Web3.js: Subscription stopped working after 1.0.0-beta.37

[lbthomsen]

Expected behavior

Subscription event fired on each new block.

Actual behavior

Nothing.

Steps to reproduce the behavior

(async function () {

    var Web3 = require("web3");
    var web3 = new Web3("ws://localhost:8546");

    console.log("Web3 Version: ", web3.version);

    var latestBlock = await web3.eth.getBlock("latest");

    console.log("Latest Block: ", latestBlock.number);

    var subscription = web3.eth.subscribe("newBlockHeaders");

    subscription.on("data", function (blockHeader) {
        console.log("Got block: ", blockHeader.number);
    });

})();

This will work as expected up to and including 1.0.0-beta.37. In the latest version (beta-41) nothing happens - no error, no events.

Error Logs

No errors logged.

Versions

[email protected]

[nivida]

I've tested it locally and can't reproduce this behavior. Which node type are you using? (Parity, Geth, Ganache)

[lbthomsen]

Latest parity beta:

lth@ncpws04:~$ parity --version
Parity Ethereum
  version Parity-Ethereum/v2.3.2-beta-678138f-20190203/x86_64-linux-gnu/rustc1.31.1
Copyright 2015-2018 Parity Technologies (UK) Ltd.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

By Wood/Paronyan/Kotewicz/Drwięga/Volf
   Habermeier/Czaban/Greeff/Gotchac/Redmann

Private POA chain with block every 5 seconds. Subscription with beta.37 works fine.

[lbthomsen]

Actually I have a public node running. Try this - it works with beta.37 but fails with beta.43 (which by the way reports itself as 42):

/* 
 * Web3 Websocket Test
 */
(async function () {

    var Web3 = require("web3");
    var web3 = new Web3("wss://devchain.subutai.io:8546");

    console.log("Web3 Version: ", web3.version);

    var latestBlock = await web3.eth.getBlock("latest");

    console.log("Latest Block: ", latestBlock.number);

    web3.eth.subscribe("newBlockHeaders")
            .on("data", function (blockHeader) {
                console.log("Got block: ", blockHeader.number);
            });

    web3.eth.subscribe("pendingTransactions")
            .on("data", function (tx) {
                console.log("Pending tx: ", tx);
            });

})();
/*
 * vim: ts=4 et nowrap autoindent
 */

Those nodes run:

Parity Ethereum
  version Parity-Ethereum/v2.3.0-beta-10657d9-20190115/x86_64-linux-gnu/rustc1.31.1
Copyright 2015-2018 Parity Technologies (UK) Ltd.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

By Wood/Paronyan/Kotewicz/Drwięga/Volf
   Habermeier/Czaban/Greeff/Gotchac/Redmann

Notice that the wss connection works (latest block reported in both cases) only subscription fail with beta 43.

[nivida]

@lbthomsen Thanks for the detailed information I will have a look at it today!

[lbthomsen]

Just for the sake of complete info - Debian stretch with node ver. 10.15.1

[lbthomsen]

Confirmed fixed in beta.44

[wallaceturner]

There is still an issue with the callback
In 1.0.0-beta.51 if you omit the EventEmitters and just use the callback, the callback is never fired

Callback should be removed or fixed?

const subscription = web3.eth.subscribe('newBlockHeaders', function(error, result){
    if (!error) {
        console.log(result);

        return;
    }

    console.error(error);
})

Also one minor thing, the Subscription.on methods in the typings indicate it returns void however i believe this should be

on(type: 'data', handler: (data: T) => void): Subscription