routing: fix TestSendPaymentErrorRepeatedFeeInsufficient

The simulated error returned was rejected due to signature failure,
and didn't simulate correctly the insufficient fees error as
intended. Fix error by including correct signature.

routing/router_test.go

@@ -206,6 +206,30 @@ func createTestCtxFromFile(startingHeight uint32, testGraph string) (*testCtx, f
 	return createTestCtxFromGraphInstance(startingHeight, graphInstance, false)
 }
 
+// Add valid signature to channel update simulated as error received from the
+// network.
+func signErrChanUpdate(key *btcec.PrivateKey,
+	errChanUpdate *lnwire.ChannelUpdate) error {
+
+	chanUpdateMsg, err := errChanUpdate.DataToSign()
+	if err != nil {
+		return err
+	}
+
+	digest := chainhash.DoubleHashB(chanUpdateMsg)
+	sig, err := key.Sign(digest)
+	if err != nil {
+		return err
+	}
+
+	errChanUpdate.Signature, err = lnwire.NewSigFromSignature(sig)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // TestFindRoutesWithFeeLimit asserts that routes found by the FindRoutes method
 // within the channel router contain a total fee less than or equal to the fee
 // limit.
@@ -504,15 +528,22 @@ func TestChannelUpdateValidation(t *testing.T) {
 func TestSendPaymentErrorRepeatedFeeInsufficient(t *testing.T) {
 	t.Parallel()
 
+	var (
+		roasbeefSongokuChanID = uint64(12345)
+		songokuSophonChanID   = uint64(3495345)
+	)
+
 	const startingBlockHeight = 101
-	ctx, cleanUp, err := createTestCtxFromFile(startingBlockHeight, basicGraphFilePath)
+	ctx, cleanUp, err := createTestCtxFromFile(
+		startingBlockHeight, basicGraphFilePath,
+	)
 	if err != nil {
 		t.Fatalf("unable to create router: %v", err)
 	}
 	defer cleanUp()
 
 	// Craft a LightningPayment struct that'll send a payment from roasbeef
-	// to luo ji for 100 satoshis.
+	// to sophon for 1000 satoshis.
 	var payHash lntypes.Hash
 	amt := lnwire.NewMSatFromSatoshis(1000)
 	payment := LightningPayment{
@@ -525,17 +556,20 @@ func TestSendPaymentErrorRepeatedFeeInsufficient(t *testing.T) {
 	var preImage [32]byte
 	copy(preImage[:], bytes.Repeat([]byte{9}, 32))
 
-	// We'll also fetch the first outgoing channel edge from roasbeef to
+	// We'll also fetch the first outgoing channel edge from son goku
-	// son goku. We'll obtain this as we'll need to to generate the
+	// to sophon. We'll obtain this as we'll need to to generate the
 	// FeeInsufficient error that we'll send back.
-	chanID := uint64(12345)
+	_, _, edgeUpdateToFail, err := ctx.graph.FetchChannelEdgesByID(
-	_, _, edgeUpdateToFail, err := ctx.graph.FetchChannelEdgesByID(chanID)
+		songokuSophonChanID,
+	)
 	if err != nil {
 		t.Fatalf("unable to fetch chan id: %v", err)
 	}
 
 	errChanUpdate := lnwire.ChannelUpdate{
-		ShortChannelID:  lnwire.NewShortChanIDFromInt(chanID),
+		ShortChannelID: lnwire.NewShortChanIDFromInt(
+			songokuSophonChanID,
+		),
 		Timestamp:       uint32(edgeUpdateToFail.LastUpdate.Unix()),
 		MessageFlags:    edgeUpdateToFail.MessageFlags,
 		ChannelFlags:    edgeUpdateToFail.ChannelFlags,
@@ -546,13 +580,20 @@ func TestSendPaymentErrorRepeatedFeeInsufficient(t *testing.T) {
 		FeeRate:         uint32(edgeUpdateToFail.FeeProportionalMillionths),
 	}
 
+	err = signErrChanUpdate(ctx.privKeys["songoku"], &errChanUpdate)
+	if err != nil {
+		t.Fatalf("Failed to sign channel update error: %v ", err)
+	}
+
 	// We'll now modify the SendToSwitch method to return an error for the
 	// outgoing channel to Son goku. This will be a fee related error, so
 	// it should only cause the edge to be pruned after the second attempt.
 	ctx.router.cfg.Payer.(*mockPaymentAttemptDispatcher).setPaymentResult(
 		func(firstHop lnwire.ShortChannelID) ([32]byte, error) {
 
-			roasbeefSongoku := lnwire.NewShortChanIDFromInt(chanID)
+			roasbeefSongoku := lnwire.NewShortChanIDFromInt(
+				roasbeefSongokuChanID,
+			)
 			if firstHop == roasbeefSongoku {
 				return [32]byte{}, htlcswitch.NewForwardingError(
 					// Within our error, we'll add a
@@ -590,7 +631,7 @@ func TestSendPaymentErrorRepeatedFeeInsufficient(t *testing.T) {
 	// The route should have pham nuwen as the first hop.
 	if route.Hops[0].PubKeyBytes != ctx.aliases["phamnuwen"] {
 
-		t.Fatalf("route should go through satoshi as first hop, "+
+		t.Fatalf("route should go through pham nuwen as first hop, "+
 			"instead passes through: %v",
 			getAliasFromPubKey(route.Hops[0].PubKeyBytes,
 				ctx.aliases))