不能启动包含引用另一个合同函数的函数

Question

我正在尝试测试函数( test )，它包含对另一个契约函数(transferFrom)的引用。但当我测试的时候我犯了个错误。但是MyToken已经部署到了硬件网络，并且有地址。

这是一份合同

import "./MyToken.sol";

contract Staking {
    MyToken public myToken;

    function stake(uint256 _value) public {
        myToken.transferFrom(msg.sender, address(this), _value);
    }
}

这是一个测试

import { SignerWithAddress } from "@nomiclabs/hardhat-ethers/signers";
import { expect } from "chai";
import { assert } from "console";
import { ethers } from "hardhat";
import { MyToken, MyToken__factory, Staking, Staking__factory } from "../typechain";
// import { MyToken, MyToken__factory } from "../typechain";

describe("MyToken", function () {
  let staking: Staking;
  let myToken: MyToken;
  let bob: SignerWithAddress,
    alice: SignerWithAddress;

  before(async () => {
    [bob, alice] = await ethers.getSigners();
  })

  beforeEach(async () => {
    const MyToken = await ethers.getContractFactory("MyToken") as MyToken__factory;
    myToken = await MyToken.deploy() as MyToken;
    await myToken.deployed();

    const Staking = await ethers.getContractFactory("Staking") as Staking__factory;
    staking = await Staking.deploy() as Staking;
    await staking.deployed();
  })

  **it("staking", async function () {
    const value = 100;
      await staking.stake(value);
  })**

Answer 1

如果您的Staking只看上去像您在问题中共享的那样，那么您就没有设置myToken的地址。您需要在构造函数或定义中显式设置地址。

例如：

import "./MyToken.sol";

contract Staking {
    MyToken public myToken;

    constructor(address token) {
      myToken = token;
    }

    function stake(uint256 _value) public {
        myToken.transferFrom(msg.sender, address(this), _value);
    }
}

在测试中，您需要将myToken的地址传递给Staking.deploy函数：

staking = await Staking.deploy(myToken.address) as Staking;

调试的一种方法是检查您的测试是否正确初始化了myToken：

expect(await staking.myToken()).to.be.eq(myToken.address)