records/mpp: add MPP struct to create corresponding tlv.Record

Used to encode/decode MPP tlv records

record/record_test.go

@@ -0,0 +1,73 @@
+package record_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/lightningnetwork/lnd/lnwire"
+	"github.com/lightningnetwork/lnd/record"
+	"github.com/lightningnetwork/lnd/tlv"
+)
+
+type recordEncDecTest struct {
+	name      string
+	encRecord func() tlv.RecordProducer
+	decRecord func() tlv.RecordProducer
+	assert    func(*testing.T, interface{})
+}
+
+var (
+	testTotal = lnwire.MilliSatoshi(45)
+	testAddr  = [32]byte{0x01, 0x02}
+)
+
+var recordEncDecTests = []recordEncDecTest{
+	{
+		name: "mpp",
+		encRecord: func() tlv.RecordProducer {
+			return record.NewMPP(testTotal, testAddr)
+		},
+		decRecord: func() tlv.RecordProducer {
+			return new(record.MPP)
+		},
+		assert: func(t *testing.T, r interface{}) {
+			mpp := r.(*record.MPP)
+			if mpp.TotalMsat() != testTotal {
+				t.Fatal("incorrect total msat")
+			}
+			if mpp.PaymentAddr() != testAddr {
+				t.Fatal("incorrect payment addr")
+			}
+		},
+	},
+}
+
+// TestRecordEncodeDecode is a generic test framework for custom TLV records. It
+// asserts that records can encode and decode themselves, and that the value of
+// the original record matches the decoded record.
+func TestRecordEncodeDecode(t *testing.T) {
+	for _, test := range recordEncDecTests {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			r := test.encRecord()
+			r2 := test.decRecord()
+			encStream := tlv.MustNewStream(r.Record())
+			decStream := tlv.MustNewStream(r2.Record())
+
+			test.assert(t, r)
+
+			var b bytes.Buffer
+			err := encStream.Encode(&b)
+			if err != nil {
+				t.Fatalf("unable to encode record: %v", err)
+			}
+
+			err = decStream.Decode(bytes.NewReader(b.Bytes()))
+			if err != nil {
+				t.Fatalf("unable to decode record: %v", err)
+			}
+
+			test.assert(t, r2)
+		})
+	}
+}