itest: test use of asset ID or group key flags

Author: guggero

itest/assets_test.go

@@ -1061,6 +1061,16 @@ func sendAssetKeySendPayment(t *testing.T, src, dst *HarnessNode, amt uint64,
 	stream, err := srcTapd.SendPayment(ctxt, request)
 	require.NoError(t, err)
 
+	// If an error is returned by the RPC method (meaning the stream itself
+	// was established, no network or auth error), we expect the error to be
+	// returned on the first read on the stream.
+	if cfg.errSubStr != "" {
+		_, err := stream.Recv()
+		require.ErrorContains(t, err, cfg.errSubStr)
+
+		return
+	}
+
 	result, err := getAssetPaymentResult(stream, false)
 	require.NoError(t, err)
 	if result.Status == lnrpc.Payment_FAILED {

itest/litd_custom_channels_test.go

@@ -1302,6 +1302,31 @@ func testCustomChannelsGroupTranchesForceClose(ctx context.Context,
 	}
 	logBalanceGroup(t.t, nodes, groupIDs, "after keysend Erin->Fabia")
 
+	// We also assert that in a grouped channel with multiple grouped asset
+	// UTXOs we get a proper error if we try to do payments or create
+	// invoices while using a single asset ID.
+	sendAssetKeySendPayment(
+		t.t, erin, fabia, keySendAmount, assetID1, fn.None[int64](),
+		withPayErrSubStr(
+			"make sure to use group key for grouped asset channels",
+		),
+	)
+	createAssetInvoice(
+		t.t, charlie, dave, 100, assetID1, withInvoiceErrSubStr(
+			"make sure to use group key for grouped asset channels",
+		),
+	)
+	invoiceResp := createAssetInvoice(
+		t.t, charlie, dave, keySendAmount, nil,
+		withInvGroupKey(groupKey),
+	)
+	payInvoiceWithAssets(
+		t.t, charlie, dave, invoiceResp.PaymentRequest, assetID1,
+		withPayErrSubStr(
+			"make sure to use group key for grouped asset channels",
+		),
+	)
+
 	// ------------
 	// Test case 3: Co-op close the channel between Charlie and Dave.
 	// ------------