channeldb: modify SettleInvoice to also return the invoice being settled

channeldb/invoice_test.go

@@ -99,7 +99,7 @@ func TestInvoiceWorkflow(t *testing.T) {
 	// now have the settled bit toggle to true and a non-default
 	// SettledDate
 	payAmt := fakeInvoice.Terms.Value * 2
-	if err := db.SettleInvoice(paymentHash, payAmt); err != nil {
+	if _, err := db.SettleInvoice(paymentHash, payAmt); err != nil {
 		t.Fatalf("unable to settle invoice: %v", err)
 	}
 	dbInvoice2, err := db.LookupInvoice(paymentHash)
@@ -260,7 +260,7 @@ func TestInvoiceAddTimeSeries(t *testing.T) {
 			invoice.Terms.PaymentPreimage[:],
 		)
 
-		err := db.SettleInvoice(paymentHash, 0)
+		_, err := db.SettleInvoice(paymentHash, 0)
 		if err != nil {
 			t.Fatalf("unable to settle invoice: %v", err)
 		}

channeldb/invoices.go

@@ -393,9 +393,11 @@ func (d *DB) FetchAllInvoices(pendingOnly bool) ([]Invoice, error) {
 // payment hash as fully settled. If an invoice matching the passed payment
 // hash doesn't existing within the database, then the action will fail with a
 // "not found" error.
-func (d *DB) SettleInvoice(paymentHash [32]byte, amtPaid lnwire.MilliSatoshi) error {
+func (d *DB) SettleInvoice(paymentHash [32]byte,
+	amtPaid lnwire.MilliSatoshi) (*Invoice, error) {
 
-	return d.Update(func(tx *bolt.Tx) error {
+	var settledInvoice *Invoice
+	err := d.Update(func(tx *bolt.Tx) error {
 		invoices, err := tx.CreateBucketIfNotExists(invoiceBucket)
 		if err != nil {
 			return err
@@ -420,10 +422,21 @@ func (d *DB) SettleInvoice(paymentHash [32]byte, amtPaid lnwire.MilliSatoshi) er
 			return ErrInvoiceNotFound
 		}
 
-		return settleInvoice(
+		invoice, err := settleInvoice(
 			invoices, settleIndex, invoiceNum, amtPaid,
 		)
+		if err != nil {
+			return err
+		}
+
+		settledInvoice = invoice
+		return nil
 	})
+	if err != nil {
+		return nil, err
+	}
+
+	return settledInvoice, nil
 }
 
 // InvoicesSettledSince can be used by callers to catch up any settled invoices
@@ -670,17 +683,17 @@ func deserializeInvoice(r io.Reader) (Invoice, error) {
 }
 
 func settleInvoice(invoices, settleIndex *bolt.Bucket, invoiceNum []byte,
-	amtPaid lnwire.MilliSatoshi) error {
+	amtPaid lnwire.MilliSatoshi) (*Invoice, error) {
 
 	invoice, err := fetchInvoice(invoiceNum, invoices)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	// Add idempotency to duplicate settles, return here to avoid
 	// overwriting the previous info.
 	if invoice.Terms.Settled {
-		return nil
+		return nil, nil
 	}
 
 	// Now that we know the invoice hasn't already been settled, we'll
@@ -688,13 +701,13 @@ func settleInvoice(invoices, settleIndex *bolt.Bucket, invoiceNum []byte,
 	// proper location within our time series.
 	nextSettleSeqNo, err := settleIndex.NextSequence()
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	var seqNoBytes [8]byte
 	byteOrder.PutUint64(seqNoBytes[:], nextSettleSeqNo)
 	if err := settleIndex.Put(seqNoBytes[:], invoiceNum); err != nil {
-		return err
+		return nil, err
 	}
 
 	invoice.AmtPaid = amtPaid
@@ -704,8 +717,12 @@ func settleInvoice(invoices, settleIndex *bolt.Bucket, invoiceNum []byte,
 
 	var buf bytes.Buffer
 	if err := serializeInvoice(&buf, &invoice); err != nil {
-		return nil
+		return nil, err
 	}
 
-	return invoices.Put(invoiceNum[:], buf.Bytes())
+	if err := invoices.Put(invoiceNum[:], buf.Bytes()); err != nil {
+		return nil, err
+	}
+
+	return &invoice, nil
 }