1const { ApiPromise, WsProvider } = require('@polkadot/api');23const connect = async () => {4 const wsEndpoint = 'ws://127.0.0.1:9944';5 const api = new ApiPromise({provider: new WsProvider(wsEndpoint)});6 await api.isReadyOrError;78 try {9 const head = (await api.rpc.chain.getHeader()).number.toNumber();10 if(head < 1) throw Error('No block #1');11 } finally {12 await api.disconnect();13 }14};1516const sleep = time => {17 return new Promise(resolve => {18 setTimeout(() => resolve(), time);19 });20};2122const main = async () => {23 while(true) {24 try {25 await connect();26 break;27 }28 catch(e) {29 await sleep(10000);30 }31 }32}3334main().then(() => process.exit(0)).catch(e => {35 console.error(e);36 process.exit(1);37});