Reduce = Map + Filter + ... Can you please explain why someArray.length = 0 is better than just someArray= [] - it is sort simple and more readable? About the point it gets difficult to keep track we can use Proxy We can using Map or Object console.time has some caveats that why we have Performance API https://blog.bitsrc.io/using-the-performance-web-api-with-chrome-devtools-f4c59564b3d4

You can exit and save the file with ZZ, you can learn more about it here: https://vi.stackexchange.com/questions/5723/what-are-the-differences-between-wqcr-xcr-and-zz-when-exiting-vim

why you do not use just env command?