Truffle React Box - "window.ethereum" Undefined

[lloy0076]

I raised this issue:

• May Not Work Without MetaMask Extension Installed truffle-box/react-box#199

In short, I unboxed the React box, started ganache, ran the migration (and the tests succeed too).

Then when I run the client (npm run start) and visit the URL in a browser, there is an error in any browser without a MetaMask extension installed; but once I install it, the React app runs as expected.

It is possible one does need some sort of Wallet extension (which I think is what MetaMask is) for the code to work, but unfortunately it just "white screens" and there's no obvious documentation saying that such a thing is required.

There's more details in the ticket.

Is this just me?

[lloy0076]

Reading a bit further, MetaMask itself says you can detect the MetaMask by doing this:

  if (typeof window.ethereum !== 'undefined') {
    console.log('MetaMask is installed!');
  }

(see https://docs.metamask.io/wallet/get-started/detect-metamask)

And you could query window.ethereum.isMetaMask to see if it is a MetaMaskProvider.

I am not new to programming but am new to working with blockchains, solidity and so forth; so I deduce that one might be able to have any type of provider but it is an error to have no provider.

[FlaviuWeb3]

Hi @lloy0076 our engineering team will look into this. Thanks for passing the above feedback with us.