zpay32: add payment metadata field

zpay32/invoice_test.go

@@ -27,6 +27,7 @@ var (
 	testMillisat2500uBTC = lnwire.MilliSatoshi(250000000)
 	testMillisat25mBTC   = lnwire.MilliSatoshi(2500000000)
 	testMillisat20mBTC   = lnwire.MilliSatoshi(2000000000)
+	testMillisat10mBTC   = lnwire.MilliSatoshi(1000000000)
 
 	testPaymentHash = [32]byte{
 		0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
@@ -49,11 +50,12 @@ var (
 		0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11,
 	}
 
-	testEmptyString    = ""
-	testCupOfCoffee    = "1 cup coffee"
-	testCoffeeBeans    = "coffee beans"
-	testCupOfNonsense  = "ナンセンス 1杯"
-	testPleaseConsider = "Please consider supporting this project"
+	testEmptyString     = ""
+	testCupOfCoffee     = "1 cup coffee"
+	testCoffeeBeans     = "coffee beans"
+	testCupOfNonsense   = "ナンセンス 1杯"
+	testPleaseConsider  = "Please consider supporting this project"
+	testPaymentMetadata = "payment metadata inside"
 
 	testPrivKeyBytes, _     = hex.DecodeString("e126f68f7eafcc8b74f54d269fe206be715000f94dac067d1c04a8ca3b2db734")
 	testPrivKey, testPubKey = btcec.PrivKeyFromBytes(testPrivKeyBytes)
@@ -692,6 +694,33 @@ func TestDecodeEncode(t *testing.T) {
 				}
 			},
 		},
+		{
+			// Please send 0.01 BTC with payment metadata 0x01fafaf0.
+			encodedInvoice: "lnbc10m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdp9wpshjmt9de6zqmt9w3skgct5vysxjmnnd9jx2mq8q8a04uqsp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q2gqqqqqqsgq7hf8he7ecf7n4ffphs6awl9t6676rrclv9ckg3d3ncn7fct63p6s365duk5wrk202cfy3aj5xnnp5gs3vrdvruverwwq7yzhkf5a3xqpd05wjc",
+			valid:          true,
+			decodedInvoice: func() *Invoice {
+				return &Invoice{
+					Net:         &chaincfg.MainNetParams,
+					MilliSat:    &testMillisat10mBTC,
+					Timestamp:   time.Unix(1496314658, 0),
+					PaymentHash: &testPaymentHash,
+					Description: &testPaymentMetadata,
+					Destination: testPubKey,
+					PaymentAddr: &specPaymentAddr,
+					Features: lnwire.NewFeatureVector(
+						lnwire.NewRawFeatureVector(8, 14, 48),
+						lnwire.Features,
+					),
+					Metadata: []byte{0x01, 0xfa, 0xfa, 0xf0},
+				}
+			},
+			beforeEncoding: func(i *Invoice) {
+				// Since this destination pubkey was recovered
+				// from the signature, we must set it nil before
+				// encoding to get back the same invoice string.
+				i.Destination = nil
+			},
+		},
 	}
 
 	for i, test := range tests {