TypeError on window.ethereum.on('accountsChanged', ...)

[DotCoyote]

Expected behavior

The callback function from window.ethereum.on('accountsChanged', callbackFunction) is emitted without errors.

Actual behavior

The callback-function is emitted correctly, but the devTools console throws an error:

Uncaught TypeError: Cannot read property 'subscription' of undefined
    at t.exports.data (index.js?176c:105)
    at u (inpage.js:1)
    at t.exports.a.emit (inpage.js:1)
    at a.<anonymous> (inpage.js:1)
    at u (inpage.js:1)
    at a.emit (inpage.js:1)
    at inpage.js:1
    at l.write [as _write] (inpage.js:1)
    at b (inpage.js:1)
    at inpage.js:1

Going into index.js?176c:105 shows

if (result.method && _this.subscriptions.has(result.params.subscription)) {

and result only holds

{
  "method": "wallet_accountsChanged",
  "result": [
    "0x88257xxxxxxxx"
  ]
}

Steps to reproduce the behavior

1. Create an app using ethereum and web3.js
2. Add a method for window.ethereum.on('accountsChanged', handleAccountsChanged);
3. Change accounts in MetaMask with the app open
4. See the error in the console

Logs

Environment

Node: 14.4.0
npm: 6.14.5
web3.js: 1.2.11
macOS: 10.15.5
Chrome 84.0.4147.89
MetaMask 8.0.5
Chain: trufflesuite/ganache-cli:v6.9.1

[GregTheGreek]

Thank you for the report! This might be related to #3651, will investigate

[ryanio]

hey @DotCoyote thanks for reporting. i was able to recreate this with a test dapp.

it looks like now that metamask is sending this new event down the pipe (wallet_accountsChanged) the web3.js code is failing in that place since it is not expecting an event without a subscription property. We would just need to add some additional checks in that if statement, which i will open a pr for.