wip: add deserialize for Digeset

base/src/hash.rs

@@ -1,6 +1,11 @@
+use std::fmt;
+
 use crate::{addressing::Address, error::UpEndError};
 use multihash::Hasher;
-use serde::{ser, Serialize, Serializer};
+use serde::{
+    de::{self, Visitor},
+    ser, Deserialize, Deserializer, Serialize, Serializer,
+};
 
 #[derive(Debug, Clone, Eq, PartialEq, Hash)]
 #[cfg_attr(feature = "diesel", derive(diesel::FromSqlRow))]
@@ -29,6 +34,34 @@ impl Serialize for Digest {
     }
 }
 
+struct DigestVisitor;
+
+impl<'de> Visitor<'de> for DigestVisitor {
+    type Value = Digest;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("a valid UpEnd address (hash/UUID) as a multi-hashed string")
+    }
+
+    fn visit_str<E>(self, str: &str) -> Result<Self::Value, E>
+    where
+        E: de::Error,
+    {
+        b58_decode(str)
+            .map(|v| Digest(v))
+            .map_err(|e| de::Error::custom(format!("Error deserializing digest: {}", e)))
+    }
+}
+
+impl<'de> Deserialize<'de> for Digest {
+    fn deserialize<D>(deserializer: D) -> Result<Digest, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_str(DigestVisitor)
+    }
+}
+
 #[cfg(feature = "diesel")]
 impl diesel::types::FromSql<diesel::sql_types::Binary, diesel::sqlite::Sqlite> for Digest {
     fn from_sql(