Function isFormData

lib/utils.js:313–326

(thing)

const FormDataCtor = typeof G.FormData !== 'undefined' ? G.FormData : undefined;

const isFormData = (thing) => {
  if (!thing) return false;
  if (FormDataCtor && thing instanceof FormDataCtor) return true;
  // Reject plain objects inheriting directly from Object.prototype so prototype-pollution gadgets can't spoof FormData.
  const proto = getPrototypeOf(thing);
  if (!proto || proto === Object.prototype) return false;
  if (!isFunction(thing.append)) return false;
  const kind = kindOf(thing);
  return (
    kind === 'formdata' ||
    // detect form-data instance
    (kind === 'object' && isFunction(thing.toString) && thing.toString() === '[object FormData]')
  );
};

/**
 * Determine if a value is a URLSearchParams object