Test.js函数事件日志返回空数组-异步/等待/许诺/Tronweb问题

Question

我正在编写Tron智能合同，并在我的测试文件中提供了一个功能，它会发出一个事件。当尝试console.log日志时，我会得到一个空数组。这是因为交易延迟到shasta网络，还是还有什么东西我忽略了？我正在使用tronbox test --network shasta。

下面是我的合同的基本测试版本：

pragma solidity >=0.5.0 <0.7.0;

contract TronStack {
    
    uint public investmentCount;
    mapping (uint => Investment) public investments;

    struct Investment {
        uint id;
        uint amount;
    }

    event InvestmentCreated (
        uint id,
        uint amount
    );

    constructor() public {
    }

    function invest(uint _amount) public {
        investmentCount++;
        investments[investmentCount] = Investment(investmentCount, _amount);
        emit InvestmentCreated(investmentCount, _amount);
    }

}

这是我的js测试文件：

const TronStack = artifacts.require('./TronStack.sol')
const TronWeb = require('tronweb')

contract('TronStack', (accounts) => {
    let tronstack

    before(async () => {
        tronstack = await TronStack.deployed()
    })

    describe('deployment', async () => {
        it('deploys successfully', async () => {
            const address = await tronstack.address
            assert.notEqual(address, 0x0)
            assert.notEqual(address, '')
            assert.notEqual(address, null)
            assert.notEqual(address, undefined)

            addressTron = tronWeb.address.fromHex(address)
            console.log(addressTron) // returns contract address
        })
    })

    describe('investments', async () => {
        let result, event, investmentCount

        before(async () => {
            result = await tronstack.invest('10000000')
            event = await tronWeb.getEventByTransactionID(result)

            investmentCount = await tronstack.investmentCount()
        })

        it('adds investment', async () => {
            assert.equal(investmentCount, 1)

            console.log(result) // returns tx id
            console.log(event) // returns empty array

            // using a previous tx id prints logs as intended
            oldTX = await tronWeb.getEventByTransactionID('0c960b698ffc889c1c7df81dc2f09eace47d50c73ffc662c2e3fb1671c4515c4')
            console.log(oldTX)

        })
    })

})

测试返回如下所示：

  Contract: TronStack
    deployment
TCW4HMVoRKpQUqDhFjxXmMQkd5Hse3JXh4
      ✓ deploys successfully
    investments
047f8548dae22ea85dcd569b888e0ff2deaca1bd23b43460cb5759a736e5c6c7
[]
[
  {
    block: 7796397,
    timestamp: 1599495159000,
    contract: 'TAoE543WH1fVerZRHK5ecsKU2VPckE5mLw',
    name: 'InvestmentCreated',
    transaction: '0c960b698ffc889c1c7df81dc2f09eace47d50c73ffc662c2e3fb1671c4515c4',
    result: { '0': '1', '1': '10000000', amount: '10000000', id: '1' },
    resourceNode: 'solidityNode'
  }
]
      ✓ adds investment (133ms)


  2 passing (956ms)

Answer 1

我注意到，如果您在shasta网络上使用tronweb创建一个事务，那么在shasta tronscan上看到相同的事务需要一点时间。当您还创建一个契约时，也会发生同样的情况。

因此，为了解决这个问题，每次与智能契约交互时，我只需等待5s：

 let tx = await contract.createToken(tokenType.code, token.reference_identifier).send()
        console.log(tx)

        await setTimeout(async () => {
            await tronWeb.getEventByTransactionID(tx).then((result) => {
                console.log(result)
            })
        }, 5000)

我不喜欢在我的代码中出现这些类型的超时，但是它可以工作，我只是希望您在mainnet中没有这些问题。

编辑:我注意到有时候5秒是不够的，所以我还添加了一个do，以确保始终接收事务事件。

        // Wait 5 seconds for the transaction to propagate
        await this.sleep(5000)
        // Also do a do while, so we are sure that we get the tx event
        let result
        do {
            result = await tronWeb.getEventByTransactionID(tx).then((result) => result)
        } while (result.length === 0)
        console.log(result)