Stellar Quest 4 Check

const express = require('@runkit/tyvdh/express-endpoint/1.0.0') const sendError = require('@runkit/tyvdh/send-error/1.0.1') const { Server, Utils, Transaction, Networks } = require('stellar-sdk') const cors = require('cors') const { max, chain } = require('lodash') const app = express(exports) const server = new Server('https://horizon-testnet.stellar.org') app.use(cors()) app.get('/', check) async function check(req, res) { try { const publicKey = req.query.publicKey await server .loadAccount(publicKey) .then(async (account) => { if (account.signers.length <= 1) throw `Multisig hasn't been successfully added yet. Carefully read the instructions and try again.` const maxThreshold = max([ account.thresholds.low_threshold, account.thresholds.med_threshold, account.thresholds.high_threshold ]) const maxSigner = chain(account.signers) .filter((signer) => signer.key !== publicKey) .maxBy('weight') .value().weight if (maxSigner > maxThreshold) throw `Signer weight isn't high enough. Carefully read the instructions and try again.` const { records } = await account.transactions({order: 'desc', limit: 100}) const multisigned = chain(records) .map((record) => { if (record.source_account !== publicKey) return const transaction = new Transaction(record.envelope_xdr, Networks.TESTNET) return !Utils.verifyTxSignedBy(transaction, publicKey) }) .compact() .value() if (multisigned.length) { if (res) res.status(204).send() else console.log('OK') } else throw `Account hasn't submitted a transaction signed by a multisigner. Carefully read the instructions and try again.` }) } catch(err) { if (res) sendError(err, res) else console.error(err) } } check({query: {publicKey: 'GCHT3DCDBM3GQKN772H2JDT4EVL3SY4ZLBSAJDNO6GS4SY2V5BUXGRYN'}})