o1js/src/examples/zkapps/voting/member.ts

TypeScript framework for zk-SNARKs and zkApps

import { Field, PublicKey, UInt64, Poseidon, MerkleWitness, Struct } from 'o1js';

export class MyMerkleWitness extends MerkleWitness(3) {}
let w = {
  isLeft: false,
  sibling: Field(0),
};
let dummyWitness = Array.from(Array(MyMerkleWitness.height - 1).keys()).map(() => w);

export class Member extends Struct({
  publicKey: PublicKey,
  balance: UInt64,

  // need this to keep track of votes for candidates
  votes: Field,

  witness: MyMerkleWitness,
  votesWitness: MyMerkleWitness,
}) {
  constructor(publicKey: PublicKey, balance: UInt64) {
    super({
      publicKey,
      balance,
      votes: Field(0),
      witness: new MyMerkleWitness(dummyWitness),
      votesWitness: new MyMerkleWitness(dummyWitness),
    });
  }

  getHash(): Field {
    return Poseidon.hash(
      this.publicKey.toFields().concat(this.balance.toFields()).concat(this.votes.toFields())
    );
  }

  addVote(): Member {
    this.votes = this.votes.add(1);
    return this;
  }

  static empty<T extends new (...args: any) => any>(): InstanceType<T> {
    return new Member(PublicKey.empty(), UInt64.zero) as any;
  }

  static from(publicKey: PublicKey, balance: UInt64) {
    return new Member(publicKey, balance);
  }
}