Fix Leading Zero Issue for taiko

src/Nethermind/Nethermind.Serialization.Json/ValueHash256Converter.cs

@@ -32,6 +32,6 @@ public override void Write(
         ValueHash256 keccak,
         JsonSerializerOptions options)
     {
-        ByteArrayConverter.Convert(writer, keccak.Bytes, skipLeadingZeros: true);
+        ByteArrayConverter.Convert(writer, keccak.Bytes, skipLeadingZeros: false);
     }
 }

src/Nethermind/Nethermind.Taiko.Test/TaikoExtendedEthModuleTests.cs

@@ -78,4 +78,37 @@ public void TestL1OriginById_WithBuildPayloadArgsId()
 
         rpc.taiko_l1OriginByID(0).Result.Data.Should().Be(origin);
     }
+
+    [Test]
+    public void TestL1OriginById_ValueHash256_EvenLengthHex()
+    {
+        IL1OriginStore originStore = Substitute.For<IL1OriginStore>();
+        TaikoExtendedEthModule rpc = new TaikoExtendedEthModule(new SyncConfig(), originStore);
+        int expectedLengthInChars = ValueHash256.Length * 2 + 2;
+
+        // Create odd length hash values
+        var l2BlockHash = new ValueHash256("0x35a48c5b3ee5b1b2a365fcd1aa68c738d1c06474578087a78fa79dd45de6214");
+        var l1BlockHash = new Hash256("0x2daf7e4b06ca2d3a82c775d9e9ad0c973545a608684146cda0df5f7d71188a5");
+
+        L1Origin origin = new L1Origin(0, l2BlockHash, 1, l1BlockHash, null);
+        originStore.ReadL1Origin((UInt256)0).Returns(origin);
+
+        var result = rpc.taiko_l1OriginByID(0).Result.Data;
+        result.Should().Be(origin);
+
+        // Serialize the RPC result and verify hash values have even-length hex string
+        var serializer = new Serialization.Json.EthereumJsonSerializer();
+        var json = serializer.Serialize(result);
+
+        // Parse the JSON to extract the hash values
+        var jsonDoc = System.Text.Json.JsonDocument.Parse(json);
+        var l2BlockHashString = jsonDoc.RootElement.GetProperty("l2BlockHash").GetString();
+        var l1BlockHashString = jsonDoc.RootElement.GetProperty("l1BlockHash").GetString();
+
+        l2BlockHashString.Should().NotBeNull();
+        l2BlockHashString!.Length.Should().Be(expectedLengthInChars);
+
+        l1BlockHashString.Should().NotBeNull();
+        l1BlockHashString!.Length.Should().Be(expectedLengthInChars);
+    }
 }