Web3.js websocket connection logic

Web3Connection.js

const RECONNECT_MILLIS = 2000

class Web3Connection {
    constructor() {
        this.connect()
    }

    async connect() {
        const provider = new Web3.providers.WebsocketProvider('...')
        this.web3 = new Web3(provider)

        provider.on('error', (error) => {
            console.error('WS ERROR', error)
            setTimeout(() => this.connect(), RECONNECT_MILLIS)
        })
        
        provider.on('end', (ev) => {
            console.error('WS END', ev.type, ev.code, ev.reason)
            setTimeout(() => this.connect(), RECONNECT_MILLIS)
        })

        // Handle individual subscriptions
        if (this.aSubscription) {
            await this.aSubscription.unsubscribe()
            this.aSubscription = null
        }

        this.aSubscription = this.web3.eth.subscribe('newBlockHeaders', (error) => {
            if (error) { console.error('WS BLOCKHEADER ERROR', error) }
        }).on('data', (result) => {
            console.log('BLOCK', result.number)
        })
    }
}