Add helper functions for lnd chain notifications (#4846)

lnd-rpc-test/src/test/scala/org/bitcoins/lnd/rpc/LndRpcClientPairTest.scala

@@ -17,13 +17,13 @@ import org.bitcoins.core.psbt.PSBT
 import org.bitcoins.core.wallet.fee.{SatoshisPerKW, SatoshisPerVirtualByte}
 import org.bitcoins.crypto._
 import org.bitcoins.testkit.fixtures.DualLndFixture
-import scodec.bits.HexStringSyntax
+import scodec.bits.{ByteVector, HexStringSyntax}
 
-import scala.concurrent.Future
+import scala.concurrent.{Await, Future}
 import scala.concurrent.duration.DurationInt
 import scala.util.{Failure, Success}
 
-class LndRpcClientPairTest extends DualLndFixture {
+class LndRpcClientPairTest extends DualLndFixture with LndUtils {
 
   it must "get info from both lnds" in { param =>
     val (_, lndA, lndB) = param
@@ -196,8 +196,16 @@ class LndRpcClientPairTest extends DualLndFixture {
 
       tx <- lndA.sendOutputs(Vector(output), feeRate, spendUnconfirmed = false)
       _ <- lndA.publishTransaction(tx)
+      height <- bitcoind.getBlockCount
+      confirmedF = lndB.subscribeTxConfirmation(txId = tx.txId,
+                                                script = addr.scriptPubKey,
+                                                requiredConfs = 6,
+                                                heightHint = height)
       _ <- bitcoind.getNewAddress.flatMap(bitcoind.generateToAddress(6, _))
 
+      // await so if this fails the test doesn't hang forever
+      conf = Await.result(confirmedF, 10.seconds)
+
       detailsOpt <- lndB.getTransaction(tx.txIdBE)
       _ = assert(detailsOpt.isDefined)
       details = detailsOpt.get
@@ -213,6 +221,8 @@ class LndRpcClientPairTest extends DualLndFixture {
       assert(details.txId == tx.txIdBE)
       assert(details.outputDetails.flatMap(_.addressOpt).contains(addr))
       assert(details.amount == sendAmt)
+
+      assert(ByteVector(conf.rawTx.toByteArray) == tx.bytes)
     }
   }
 

lnd-rpc/src/main/scala/org/bitcoins/lnd/rpc/LndRpcClient.scala

@@ -950,6 +950,52 @@ class LndRpcClient(val instance: LndInstance, binaryOpt: Option[File] = None)(
       .map(_.transactions.toVector.map(LndTransactionToTxDetails))
   }
 
+  def subscribeTxConfirmation(
+      script: ScriptPubKey,
+      requiredConfs: Int,
+      heightHint: Int): Future[ConfDetails] = {
+    require(heightHint > 0,
+            s"heightHint must be greater than 0, got $heightHint")
+
+    val request =
+      ConfRequest(txid = DoubleSha256Digest.empty.bytes,
+                  script = script.asmBytes,
+                  numConfs = UInt32(requiredConfs),
+                  heightHint = UInt32(heightHint))
+
+    registerConfirmationsNotification(request)
+      .filter(_.event.isConf)
+      .runWith(Sink.head)
+      .map(_.getConf)
+  }
+
+  def subscribeTxConfirmation(
+      txId: DoubleSha256Digest,
+      script: ScriptPubKey,
+      requiredConfs: Int,
+      heightHint: Int): Future[ConfDetails] = {
+    require(heightHint > 0,
+            s"heightHint must be greater than 0, got $heightHint")
+
+    val request =
+      ConfRequest(txid = txId.bytes,
+                  script = script.asmBytes,
+                  numConfs = UInt32(requiredConfs),
+                  heightHint = UInt32(heightHint))
+
+    registerConfirmationsNotification(request)
+      .filter(_.event.isConf)
+      .runWith(Sink.head)
+      .map(_.getConf)
+  }
+
+  def registerConfirmationsNotification(
+      request: ConfRequest): Source[ConfEvent, NotUsed] = {
+    logger.trace("lnd calling RegisterConfirmationsNtfn")
+
+    chainClient.registerConfirmationsNtfn(request)
+  }
+
   def monitorInvoice(
       rHash: PaymentHashTag,
       interval: FiniteDuration = 1.second,