chainntfns: add new option for conf notifications to send block

In this commit, we add a new option for the existing confirmation
notification system that optionally allows the caller to specify that a
block should be included as well.

The only quirk w/ the implementation here is the neutrino backend:
usually we get filtered blocks, we so need to first fetch the block
again so we can deliver the full block to the notifier. On the notifier
end, it'll only be checking for the transactions we care about, to
sending a full block doesn't affect the correctness.

We also extend the `testBatchConfirmationNotification` test to assert
that a block is only included if the caller specifies it.

chainntnfs/btcdnotify/btcd.go

@@ -263,13 +263,14 @@ func (b *BtcdNotifier) onBlockConnected(hash *chainhash.Hash, height int32, t ti
 // chain. The slice of transactions will only be populated if the block
 // includes a transaction that confirmed one of our watched txids, or spends
 // one of the outputs currently being watched.
+//
 // TODO(halseth): this is currently used for complete blocks. Change to use
 // onFilteredBlockConnected and onFilteredBlockDisconnected, making it easier
 // to unify with the Neutrino implementation.
 type filteredBlock struct {
 	hash   chainhash.Hash
 	height uint32
-	txns   []*btcutil.Tx
+	block  *btcutil.Block
 
 	// connected is true if this update is a new block and false if it is a
 	// disconnected block.
@@ -619,6 +620,7 @@ func (b *BtcdNotifier) confDetailsManually(confRequest chainntnfs.ConfRequest,
 				BlockHash:   blockHash,
 				BlockHeight: height,
 				TxIndex:     uint32(txIndex),
+				Block:       block,
 			}, chainntnfs.TxFoundManually, nil
 		}
 	}
@@ -644,16 +646,14 @@ func (b *BtcdNotifier) handleBlockConnected(epoch chainntnfs.BlockEpoch) error {
 	newBlock := &filteredBlock{
 		hash:    *epoch.Hash,
 		height:  uint32(epoch.Height),
-		txns:    btcutil.NewBlock(rawBlock).Transactions(),
+		block:   btcutil.NewBlock(rawBlock),
 		connect: true,
 	}
 
 	// We'll then extend the txNotifier's height with the information of
 	// this new block, which will handle all of the notification logic for
 	// us.
-	err = b.txNotifier.ConnectTip(
-		&newBlock.hash, newBlock.height, newBlock.txns,
-	)
+	err = b.txNotifier.ConnectTip(newBlock.block, newBlock.height)
 	if err != nil {
 		return fmt.Errorf("unable to connect tip: %v", err)
 	}
@@ -903,15 +903,15 @@ func (b *BtcdNotifier) RegisterSpendNtfn(outpoint *wire.OutPoint,
 // channel. Once it has reached all of its confirmations, a notification will be
 // sent across the 'Confirmed' channel.
 func (b *BtcdNotifier) RegisterConfirmationsNtfn(txid *chainhash.Hash,
-	pkScript []byte,
-	numConfs, heightHint uint32) (*chainntnfs.ConfirmationEvent, error) {
+	pkScript []byte, numConfs, heightHint uint32,
+	opts ...chainntnfs.NotifierOption) (*chainntnfs.ConfirmationEvent, error) {
 
 	// Register the conf notification with the TxNotifier. A non-nil value
 	// for `dispatch` will be returned if we are required to perform a
 	// manual scan for the confirmation. Otherwise the notifier will begin
 	// watching at tip for the transaction to confirm.
 	ntfn, err := b.txNotifier.RegisterConf(
-		txid, pkScript, numConfs, heightHint,
+		txid, pkScript, numConfs, heightHint, opts...,
 	)
 	if err != nil {
 		return nil, err