Get application root in nodejs for windows and unix system

getAppRoot.ts

// Node version 12.0
// Typescript version 3.8
import fs from "fs";
import path from "path";

const getAppRoot = (curPath: string, rootIndicator = 'package.json'): string | Error=> {
  if (curPath.length === 0 || curPath === path.sep) {
    throw new Error(`Couldn't find root dir`)
  } else if (fs.existsSync(path.join(curPath, rootIndicator))) {
    return curPath
  } else {
    return getAppRoot(path.dirname(curPath))
  }
}