feat: --unlocked flag for Anvil which enables autoImpersonate on startup

[Sabnock01]

Component

Anvil

Describe the feature you would like

Currently, in order to enable auto-impersonation of accounts in Anvil, you need to call the anvil_autoImpersonate RPC method on your local Anvil instance:

This can be done through curl like so:

curl -X POST \
  http://localhost:8545 \
  -H "Content-Type: application/json" \
  -d '{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "anvil_autoImpersonateAccount",
  "params": [true]
}'

Or through cast rpc:

cast rpc anvil_autoImpersonateAccount true

It would be convenient to have an --unlocked flag when creating an Anvil instance to enable auto-impersonation on startup. Not dissimilar from the flag of the same name for cast send.

Additional context

Am happy to work on this myself if it's a feature we decide to add.

Indeed, I've already looked at the Anvil source yet have a few questions however.

[mattsse]

reasonable,
supportive

we need

1. a new config field + cli cmd field
2. if provided call the corresponding ethapi or backend function

[mattsse]

cast rpc anvil_autoImpersonateAccount true

this should work?

[Sabnock01]

cast rpc anvil_autoImpersonateAccount true

this should work?

You're correct. It does. Modified the issue. (Was sending the request incorrectly)