使用web3进行以太坊转账测试

目标：使用web3以及ethereumjs-tx实现转账功能。（本文仅作为给同事的一个demo）
章节流程：1. 实验操作。2. 结论汇总。
引用资料:https://web3js.readthedocs.io/en/v1.3.4/web3-eth.html#sendsignedtransaction

实验操作

我们在测试网ropsten进行实验，准备两个账户(作为目标账户的余额为0)。

1. 执行转账交易

执行转账（10000000）命令后，输出结果如下：

D:\exercise\nodestudy\html>node ropsten_test.js
number: 1
signedTransactionData0xf8660184646534a68252089401a54572f83124bf78ba630faef643e6812662f8839896808029a08db048a4771a817644539f78a0c94ddb1c8bbbc8fecd2b10b7b3d3d35e54dffba07528a1d2eec21ee68f7532096aaf794d02dabb97a9f9233dfd26b5d7bbcfe869
0xf8af0a766d7ec19e581551bef49d28682ff37a6821f3e50bb4c2f3ebc434bdfb
{
  blockHash: '0xf570951524f989f5aa4efd3db7df6a468419271054f3d0320584348181ecfabd',
  blockNumber: 11982020,
  contractAddress: null,
  cumulativeGasUsed: 6761800,
  effectiveGasPrice: 1684354214,
  from: '0xaa1a88aa89f50ee9b7e3f6124f18a31d5e6db1f9',
  gasUsed: 21000,
  logs: [],
  logsBloom: '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
  status: true,
  to: '0x01a54572f83124bf78ba630faef643e6812662f8',
  transactionHash: '0xf8af0a766d7ec19e581551bef49d28682ff37a6821f3e50bb4c2f3ebc434bdfb',
  transactionIndex: 6,
  type: '0x0'
}

2. 查询余额

查询目标账户的余额，结果输出如下：

D:\exercise\nodestudy\html>node ropsten_test.js
_to balance:
10000000

结论汇总

首先，转账测试成功了，整个类库的使用还是很方便的。
其次，有几个点注意下：
* 1）使用ethereumjs-tx时 'chain'默认为'mainnet'
* 2）gasPrice的值，可以去参考https://ropsten.etherscan.io/最近的交易

完整代码如下：

const Web3 = require('web3');
var _from = '0xAa1a88aa89F50ee9B7e3F6124f18a31d5E6dB1F9';
var _from_pk = '';
var _to = '0x01a54572F83124bF78BA630FAEF643e6812662f8';

const web3 = new Web3(new Web3.providers.HttpProvider('https://ropsten.infura.io/v3/9aa3d95b3bc440fa88ea12eaa4456161'))
async function transfer() {
    web3.eth.getTransactionCount(_from).then(function (number) {
        console.log(`number: ${number}`);
        var Tx = require('ethereumjs-tx').Transaction;
        var privateKey = Buffer.from(_from_pk, 'hex');
        var rawTx = {
            nonce: '0x' + number,
            gasPrice: '0x646534a6',//"1684354214",
            gasLimit: '0x5208',//"21000",
            to: _to,
            value: '0x989680',//"10000000",//'0x00',
            // data: ''
        }

        var tx = new Tx(rawTx, { 'chain': 'ropsten' });
        // var tx = new Tx(rawTx);
        tx.sign(privateKey);
        var serializedTx = tx.serialize();
        var signedTransactionData = '0x' + serializedTx.toString('hex');
        console.log("signedTransactionData" + signedTransactionData);

        web3.eth.sendSignedTransaction(signedTransactionData, function (err, hash) {
            if (!err) {
                console.log(hash);
            } else {
                console.log(err);
            }
        }).on('receipt', console.log);
    });
}

async function balance() {
    // console.log("_from balance:");
    // web3.eth.getBalance(_from).then(console.log);

    console.log("_to balance:");
    web3.eth.getBalance(_to).then(console.log);

}
async function main() {
    // transfer();
    balance();
}
if (require.main === module) {
    main();
}