API调用返回的Contract_ABI存在JSON接口错误

Question

我正在尝试通过从BSCCAN测试网API获取合约ABI来设置智能合约。我已经成功地获得了USDT的合同ABI(https://testnet.bscscan.com/address/0x337610d27c682e347c9cd60bd4b3b107c9d34ddd)从TESTNET API然而，当我试图设置合同时，我得到了这个错误：

Error: You must provide the json interface of the contract when instantiating a contract object.
at Contract (C:UsersUserDocumentsCoding Projectstrading-bot - modifiednode_modulesweb3-eth-contractsrcindex.js:70:15)
at new Contract (C:UsersUserDocumentsCoding Projectstrading-bot - modifiednode_modulesweb3-ethsrcindex.js:149:22)

以下是我在main((函数中运行的异步函数，用于获取ABI

// Funciton to get the token ABI that uses the BSCSCAN API to get the token you want (IN THIS CASE USDT)
async function getTokenWanted(){
let tokenAddress = '0x337610d27c682e347c9cd60bd4b3b107c9d34ddd';
let tokenWantedAPI = "https://api-testnet.bscscan.com/api?module=contract&action=getabi&address="+tokenAddress+"&apikey=" +process.env.BSCSCAN_API;
try {
const res = await fetch(tokenWantedAPI);
const headerDate = res.headers && res.headers.get('date') ? res.headers.get('date') : 'no response date';
console.log('Status Code:', res.status);
console.log('Date in Response header:', headerDate);
let users = await res.json();
contractABI =users.result;
return contractABI
} catch (err) {
console.log(err.message); //can be console.error
}
}
// Function to setup the token contract 
async function setupTokenWantedContract(){
let contract_ABI = await getTokenWanted();
console.log(contract_ABI);
let token_Address ='0x337610d27c682e347c9cd60bd4b3b107c9d34ddd';
const tokenContract = new web3.eth.Contract(contract_ABI, token_Address);

return tokenContract;
}

这些功能运行在如下的主功能中：

async function main(){
let tokenWantedContract = awaitsetupTokenWantedContract()
}

当登录到控制台时，收集的ABI合同是这样的(这与您在bscscan中转到合同ABI并将其复制并粘贴到代码中时完全相同，但是我希望动态地这样做，因此我使用API(：

[{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"previousOwner","type":"address"},{"indexed":true,"internalType":"address","name":"newOwner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"constant":true,"inputs":[],"name":"_decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"_name","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"_symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"getOwner","outputs":[{"internalType":"address","name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"mint","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"renounceOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"}] 

以下是我迄今为止尝试的内容：

• 将api的结果包装成JSON.Passe((，但如果它是否包装在JSON.Parse((中，则错误是相同的

Answer 1

显然，当我使用JSON时，我以某种方式让它工作起来

// Funciton to get the token ABI that uses the BSCSCAN API to get the token you want (IN THIS CASE USDT)
async function getTokenWanted(){
let tokenAddress = '0x337610d27c682e347c9cd60bd4b3b107c9d34ddd';
let tokenWantedAPI = "https://api-testnet.bscscan.com/api?module=contract&action=getabi&address="+tokenAddress+"&apikey=" +process.env.BSCSCAN_API;
try {
const res = await fetch(tokenWantedAPI);
const headerDate = res.headers && res.headers.get('date') ? res.headers.get('date') : 'no response date';
console.log('Status Code:', res.status);
console.log('Date in Response header:', headerDate);
let users = await res.json();
contractABI =JSON.parse(users.result);
return contractABI
} catch (err) {
console.log(err.message); //can be console.error
}
}

奇怪的是，当我第一次尝试JSON.Parse((.时，一定是出了问题