chore: improve error handling

crates/ffi/src/erc6492_client.rs

@@ -24,13 +24,13 @@ impl Erc6492Client {
     ) -> Result<bool, Erc6492Error> {
         let signature = signature
             .parse::<Bytes>()
-            .map_err(|e| Erc6492Error::InvalidAddress(e.to_string()))?;
+            .map_err(|e| Erc6492Error::InvalidSignature(e.to_string()))?;
         let address = address
             .parse::<Address>()
             .map_err(|e| Erc6492Error::InvalidAddress(e.to_string()))?;
         let message_hash = message_hash
             .parse::<B256>()
-            .map_err(|e| Erc6492Error::InvalidAddress(e.to_string()))?;
+            .map_err(|e| Erc6492Error::InvalidMessageHash(e.to_string()))?;
 
         let verification = erc6492::verify_signature(
             signature,

crates/ffi/src/lib.rs

@@ -145,7 +145,9 @@ mod ffi {
     }
 
     enum Erc6492Error {
+        InvalidSignature(String),
         InvalidAddress(String),
+        InvalidMessageHash(String),
         Verification(String),
     }