@nexusapp/extract-files/public/isExtractableFile.js

Clones a value, recursively extracting File, Blob and ReactNativeFile instances with their object paths, replacing them with null. FileList instances are treated as File instance arrays.

'use strict';

var ReactNativeFile = require('./ReactNativeFile.js');

module.exports = function isExtractableFile(value) {
  return (
    (typeof File !== 'undefined' && value instanceof File) ||
    (typeof Blob !== 'undefined' && value instanceof Blob) ||
    value instanceof ReactNativeFile
  );
};