Function format

spec/expect.js:567–741

(value, recurseTimes)

    };

    function format (value, recurseTimes) {
      // Provide a hook for user-specified inspect functions.
      // Check that value is an object with an inspect function on it
      if (value && typeof value.inspect === 'function' &&
          // Filter out the util module, it's inspect function is special
          value !== exports &&
          // Also filter out any prototype objects using the circular check.
          !(value.constructor && value.constructor.prototype === value)) {
        return value.inspect(recurseTimes);
      }

      // Primitive types cannot have properties
      switch (typeof value) {
        case 'undefined':
          return stylize('undefined', 'undefined');

        case 'string':
          var simple = '\'' + json.stringify(value).replace(/^"|"$/g, '')
                                                   .replace(/'/g, "\\'")
                                                   .replace(/\\"/g, '"') + '\'';
          return stylize(simple, 'string');

        case 'number':
          return stylize('' + value, 'number');

        case 'boolean':
          return stylize('' + value, 'boolean');
      }
      // For some reason typeof null is "object", so special case here.
      if (value === null) {
        return stylize('null', 'null');
      }

      if (isDOMElement(value)) {
        return getOuterHTML(value);
      }

      // Look up the keys of the object.
      var visible_keys = keys(value);
      var $keys = showHidden ? Object.getOwnPropertyNames(value) : visible_keys;

      // Functions without properties can be shortcutted.
      if (typeof value === 'function' && $keys.length === 0) {
        if (isRegExp(value)) {
          return stylize('' + value, 'regexp');
        } else {
          var name = value.name ? ': ' + value.name : '';
          return stylize('[Function' + name + ']', 'special');
        }
      }

      // Dates without properties can be shortcutted
      if (isDate(value) && $keys.length === 0) {
        return stylize(value.toUTCString(), 'date');
      }

      var base, type, braces;
      // Determine the object type