access-client Agent.url defaults to HOST even when custom connection is used

[natevw]

I am having trouble connecting to a locally-hosted API from the web3ui KeyringProvider. I have been able to switch the URL so that the email validation HTTP POST / goes to my configured http://localhost:8787 URL. But the /validate-ws WebSocket connection continues connecting to the default https://access.web3.storage where it doesn't receive the (local) successful delegation message.

I believe the code at https://github.com/web3-storage/w3protocol/blob/27f2f60dac7c95cb9efd42a28f5abfef8bdeb197/packages/access-client/src/agent.js#L82 might be incorrect?

Based on its usage in…

• https://github.com/web3-storage/w3ui/blob/c802e9909289a113bf646f22d25e5c6fbd1c1d3e/packages/react-keyring/src/providers/Keyring.tsx#L50 (react-keyring)
• https://github.com/web3-storage/w3ui/blob/c802e9909289a113bf646f22d25e5c6fbd1c1d3e/packages/solid-keyring/src/providers/Keyring.ts#L55 (solid-keyring)
• https://github.com/web3-storage/w3ui/blob/c802e9909289a113bf646f22d25e5c6fbd1c1d3e/packages/vue-keyring/src/providers/Keyring.ts#L62 (vue-keyring)
• (^^^ which all funnel through https://github.com/web3-storage/w3ui/blob/c802e9909289a113bf646f22d25e5c6fbd1c1d3e/packages/keyring-core/src/index.ts#L135)

…it seems that the assignment should probably fallback first to the connection's URL before jumping straight to using the default. I.e. something like:

this.url = options.connection?.url ?? options.url ?? new URL(HOST) 

so that if a connection is provided its URL is used, otherwise falling back to an auto-created connection. Does that match the intent of the connection vs. url options, or would there ever be a use case to have an Agent.url mismatched versus the Agent.connection.url?

---

Background to reproduce:

Using the tips from https://filecoinproject.slack.com/archives/C02BZPRS9HP/p1669658502951759?thread_ts=1669658366.189139&cid=C02BZPRS9HP, I have added a file retaining the "staging-service.js" name for simplicity, although this is pointing at a local service instead:

import { connect } from '@ucanto/client'
import { CAR, CBOR, HTTP } from '@ucanto/transport'
import * as DID from '@ipld/dag-ucan/did'

DID.parse('did:key:z6MkwTYX2JHHd8bmaEuDdS1LJjrpFspirjDcQ4DvAiDP49Gm')
export const accessServiceURL = new URL('http://localhost:8787')
export const accessServicePrincipal = DID.parse('did:web:local.web3.storage')

export const accessServiceConnection = connect({
  id: accessServicePrincipal,
  encoder: CAR,
  decoder: CBOR,
  channel: HTTP.open({
    url: accessServiceURL,
    method: 'POST'
  })
})

Which I put as a sibling and use from "w3ui/examples/react/sign-up-in/src/App.jsx" by adding/changing the lines:

import { accessServicePrincipal, accessServiceConnection } from './staging-service.js'

//…

<KeyringProvider servicePrincipal={accessServicePrincipal} connection={accessServiceConnection}>