TypeError: Web3.providers.WebsocketProvider is not a constructor?

Question

Trying to connect to a geth machine over websocket? JS code.

var Web3=require('web3');
var web3 = new Web3(new 
Web3.providers.WebsocketProvider('ws://10.244.5.43:8546'));
console.log(web3.isConnected());

Not sure how to connect using WebSocket?

Answer 1

I had the same issue with web3 v1.0.0 beta 30. Never got to the bottom of it but skipping the provider construction appeared to fix it:

var Web3=require('web3');
var web3 = new Web3('ws://10.244.5.43:8546');

Answer 2

I assume that you're using a version of Web3.js older than 1.0. I believe that the WebsocketProvider was added in 1.0.

Answer 3

So in my particular case, I'm using TypeScript and it appears the typings were misleading. The package web3-providers-ws says that the following import should be valid:

import { WebsocketProvider } from "web3-providers-ws"

const provider = new WebsocketProvider("<host>", { ... })

It seems the typings lies a bit (or at least, there is something else that prevent it to work as expected).

I had to do the following to overcome the problem:

import WebsocketProvider from "web3-providers-ws"

// @ts-ignore It appears default export is required otherwise it throws 'WebsocketProvider is not a constructor error', the typings says otherwise but well ...
const provider = new WebsocketProvider("<host>", { ... })

I tried to play with various tsconfig.json options around module and default imports, but did not succeed. Not sure what is not working yet, but at least I have a workaround.

Hopefully it helps someone else.