feat: add lib serializer for 0x-prefixed string

Author: hstove

stacks-common/src/util/serde_serializers.rs

@@ -131,3 +131,23 @@ pub mod prefix_opt_hex_codec {
         Ok(Some(val))
     }
 }
+
+/// Serialize strings as 0x-prefixed strings.
+pub mod prefix_string_0x {
+    use serde::{Deserialize, Deserializer, Serializer};
+
+    pub fn serialize<S: Serializer>(val: &str, s: S) -> Result<S::Ok, S::Error> {
+        s.serialize_str(&format!("0x{}", val))
+    }
+
+    pub fn deserialize<'de, D: Deserializer<'de>>(d: D) -> Result<String, D::Error> {
+        let s: String = Deserialize::deserialize(d)?;
+        let Some(hex_str) = s.get(2..) else {
+            return Err(serde::de::Error::invalid_length(
+                s.len(),
+                &"at least length 2 string",
+            ));
+        };
+        Ok(hex_str.to_string())
+    }
+}

testnet/stacks-node/src/event_dispatcher.rs

@@ -78,7 +78,9 @@ use stacks_common::types::chainstate::{BlockHeaderHash, BurnchainHeaderHash, Sta
 use stacks_common::types::net::PeerHost;
 use stacks_common::util::hash::{bytes_to_hex, Sha512Trunc256Sum};
 use stacks_common::util::secp256k1::MessageSignature;
-use stacks_common::util::serde_serializers::{prefix_hex, prefix_hex_codec, prefix_opt_hex};
+use stacks_common::util::serde_serializers::{
+    prefix_hex, prefix_hex_codec, prefix_opt_hex, prefix_string_0x,
+};
 use url::Url;
 
 #[cfg(any(test, feature = "testing"))]
@@ -331,14 +333,6 @@ impl RewardSetEventPayload {
     }
 }
 
-pub fn hex_prefix_string<S: serde::Serializer>(
-    hex_string: &String,
-    s: S,
-) -> Result<S::Ok, S::Error> {
-    let prefixed = format!("0x{hex_string}");
-    s.serialize_str(&prefixed)
-}
-
 #[derive(Debug, PartialEq, Clone, Serialize, Deserialize)]
 pub struct TransactionEventPayload<'a> {
     #[serde(with = "prefix_hex")]
@@ -352,7 +346,7 @@ pub struct TransactionEventPayload<'a> {
     /// The raw transaction result
     pub raw_result: Value,
     /// The hex encoded raw transaction
-    #[serde(serialize_with = "hex_prefix_string")]
+    #[serde(with = "prefix_string_0x")]
     pub raw_tx: String,
     /// The contract interface
     pub contract_interface: Option<ContractInterface>,