Subscribe pending logs via SubscribeFilterLogs does not work

[sirgarfieldc]

in the original GETH for ETH L1, one could subscribe to logs emitted by pending transaction with this snippet below

localSub, err := provider.SubscribeFilterLogs(
		context.Background(),
		ethereum.FilterQuery{
			FromBlock: big.NewInt(-1),
			ToBlock:   big.NewInt(-1),
		},
		localCh,
)

I have looked through the code base of this bsc fork. It looks like this functionality should be supported

bsc/eth/filters/filter_system.go

Line 227 in 2b83693

if from == rpc.PendingBlockNumber && to == rpc.PendingBlockNumber {

Trying to do

localSub, err := provider.SubscribeFilterLogs(
		context.Background(),
		ethereum.FilterQuery{
			FromBlock: big.NewInt(-2),
			ToBlock:   big.NewInt(-2),
		},
		localCh,
)

produces this error

2023/08/11 14:25:20 failed to SubscribeFilterLogs. err=invalid argument 1: hex string without 0x prefix

Upon investigation it looks like there is a discrepancy here

bsc/ethclient/ethclient.go

Line 602 in 2b83693

pending := big.NewInt(-1)

backend used -2 to represent pendingBlock but ethclient still uses -1.

I have done this modification

pending := big.NewInt(int64(rpc.PendingBlockNumber))

After the modification, err=invalid argument 1: hex string without 0x prefix no longer shows up but there is no pending Log coming out of the channel.

Questions:
Does Subscribe pending logs via SubscribeFilterLogs work in bsc fork ? If yes, how to properly do it ? If not, why not ? (looks like backend supports it )

[0xLyon]

Hi there, unfortunately this is not currently available and you will have to use the solution suggested here for now:
#1787 (comment)

You can see more details as to why and the PR that are still required to be merged in order to allow for the mentioned subscription for pending transaction to be available:
#1783 (comment)