node_modules/is-module/index.js

// no idea what these regular expressions do,
// but i extracted it from https://github.com/yahoo/js-module-formats/blob/master/index.js#L18
var ES6ImportExportRegExp = /(?:^\s*|[}{\(\);,\n]\s*)(import\s+['"]|(import|module)\s+[^"'\(\)\n;]+\s+from\s+['"]|export\s+(\*|\{|default|function|var|const|let|[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*))/;

var ES6AliasRegExp = /(?:^\s*|[}{\(\);,\n]\s*)(export\s*\*\s*from\s*(?:'([^']+)'|"([^"]+)"))/;

module.exports = function (sauce) {
  return ES6ImportExportRegExp.test(sauce)
    || ES6AliasRegExp.test(sauce);
};