Respond with latest for pending block number requests

go/enclave/components/batch_registry.go

@@ -177,10 +177,8 @@ func (br *batchRegistry) GetBatchAtHeight(height gethrpc.BlockNumber) (*core.Bat
 			return nil, fmt.Errorf("could not retrieve genesis rollup. Cause: %w", err)
 		}
 		batch = genesisBatch
-	case gethrpc.PendingBlockNumber:
-		// todo - depends on the current pending rollup; leaving it for a different iteration as it will need more thought
-		return nil, fmt.Errorf("requested balance for pending block. This is not handled currently")
-	case gethrpc.SafeBlockNumber, gethrpc.FinalizedBlockNumber, gethrpc.LatestBlockNumber:
+	// note: our API currently treats all these block statuses the same for obscuro batches
+	case gethrpc.SafeBlockNumber, gethrpc.FinalizedBlockNumber, gethrpc.LatestBlockNumber, gethrpc.PendingBlockNumber:
 		headBatch, err := br.storage.FetchBatchBySeqNo(br.headBatchSeq.Uint64())
 		if err != nil {
 			return nil, fmt.Errorf("batch with requested height %d was not found. Cause: %w", height, err)

go/host/rpc/clientapi/client_api_eth.go

@@ -9,7 +9,6 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/obscuronet/go-obscuro/go/common"
-	"github.com/obscuronet/go-obscuro/go/common/errutil"
 	"github.com/obscuronet/go-obscuro/go/common/host"
 	"github.com/obscuronet/go-obscuro/go/common/log"
 	"github.com/obscuronet/go-obscuro/go/responses"
@@ -207,7 +206,9 @@ type FeeHistoryResult struct {
 // Given a batch number, returns the hash of the batch with that number.
 func (api *EthereumAPI) batchNumberToBatchHash(batchNumber rpc.BlockNumber) (*gethcommon.Hash, error) {
 	// Handling the special cases first. No special handling is required for rpc.EarliestBlockNumber.
-	if batchNumber == rpc.LatestBlockNumber {
+	// note: our API currently treats all these block statuses the same for obscuro batches
+	if batchNumber == rpc.LatestBlockNumber || batchNumber == rpc.PendingBlockNumber ||
+		batchNumber == rpc.FinalizedBlockNumber || batchNumber == rpc.SafeBlockNumber {
 		batchHeader, err := api.host.DB().GetHeadBatchHeader()
 		if err != nil {
 			return nil, err
@@ -216,10 +217,6 @@ func (api *EthereumAPI) batchNumberToBatchHash(batchNumber rpc.BlockNumber) (*ge
 		return &batchHash, nil
 	}
 
-	if batchNumber == rpc.PendingBlockNumber {
-		return nil, errutil.ErrNoImpl
-	}
-
 	batchNumberBig := big.NewInt(batchNumber.Int64())
 	batchHash, err := api.host.DB().GetBatchHash(batchNumberBig)
 	if err != nil {