zpay32: test case for empty routing hints on r fields

zpay32/invoice_internal_test.go

@@ -697,18 +697,22 @@ func TestParseRouteHint(t *testing.T) {
 	testDoubleHopData, _ = bech32.ConvertBits(testDoubleHopData, 8, 5, true)
 
 	tests := []struct {
-		data   []byte
-		valid  bool
-		result []HopHint
+		data        []byte
+		valid       bool
+		result      []HopHint
+		expectedErr error
 	}{
 		{
-			data:  []byte{0x0, 0x0, 0x0, 0x0},
-			valid: false, // data too short, not multiple of 51 bytes
+			data: []byte{0x0, 0x0, 0x0, 0x0},
+			// data too short, not multiple of 51 bytes
+			valid:       false,
+			expectedErr: ErrLengthNotMultipleOfHopHint,
 		},
 		{
-			data:   []byte{},
-			valid:  true,
-			result: []HopHint{},
+			data:        []byte{},
+			valid:       false,
+			result:      []HopHint{},
+			expectedErr: ErrEmptyRouteHint,
 		},
 		{
 			data:   testSingleHopData,
@@ -716,8 +720,11 @@ func TestParseRouteHint(t *testing.T) {
 			result: testSingleHop,
 		},
 		{
-			data:  append(testSingleHopData, 0x0),
-			valid: false, // data too long, not multiple of 51 bytes
+			data: append(testSingleHopData,
+				[]byte{0x0, 0x0}...),
+			// data too long, not multiple of 51 bytes
+			valid:       false,
+			expectedErr: ErrLengthNotMultipleOfHopHint,
 		},
 		{
 			data:   testDoubleHopData,
@@ -732,6 +739,7 @@ func TestParseRouteHint(t *testing.T) {
 			t.Errorf("routing info decoding test %d failed: %v", i, err)
 			return
 		}
+		require.ErrorIs(t, err, test.expectedErr)
 		if test.valid {
 			if err := compareRouteHints(test.result, routeHint); err != nil {
 				t.Fatalf("test %d failed decoding routing info: %v", i, err)