松露JS测试不起作用

Question

我在Truffle框架中有一份固定合同，无法弄清楚为什么我的JS测试无法正常工作。

我正在尝试测试“ setPlayers”功能，合同有效且测试正在运行，但我不明白如何在测试中调用该功能：

pragma solidity ^0.4.23;

contract Swindle {
    string  public eventName;
    uint public entryFee;
    string[] public players;
    string public winner;
    uint public winnings;

    function comp(string _eventName, uint _entryFee) public {
        eventName = _eventName;
        entryFee = _entryFee;
    }

    function addPlayers(string _player) public {
        players.push(_player);
    }

    function winner(string _player) public returns (string, uint) {
        winner = _player;
        winnings = (players.length * entryFee);
        return (winner, winnings);
    } 
}

测试文件：

var Swindle = artifacts.require("Swindle");

contract('Swindle', function(accounts) {

    it('sets player to stuart', function(){
        return Swindle.deployed().then(function(instance) {
            swindle = instance;
            return swindle.addPlayers.call("stuart");
        }).then(function(swindle) {
            assert.equal(swindle.players[0], "stuart", "sets the total supply");
        })
    })
})

错误：

0 passing (302ms)
  1 failing

  1) Contract: Swindle
       sets player to stuart:
     TypeError: Cannot read property '0' of undefined
      at test/test-swindle.js:10:32
      at <anonymous>
      at process._tickCallback (internal/process/next_tick.js:118:7)

Answer 1

正如您在测试中提到的，合同中没有setPlayers方法。

---

您无法在JavaScript中直接访问合同数组。 首先，您需要调用players作为方法。

it('sets player to stuart', function(){
        return Swindle.deployed().then(function(instance) {
            swindle = instance;
            return swindle.addPlayers.call("stuart");
        }).then(function(swindle) {
            return swindle.players();
        }).then(function(players) {
            assert.equal(players[0], "stuart", "sets the total supply");
        })
    })

---

您可以async/await以提高测试的可读性。

it('sets player to stuart', async () => {
    let swindle = await Swindle.deployed();
    await swindle.addPlayers.call("stuart");
    let players = await swindle.players.call();
    assert.equal(players[0], "stuart", "sets the total supply");
});