@ieigen/zkzru/src/cerc20Account.js

An implementation of [ZK-ZKRollup](https://github.com/ieigen/ZKZRU) in which the relayer **does not** publish transaction data to the main chain, but only publishes the new Merkle root at every update. This provides gas savings but not data availability g

const buildMimc7 = require("circomlibjs").buildMimc7;
const pc = require("@ieigen/anonmisc/lib/pedersen_babyJubjub.ts");

module.exports = class CERC20Account {
  constructor(
      _index = 0, _pubkeyX = 0, _pubkeyY = 0,
      _balanceCommX = 0, _balanceCommY = 0, _nonce = 0, _tokenType = 0,
      _prvkey = 0
  ) {
    this.index = _index;
    this.pubkeyX = _pubkeyX;
    this.pubkeyY = _pubkeyY;
    this.balanceCommX = _balanceCommX;
    this.balanceCommY = _balanceCommY;
    this.nonce = _nonce;
    this.tokenType = _tokenType;

    this.prvkey = _prvkey;
    this.hash = undefined
    this.mimcjs = undefined
    this.eddsa = undefined
  }

  async initialize() {
    this.mimcjs = await buildMimc7()
    this.hash = this.hashAccount()
  }

  hashAccount() {
    let input = [
      // this.index.toString(),
      this.pubkeyX,
      this.pubkeyY,
      this.balanceCommX,
      this.balanceCommY,
      this.nonce,
      this.tokenType
    ]
    return this.mimcjs.multiHash(input)
  }

  async debitAndIncreaseNonce(amountCommX, amountCommY) {
    if (!(amountCommX == 0 && amountCommY == 0)) {
      let res = await pc.sub([this.balanceCommX, this.balanceCommY], [amountCommX, amountCommY]);
      this.balanceCommX = res[0]
      this.balanceCommY = res[1]
    }
    this.nonce++;
    this.hash = this.hashAccount()
  }

  async credit(amountCommX, amountCommY) {
    if (this.index > 0) { // do not credit zero leaf
      let res = await pc.add([this.balanceCommX, this.balanceCommY], [amountCommX, amountCommY])
      this.balanceCommX = res[0]
      this.balanceCommY = res[1]
      this.hash = this.hashAccount()
    }
  }
}