itest: replace WaitForTxBroadcast with WaitForTxInMempool

lntest/harness.go

@@ -57,9 +57,6 @@ type NetworkHarness struct {
 	Alice *HarnessNode
 	Bob   *HarnessNode
 
-	seenTxns             chan *chainhash.Hash
-	bitcoinWatchRequests chan *txWatchRequest
-
 	// Channel for transmitting stderr output from failed lightning node
 	// to main process.
 	lndErrorChan chan error
@@ -83,19 +80,16 @@ func NewNetworkHarness(r *rpctest.Harness, b BackendConfig, lndBinary string) (
 	feeService := startFeeService()
 
 	n := NetworkHarness{
-		activeNodes:          make(map[int]*HarnessNode),
-		nodesByPub:           make(map[string]*HarnessNode),
-		seenTxns:             make(chan *chainhash.Hash),
-		bitcoinWatchRequests: make(chan *txWatchRequest),
-		lndErrorChan:         make(chan error),
-		netParams:            r.ActiveNet,
-		Miner:                r,
-		BackendCfg:           b,
-		feeService:           feeService,
-		quit:                 make(chan struct{}),
-		lndBinary:            lndBinary,
+		activeNodes:  make(map[int]*HarnessNode),
+		nodesByPub:   make(map[string]*HarnessNode),
+		lndErrorChan: make(chan error),
+		netParams:    r.ActiveNet,
+		Miner:        r,
+		BackendCfg:   b,
+		feeService:   feeService,
+		quit:         make(chan struct{}),
+		lndBinary:    lndBinary,
 	}
-	go n.networkWatcher()
 	return &n, nil
 }
 
@@ -746,81 +740,12 @@ func saveProfilesPage(node *HarnessNode) error {
 	return nil
 }
 
-// TODO(roasbeef): add a WithChannel higher-order function?
-//  * python-like context manager w.r.t using a channel within a test
-//  * possibly  adds more funds to the target wallet if the funds are not
-//    enough
-
-// txWatchRequest encapsulates a request to the harness' Bitcoin network
-// watcher to dispatch a notification once a transaction with the target txid
-// is seen within the test network.
-type txWatchRequest struct {
-	txid      chainhash.Hash
-	eventChan chan struct{}
-}
-
-// networkWatcher is a goroutine which accepts async notification
-// requests for the broadcast of a target transaction, and then dispatches the
-// transaction once its seen on the Bitcoin network.
-func (n *NetworkHarness) networkWatcher() {
-	seenTxns := make(map[chainhash.Hash]struct{})
-	clients := make(map[chainhash.Hash][]chan struct{})
-
-	for {
-
-		select {
-		case <-n.quit:
-			return
-
-		case req := <-n.bitcoinWatchRequests:
-			// If we've already seen this transaction, then
-			// immediately dispatch the request. Otherwise, append
-			// to the list of clients who are watching for the
-			// broadcast of this transaction.
-			if _, ok := seenTxns[req.txid]; ok {
-				close(req.eventChan)
-			} else {
-				clients[req.txid] = append(clients[req.txid], req.eventChan)
-			}
-		case txid := <-n.seenTxns:
-			// Add this txid to our set of "seen" transactions. So
-			// we're able to dispatch any notifications for this
-			// txid which arrive *after* it's seen within the
-			// network.
-			seenTxns[*txid] = struct{}{}
-
-			// If there isn't a registered notification for this
-			// transaction then ignore it.
-			txClients, ok := clients[*txid]
-			if !ok {
-				continue
-			}
-
-			// Otherwise, dispatch the notification to all clients,
-			// cleaning up the now un-needed state.
-			for _, client := range txClients {
-				close(client)
-			}
-			delete(clients, *txid)
-		}
-	}
-}
-
-// OnTxAccepted is a callback to be called each time a new transaction has been
-// broadcast on the network.
-func (n *NetworkHarness) OnTxAccepted(hash *chainhash.Hash) {
-	select {
-	case n.seenTxns <- hash:
-	case <-n.quit:
-		return
-	}
-}
-
-// WaitForTxBroadcast blocks until the target txid is seen on the network. If
+// WaitForTxInMempool blocks until the target txid is seen in the mempool. If
 // the transaction isn't seen within the network before the passed timeout,
 // then an error is returned.
-// TODO(roasbeef): add another method which creates queue of all seen transactions
-func (n *NetworkHarness) WaitForTxBroadcast(ctx context.Context, txid chainhash.Hash) error {
+func (n *NetworkHarness) WaitForTxInMempool(ctx context.Context,
+	txid chainhash.Hash) error {
+
 	// Return immediately if harness has been torn down.
 	select {
 	case <-n.quit:
@@ -828,20 +753,29 @@ func (n *NetworkHarness) WaitForTxBroadcast(ctx context.Context, txid chainhash.
 	default:
 	}
 
-	eventChan := make(chan struct{})
+	ticker := time.NewTicker(50 * time.Millisecond)
+	defer ticker.Stop()
 
-	n.bitcoinWatchRequests <- &txWatchRequest{
-		txid:      txid,
-		eventChan: eventChan,
-	}
+	var mempool []*chainhash.Hash
+	for {
+		select {
+		case <-ctx.Done():
+			return fmt.Errorf("wanted %v, found %v txs "+
+				"in mempool: %v", txid, len(mempool), mempool)
 
-	select {
-	case <-eventChan:
-		return nil
-	case <-n.quit:
-		return fmt.Errorf("NetworkHarness has been torn down")
-	case <-ctx.Done():
-		return fmt.Errorf("tx not seen before context timeout")
+		case <-ticker.C:
+			var err error
+			mempool, err = n.Miner.Node.GetRawMempool()
+			if err != nil {
+				return err
+			}
+
+			for _, mempoolTx := range mempool {
+				if *mempoolTx == txid {
+					return nil
+				}
+			}
+		}
 	}
 }
 
@@ -1163,7 +1097,7 @@ func (n *NetworkHarness) CloseChannel(ctx context.Context,
 				"%v", err)
 			return
 		}
-		if err := n.WaitForTxBroadcast(ctx, *closeTxid); err != nil {
+		if err := n.WaitForTxInMempool(ctx, *closeTxid); err != nil {
 			errChan <- fmt.Errorf("error while waiting for "+
 				"broadcast tx: %v", err)
 			return

lntest/itest/lnd_test.go

@@ -14079,14 +14079,9 @@ func TestLightningNetworkDaemon(t *testing.T) {
 	//
 	// We will also connect it to our chain backend.
 	minerLogDir := "./.minerlogs"
-	handlers := &rpcclient.NotificationHandlers{
-		OnTxAccepted: func(hash *chainhash.Hash, amt btcutil.Amount) {
-			lndHarness.OnTxAccepted(hash)
-		},
-	}
 	miner, minerCleanUp, err := lntest.NewMiner(
 		minerLogDir, "output_btcd_miner.log",
-		harnessNetParams, handlers,
+		harnessNetParams, &rpcclient.NotificationHandlers{},
 	)
 	require.NoError(t, err, "failed to create new miner")
 	defer func() {