lnwire: use assertEqualFunc in onion failure harness

Simplifies the code slightly and improves the error message printed if
the original and deserialized messages do not match.

lnwire/fuzz_test.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"compress/zlib"
 	"encoding/binary"
-	"reflect"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -554,16 +553,12 @@ func prefixWithFailCode(data []byte, code FailCode) []byte {
 	return data
 }
 
-// equalFunc is a function used to determine whether two deserialized messages
-// are equivalent.
-type equalFunc func(x, y any) bool
-
 // onionFailureHarnessCustom performs the actual fuzz testing of the appropriate
 // onion failure message. This function will check that the passed-in message
 // passes wire length checks, is a valid message once deserialized, and passes a
 // sequence of serialization and deserialization checks.
 func onionFailureHarnessCustom(t *testing.T, data []byte, code FailCode,
-	eq equalFunc) {
+	assertEqual assertEqualFunc) {
 
 	data = prefixWithFailCode(data, code)
 
@@ -589,12 +584,7 @@ func onionFailureHarnessCustom(t *testing.T, data []byte, code FailCode,
 	newMsg, err := DecodeFailureMessage(&b, 0)
 	require.NoError(t, err, "failed to decode serialized failure message")
 
-	require.True(
-		t, eq(msg, newMsg),
-		"original message and deserialized message are not equal: "+
-			"%v != %v",
-		msg, newMsg,
-	)
+	assertEqual(t, msg, newMsg)
 
 	// Now verify that encoding/decoding full packets works as expected.
 
@@ -628,17 +618,15 @@ func onionFailureHarnessCustom(t *testing.T, data []byte, code FailCode,
 	pktMsg, err := DecodeFailure(&pktBuf, 0)
 	require.NoError(t, err, "failed to decode failure packet")
 
-	require.True(
-		t, eq(msg, pktMsg),
-		"original message and decoded packet message are not equal: "+
-			"%v != %v",
-		msg, pktMsg,
-	)
+	assertEqual(t, msg, pktMsg)
 }
 
 func onionFailureHarness(t *testing.T, data []byte, code FailCode) {
 	t.Helper()
-	onionFailureHarnessCustom(t, data, code, reflect.DeepEqual)
+	assertEq := func(t *testing.T, x, y any) {
+		require.Equal(t, x, y)
+	}
+	onionFailureHarnessCustom(t, data, code, assertEq)
 }
 
 func FuzzFailIncorrectDetails(f *testing.F) {
@@ -646,7 +634,7 @@ func FuzzFailIncorrectDetails(f *testing.F) {
 		// Since FailIncorrectDetails.Decode can leave extraOpaqueData
 		// as nil while FailIncorrectDetails.Encode writes an empty
 		// slice, we need to use a custom equality function.
-		eq := func(x, y any) bool {
+		assertEq := func(t *testing.T, x, y any) {
 			msg1, ok := x.(*FailIncorrectDetails)
 			require.True(
 				t, ok, "msg1 was not FailIncorrectDetails",
@@ -657,16 +645,18 @@ func FuzzFailIncorrectDetails(f *testing.F) {
 				t, ok, "msg2 was not FailIncorrectDetails",
 			)
 
-			return msg1.amount == msg2.amount &&
-				msg1.height == msg2.height &&
-				bytes.Equal(
+			require.Equal(t, msg1.amount, msg2.amount)
+			require.Equal(t, msg1.height, msg2.height)
+			require.True(
+				t, bytes.Equal(
 					msg1.extraOpaqueData,
 					msg2.extraOpaqueData,
+				),
 			)
 		}
 
 		onionFailureHarnessCustom(
-			t, data, CodeIncorrectOrUnknownPaymentDetails, eq,
+			t, data, CodeIncorrectOrUnknownPaymentDetails, assertEq,
 		)
 	})
 }