Function stringify

test/angular/1.6/angular.js:2191–2210

(value)

}

function stringify(value) {
  if (value == null) { // null || undefined
    return '';
  }
  switch (typeof value) {
    case 'string':
      break;
    case 'number':
      value = '' + value;
      break;
    default:
      if (hasCustomToString(value) && !isArray(value) && !isDate(value)) {
        value = value.toString();
      } else {
        value = toJson(value);
      }
  }

  return value;
}

var NODE_TYPE_ELEMENT = 1;
var NODE_TYPE_ATTRIBUTE = 2;