eth/filters: send rpctransactions in pending-subscription (#26126)

This PR changes the pending tx subscription to return RPCTransaction types instead of normal Transaction objects. This will fix the inconsistencies with other tx returning API methods (i.e. getTransactionByHash), and also fill in the sender value for the tx.

co-authored by @s1na

eth/filters/api.go

@@ -29,6 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
 	"github.com/ethereum/go-ethereum/rpc"
 )
 
@@ -147,15 +148,18 @@ func (api *FilterAPI) NewPendingTransactions(ctx context.Context, fullTx *bool)
 	go func() {
 		txs := make(chan []*types.Transaction, 128)
 		pendingTxSub := api.events.SubscribePendingTxs(txs)
+		chainConfig := api.sys.backend.ChainConfig()
 
 		for {
 			select {
 			case txs := <-txs:
 				// To keep the original behaviour, send a single tx hash in one notification.
 				// TODO(rjl493456442) Send a batch of tx hashes in one notification
+				latest := api.sys.backend.CurrentHeader()
 				for _, tx := range txs {
 					if fullTx != nil && *fullTx {
-						notifier.Notify(rpcSub.ID, tx)
+						rpcTx := ethapi.NewRPCPendingTransaction(tx, latest, chainConfig)
+						notifier.Notify(rpcSub.ID, rpcTx)
 					} else {
 						notifier.Notify(rpcSub.ID, tx.Hash())
 					}

eth/filters/filter_system.go

@@ -33,6 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
 	lru "github.com/hashicorp/golang-lru"
 )
@@ -61,6 +62,8 @@ type Backend interface {
 	GetLogs(ctx context.Context, blockHash common.Hash, number uint64) ([][]*types.Log, error)
 	PendingBlockAndReceipts() (*types.Block, types.Receipts)
 
+	CurrentHeader() *types.Header
+	ChainConfig() *params.ChainConfig
 	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
 	SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription
 	SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription

eth/filters/filter_system_test.go

@@ -50,6 +50,14 @@ type testBackend struct {
 	chainFeed       event.Feed
 }
 
+func (b *testBackend) ChainConfig() *params.ChainConfig {
+	panic("implement me")
+}
+
+func (b *testBackend) CurrentHeader() *types.Header {
+	panic("implement me")
+}
+
 func (b *testBackend) ChainDb() ethdb.Database {
 	return b.db
 }