itest: add an asset invoice with sats value reference

Author: GeorgeTsagk

itest/assets_test.go

@@ -1427,6 +1427,7 @@ func payInvoiceWithAssets(t *testing.T, payer, rfqPeer *HarnessNode,
 type invoiceConfig struct {
 	errSubStr  string
 	groupKey   []byte
+	msats      lnwire.MilliSatoshi
 	routeHints []*lnrpc.RouteHint
 }
 
@@ -1450,6 +1451,12 @@ func withInvGroupKey(groupKey []byte) invoiceOpt {
 	}
 }
 
+func withMsatAmount(amt uint64) invoiceOpt {
+	return func(c *invoiceConfig) {
+		c.msats = lnwire.MilliSatoshi(amt)
+	}
+}
+
 func createAssetInvoice(t *testing.T, dstRfqPeer, dst *HarnessNode,
 	assetAmount uint64, assetID []byte,
 	opts ...invoiceOpt) *lnrpc.AddInvoiceResponse {
@@ -1478,7 +1485,8 @@ func createAssetInvoice(t *testing.T, dstRfqPeer, dst *HarnessNode,
 		InvoiceRequest: &lnrpc.Invoice{
 			Memo: fmt.Sprintf("this is an asset invoice for "+
 				"%d units", assetAmount),
-			Expiry: timeoutSeconds,
+			Expiry:    timeoutSeconds,
+			ValueMsat: int64(cfg.msats),
 		},
 	}
 
@@ -1510,11 +1518,21 @@ func createAssetInvoice(t *testing.T, dstRfqPeer, dst *HarnessNode,
 
 	t.Logf("Got quote for %v asset units per BTC", rate)
 
-	assetUnits := rfqmath.NewBigIntFixedPoint(assetAmount, 0)
-	numMSats := rfqmath.UnitsToMilliSatoshi(assetUnits, *rate)
-	mSatPerUnit := float64(decodedInvoice.NumMsat) / float64(assetAmount)
+	var mSatPerUnit float64
+
+	if cfg.msats > 0 {
+		require.EqualValues(t, decodedInvoice.NumMsat, cfg.msats)
+		units := rfqmath.MilliSatoshiToUnits(cfg.msats, *rate)
 
-	require.EqualValues(t, numMSats, decodedInvoice.NumMsat)
+		mSatPerUnit = float64(cfg.msats) / float64(units.ToUint64())
+	} else {
+		assetUnits := rfqmath.NewBigIntFixedPoint(assetAmount, 0)
+		numMSats := rfqmath.UnitsToMilliSatoshi(assetUnits, *rate)
+		mSatPerUnit = float64(decodedInvoice.NumMsat) /
+			float64(assetAmount)
+
+		require.EqualValues(t, numMSats, decodedInvoice.NumMsat)
+	}
 
 	t.Logf("Got quote for %d mSats at %3f msat/unit from peer %x with "+
 		"SCID %d", decodedInvoice.NumMsat, mSatPerUnit,

itest/litd_custom_channels_test.go

@@ -2679,10 +2679,13 @@ func testCustomChannelsLiquidityEdgeCasesCore(ctx context.Context,
 	assertNumHtlcs(t.t, erin, 0)
 	assertNumHtlcs(t.t, fabia, 0)
 
-	// Now Fabia creates the normal invoice.
+	// Now Fabia creates another invoice. We also use a fixed msat value for
+	// the invoice. Since our itest oracle evaluates every asset to about
+	// 17.1 sats, this invoice should be a bit below 10k assets, so roughly
+	// the same volume as the previous invoice we just cancelled.
 	invoiceResp = createAssetInvoice(
-		t.t, erin, fabia, 10_000, assetID,
-		withInvGroupKey(groupID),
+		t.t, erin, fabia, 0, assetID, withInvGroupKey(groupID),
+		withMsatAmount(170_000_000),
 	)
 
 	// Now Charlie pays the invoice, again by using the manually specified