Web3.js: Creating "newBlockHeaders" subscription on Parity returns error

[baxy]

Expected behavior

The params array inside the json rpc call should not contain an empty object when creating subscription to "newBlockHeaders". The call should be:
{"method":"eth_subscribe","params":["newHeads"],"id":1,"jsonrpc":"2.0"}

Actual behavior

When creating the subscription for "newBlockHeaders", the json rpc call sends in the params array an extra parameter, to be more specific an empty object:
{"method":"eth_subscribe","params":["newHeads", {}],"id":1,"jsonrpc":"2.0"}

Therefor Parity returns the following error:
{"code":-32602,"message":"Couldn't parse parameters: newHeads","data":"\"Expected no parameters.\""}

On Geth it's working and no errors are returned, but Parity seems more strict.

Steps to reproduce the behavior

const Web3 = require('web3');
const web3 = new Web3("ws://localhost:8546"); // This needs to be a Parity node

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

    return;
  }

  console.error(error);
}).on("data", (blockHeader) => {
  console.log(blockHeader);
}).on("error", (error) => {
  console.error(error)
});

Error Logs

Error: Provider error: Error: Node error: {"code":-32602,"message":"Couldn't parse parameters: newHeads","data":"\"Expected no parameters.\""}
    at /debug-app/node_modules/web3-providers/dist/web3-providers.cjs.js:334:15
    at <anonymous>
    at process._tickCallback (internal/process/next_tick.js:189:7)

Versions

Parity 2.2.8-stable and 2.2.9-stable
NPM 6.4.1
Node 8.15.0
Web3js 1.0.0-beta.46
OS Ubuntu 18.04

Using Web3js 1.0.0-beta.37, the pre-migration to ES6 version is working. I did a quick verification and the rpc call does not contain the extra empty object in the params array when creating the above mentioned subscription.

[nivida]

Thanks for submitting this issue I’ll fix it asap.

[nivida]

Tested it with a parity node and the version beta.46 and it works without a problem. Are you sure that you are using version beta.46 of the Web3.js lib?

[baxy]

Yes, I am sure it was beta.46. Retested now with a clean "npm install" and no more errors.
It is odd indeed, the issue can be closed, thank you.