amulet verification code

amulet.ts

import { utils } from 'ethers'

export interface Amulet {
  value: string;
  hash: string;
  count: number;
}

const getAmuletCount = (hash: string): number => {
  const matches = hash.match(/(8)\1*/g);
  if (!matches) return 0;
  return Math.max(...matches.map(match => match.length));
}
const isValidAmuletCount = (count: number) => count >= 4;

export const toValidAmulet = (value: string): Amulet | undefined => {
  const bytes = utils.toUtf8Bytes(value);
  if (bytes.length > 64) return;

  const hash = utils.sha256(bytes);
  const count = getAmuletCount(hash);
  if (!isValidAmuletCount(count)) return;

  return {value, hash, count}
}

// The following adds the option to upload a .txt and scan it for amulets using the classic @shrugs code
// Any amulets found will be saved in a csv. 
// You can change the "64" in the code "data.match(/.{1,64}/g)" to find shorter amulets

const fs = require('fs')
function writeCsv(data){
  fs.writeFile("amulets.csv",data, function(err){
    if (err) return console.error(err)
    console.log ("amulets saved")
  })
}

fs.readFile("yourfilehere.txt","utf8", function(err,data){
  if (err) throw err
  const strings = data.match(/.{1,64}/g)
  // const strings = data.split (".")
  const amulets = strings.filter(result => toValidAmulet(result)).reduce((acc, result) => acc + `${result}\n`,"")
  writeCsv(amulets)
})