Parse chain ID into CAIP-2 ChainId type during blockchain config deserialization

src/config/blockchain.rs

@@ -4,6 +4,7 @@ use std::path::PathBuf;
 use serde::Deserialize;
 
 use crate::ethereum::utils::{parse_caip2_chain_id, ChainIdError};
+use crate::utils::caip2::ChainId;
 
 fn default_chain_sync_step() -> u64 { 1000 }
 
@@ -11,8 +12,8 @@ fn default_chain_reorg_max_depth() -> u64 { 10 }
 
 #[derive(Clone, Deserialize)]
 pub struct BlockchainConfig {
-    // CAIP-2 chain ID (https://github.com/ChainAgnostic/CAIPs/blob/master/CAIPs/caip-2.md)
-    pub chain_id: String,
+    // CAIP-2 chain ID
+    pub chain_id: ChainId,
     // Additional information for clients
     pub chain_info: Option<HashMap<String, String>>,
     pub contract_address: String,

src/ethereum/utils.rs

@@ -10,9 +10,6 @@ use crate::utils::caip2::ChainId;
 
 #[derive(thiserror::Error, Debug)]
 pub enum ChainIdError {
-    #[error("invalid chain ID")]
-    InvalidChainId,
-
     #[error("unsupported chain")]
     UnsupportedChain,
 
@@ -21,9 +18,7 @@ pub enum ChainIdError {
 }
 
 /// Parses CAIP-2 chain ID
-pub fn parse_caip2_chain_id(chain_id: &str) -> Result<u32, ChainIdError> {
-    let chain_id = chain_id.parse::<ChainId>()
-        .map_err(|_| ChainIdError::InvalidChainId)?;
+pub fn parse_caip2_chain_id(chain_id: &ChainId) -> Result<u32, ChainIdError> {
     if chain_id.namespace != "eip155" {
         return Err(ChainIdError::UnsupportedChain);
     };
@@ -54,15 +49,15 @@ mod tests {
 
     #[test]
     fn test_parse_caip2_chain_id() {
-        let chain_id = "eip155:1";
-        let result = parse_caip2_chain_id(chain_id).unwrap();
+        let chain_id: ChainId = "eip155:1".parse().unwrap();
+        let result = parse_caip2_chain_id(&chain_id).unwrap();
         assert_eq!(result, 1);
     }
 
     #[test]
     fn test_parse_caip2_chain_id_unsupported() {
-        let chain_id = "bip122:000000000019d6689c085ae165831e93";
-        let error = parse_caip2_chain_id(chain_id).err().unwrap();
+        let chain_id: ChainId = "bip122:000000000019d6689c085ae165831e93".parse().unwrap();
+        let error = parse_caip2_chain_id(&chain_id).err().unwrap();
         assert!(matches!(error, ChainIdError::UnsupportedChain));
     }
 }

src/mastodon_api/instance/types.rs

@@ -57,7 +57,7 @@ impl InstanceInfo {
             login_message: config.login_message.clone(),
             post_character_limit: config.post_character_limit,
             blockchain_id: config.blockchain.as_ref()
-                .map(|val| val.chain_id.clone()),
+                .map(|val| val.chain_id.to_string()),
             blockchain_explorer_url: config.blockchain.as_ref()
                 .and_then(|val| val.explorer_url.clone()),
             blockchain_contract_address: config.blockchain.as_ref()

src/utils/caip2.rs

@@ -2,6 +2,7 @@
 use std::str::FromStr;
 
 use regex::Regex;
+use serde::{Deserialize, Deserializer, de::Error as DeserializerError};
 
 const CAIP2_RE: &str = r"(?P<namespace>[-a-z0-9]{3,8}):(?P<reference>[-a-zA-Z0-9]{1,32})";
 
@@ -29,6 +30,21 @@ impl FromStr for ChainId {
     }
 }
 
+impl ToString for ChainId {
+    fn to_string(&self) -> String {
+        format!("{}:{}", self.namespace, self.reference)
+    }
+}
+
+impl<'de> Deserialize<'de> for ChainId {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+        where D: Deserializer<'de>
+    {
+        String::deserialize(deserializer)?
+            .parse().map_err(DeserializerError::custom)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -39,6 +55,7 @@ mod tests {
         let chain_id = value.parse::<ChainId>().unwrap();
         assert_eq!(chain_id.namespace, "bip122");
         assert_eq!(chain_id.reference, "000000000019d6689c085ae165831e93");
+        assert_eq!(chain_id.to_string(), value);
     }
 
     #[test]
@@ -47,6 +64,7 @@ mod tests {
         let chain_id = value.parse::<ChainId>().unwrap();
         assert_eq!(chain_id.namespace, "eip155");
         assert_eq!(chain_id.reference, "1");
+        assert_eq!(chain_id.to_string(), value);
     }
 
     #[test]