Question

我创建了一个ERC20 SC，这是初始供应量100000000000。但是，当我运行单元测试（松露测试）以显示帐户的总余额[0]，而实际金额为99999998877时，预期金额应为是1000亿。有人可以向我解释，为什么会这样？谢谢。

it("should return the total supply", function() {

    return CToken.deployed().then(function(instance){

     return tokenInstance.totalSupply.call();
    }).then(function(result){
     assert.equal(result.toNumber(), 100000000000, 'total supply is wrong');
    })
  });

  it("should return the balance of token owner", function() {

    var token;
    return CToken.deployed().then(function(instance){
        token = instance
      return tokenInstance.balanceOf.call(accounts[0]);
    }).then(function(result){
      assert.equal(result.toNumber(), 99999998877, 'balance is wrong');
    })
  });


Contract code:
pragma solidity >=0.4.21 <0.6.0;

import "../node_modules/openzeppelin-solidity/contracts/token/ERC20/StandardToken.sol";
import "../node_modules/openzeppelin-solidity/contracts/ownership/Ownable.sol";

/**
* @title BearToken is a basic ERC20 Token
*/
contract CToken is StandardToken, Ownable{

    uint256 public totalSupply;
    string public name;
    string public symbol;
    uint32 public decimals;

    /**
    * @dev assign totalSupply to account creating this contract
    */
    constructor() public {
        symbol = "CT";
        name = "CToken";
        decimals = 18;
        totalSupply = 100000000000;

        owner = msg.sender;
        balances[msg.sender] = totalSupply;

        //emit Transfer(0x0, msg.sender, totalSupply);
    }

}

Answer 1

您的总供应量是10 ^ 29（10 ^ 11个令牌，每个令牌有10 ^ 18个小数点），这不是javascript数字可以安全处理的。 https://docs.ethers.io/ethers.js/html/notes.html#why-can-t-i-just-use-numbers

web3返回一个BN实例，不要将其转换为数字。

您可以这样声明：

const BN = web3.utils.BN
const ten = new BN("10")
const expected = ten.pow(new BN("27"))
assert(result.eq(expected), "Result doesn't match expected value")

代币拥有者的实际金额未按预期显示

1 个答案: