Fail gracefully if user hasn’t set up a wallet bridge properly.

[katelynsills]

The deployed dapp does not fail very gracefully when the user hasn’t set up a wallet bridge properly.

There’s a console error in the deployed dapp, emitted from agoric-wallet.html:

found Agoric wallet [object Object]?suggestedDappPetname=cardStore
agoric-wallet.html?suggestedDappPetname=cardStore:24 Uncaught TypeError: Failed to construct 'URL': Invalid URL
    at fromFrame (agoric-wallet.html?suggestedDappPetname=cardStore:24)

The hint appears to be an object where a string is expected. The object is the event.data in a cross-frame MessageEvent, from the local wallet, on https://local.agoric.com/?append=/wallet-bridge.html.

Originally posted by @kriskowal in #31 (comment)

[katelynsills]

Hi @michaelfig I assigned this to you because I think it will be solved by the wallet bridge component you were working on, but let me know if that's not the case.

[michaelfig]

Hi @michaelfig I assigned this to you because I think it will be solved by the wallet bridge component you were working on

It is indeed within the purview of that component. I'll take it from here.