replace all simple value tokens with ']' characters. Third, we delete all
  // open brackets that follow a colon or comma or that begin the text. Finally,
  // we look to see that the remaining characters are only whitespace or ']' or
  // ',' or ':' or '{' or '}'. If that is so, then the text is safe for eval.

  // eslint-disable-next-line
  if (typeof value === 'string') {
    if (/^[\],:{}\s]*$/.test(value.replace(/\\["\\\/bfnrtu]/g, '@').replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']').replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) {
      try {
        JSON.parse(value);
        return true;
      } catch (e) {
        return false;
      }
    } else {
      return false;
    }
  } else {
    return false;
  }
}