Move ChainId to Currency conversion code to utils::caip2 module

src/identity/did_pkh.rs

@@ -28,7 +28,7 @@ impl DidPkh {
     }
 
     pub fn currency(&self) -> Option<Currency> {
-        (&self.chain_id).try_into().ok()
+        self.chain_id.currency()
     }
 }
 

src/utils/caip2.rs

@@ -11,6 +11,8 @@ use serde::{
     de::Error as DeserializerError,
 };
 
+use super::currencies::Currency;
+
 const CAIP2_RE: &str = r"(?P<namespace>[-a-z0-9]{3,8}):(?P<reference>[-a-zA-Z0-9]{1,32})";
 const CAIP2_ETHEREUM_NAMESPACE: &str = "eip155";
 const CAIP2_MONERO_NAMESPACE: &str = "monero"; // unregistered namespace
@@ -54,6 +56,15 @@ impl ChainId {
             .map_err(|_| ChainIdError("invalid EIP-155 chain ID"))?;
         Ok(chain_id)
     }
+
+    pub fn currency(&self) -> Option<Currency> {
+        let currency = match self.namespace.as_str() {
+            CAIP2_ETHEREUM_NAMESPACE => Currency::Ethereum,
+            CAIP2_MONERO_NAMESPACE => Currency::Monero,
+            _ => return None,
+        };
+        Some(currency)
+    }
 }
 
 #[derive(thiserror::Error, Debug)]
@@ -181,4 +192,18 @@ mod tests {
         let error = chain_id.ethereum_chain_id().err().unwrap();
         assert!(matches!(error, ChainIdError("namespace is not eip155")));
     }
+
+    #[test]
+    fn test_chain_id_conversion() {
+        let ethereum_chain_id = ChainId::ethereum_mainnet();
+        let currency = ethereum_chain_id.currency().unwrap();
+        assert_eq!(currency, Currency::Ethereum);
+
+        let monero_chain_id = ChainId {
+            namespace: "monero".to_string(),
+            reference: "mainnet".to_string(),
+        };
+        let currency = monero_chain_id.currency().unwrap();
+        assert_eq!(currency, Currency::Monero);
+    }
 }

src/utils/currencies.rs

@@ -1,7 +1,6 @@
 use regex::Regex;
 
-use crate::errors::{ConversionError, ValidationError};
-use super::caip2::ChainId;
+use crate::errors::ValidationError;
 
 #[derive(Debug, PartialEq)]
 pub enum Currency {
@@ -29,19 +28,6 @@ impl Currency {
     }
 }
 
-impl TryFrom<&ChainId> for Currency {
-    type Error = ConversionError;
-
-    fn try_from(value: &ChainId) -> Result<Self, Self::Error> {
-        let currency = match value.namespace.as_str() {
-            "eip155" => Self::Ethereum,
-            "monero" => Self::Monero, // not standard
-            _ => return Err(ConversionError),
-        };
-        Ok(currency)
-    }
-}
-
 pub fn validate_wallet_address(
     currency: &Currency,
     wallet_address: &str,
@@ -63,20 +49,6 @@ pub fn validate_wallet_address(
 mod tests {
     use super::*;
 
-    #[test]
-    fn test_chain_id_conversion() {
-        let ethereum_chain_id = ChainId::ethereum_mainnet();
-        let currency = Currency::try_from(&ethereum_chain_id).unwrap();
-        assert_eq!(currency, Currency::Ethereum);
-
-        let monero_chain_id = ChainId {
-            namespace: "monero".to_string(),
-            reference: "mainnet".to_string(),
-        };
-        let currency = Currency::try_from(&monero_chain_id).unwrap();
-        assert_eq!(currency, Currency::Monero);
-    }
-
     #[test]
     fn test_get_currency_field_name() {
         let ethereum = Currency::Ethereum;