eth/filters: send rpctransactions in pending-subscription

[holiman]

This PR is an alternative to #26034. This PR keeps the internal objects as *types.Transaction, and mutates it into rpc.Transaction right before it's sent on the wire.

At least I think it does, I haven't fully verified it (yet).

[s1na]

Example response:

{
  blockHash: null,
  blockNumber: null,
  from: '0x21a31ee1afc51d94c2efccaa2092ad1028285549',
  gas: '0x32918',
  gasPrice: '0x202170e400',
  maxFeePerGas: '0x202170e400',
  maxPriorityFeePerGas: '0x77359400',
  hash: '0xde8f7e26fd9dc0157c8dfb8d6742a50ee1d13077f7eb675a8b9de42374ad4e6d',
  input: '0xa9059cbb000000000000000000000000a055bdc23d5f8fa59214b18a4c892d2be87d2cc200000000000000000000000000000000000000000000000
0000000001b774000',
  nonce: '0x487572',
  to: '0xdac17f958d2ee523a2206206994597c13d831ec7',
  transactionIndex: null,
  value: '0x0',
  type: '0x2',
  accessList: [],
  chainId: '0x1',
  v: '0x1',
  r: '0x93a2c41a452a8ad03c7e31e12608650205f7b2ab8f73bef174fdb28a046ccaa8',
  s: '0x74c0b4b811807c1cb066e7082dcc9341acbeff68fcd2653c9e21e82c45e1720c'
}

Only thing is blockHash, blockNumber and transactionIndex will always be null for pending txes. But adding omitempty rules to RPCTransaction type will also change the result of getTransactionByHash for pending txes, so I guess it's best to keep as is.

[s1na]

LGTM

[s1na]

Ah gethclient's method might need to change.

Update: seems to work. I think because the JSON encoding of a rpc transaction is unmarshalable to types.Transaction.

[holiman]

Update: seems to work. I think because the JSON encoding of a rpc transaction is unmarshalable to types.Transaction.

Could you clarify this a bit? I don't understand if there's anything we need to address here

[s1na]

To clarify, IMO no change needed for gethclient. PR looks good to me!