From 8b4bfec6d55ef1a07903227ad0105f597f257d26 Mon Sep 17 00:00:00 2001
From: Andrew Kozin <andrew.kozin@gmail.com>
Date: Tue, 18 Jul 2023 15:06:17 +0100
Subject: [PATCH] Implement Deserialize trait for ServerAddr

---
 async-nats/src/lib.rs | 48 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/async-nats/src/lib.rs b/async-nats/src/lib.rs
index 200f88f7e..2cce37c58 100644
--- a/async-nats/src/lib.rs
+++ b/async-nats/src/lib.rs
@@ -128,7 +128,7 @@ use tracing::{debug, error};
 
 use core::fmt;
 use std::collections::HashMap;
-use std::fmt::Display;
+use std::fmt::{Display, Formatter};
 use std::iter;
 use std::net::{SocketAddr, ToSocketAddrs};
 use std::option;
@@ -141,7 +141,8 @@ use tokio::time::{interval, Duration, Interval, MissedTickBehavior};
 use url::{Host, Url};
 
 use bytes::Bytes;
-use serde::{Deserialize, Serialize};
+use serde::de::{self, Visitor};
+use serde::{Deserialize, Deserializer, Serialize};
 use serde_repr::{Deserialize_repr, Serialize_repr};
 use tokio::io;
 use tokio::sync::{mpsc, oneshot};
@@ -1252,6 +1253,29 @@ pub trait ToServerAddrs {
     fn to_server_addrs(&self) -> io::Result<Self::Iter>;
 }
 
+struct ServerAddrVisitor;
+
+impl<'de> Visitor<'de> for ServerAddrVisitor {
+    type Value = ServerAddr;
+
+    fn expecting(&self, formatter: &mut Formatter) -> std::fmt::Result {
+        formatter.write_str("a valid NATS server address")
+    }
+
+    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E> where E: de::Error {
+        ServerAddr::from_str(v).map_err(|e| de::Error::custom(e.to_string()))
+    }
+}
+
+impl<'de> Deserialize<'de> for ServerAddr {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        deserializer.deserialize_str(ServerAddrVisitor)
+    }
+}
+
 impl ToServerAddrs for ServerAddr {
     type Iter = option::IntoIter<ServerAddr>;
     fn to_server_addrs(&self) -> io::Result<Self::Iter> {
@@ -1336,4 +1360,24 @@ mod tests {
         let address = ServerAddr::from_str("nats://example.com").unwrap();
         assert_eq!(address.host(), "example.com")
     }
+
+    #[test]
+    fn deserialize_valid_server_address() {
+        let serialized = "\"nats://example.com\"";
+        let address = ServerAddr::from_str("nats://example.com").unwrap();
+
+        assert_eq!(
+            serde_json::from_str::<ServerAddr>(serialized).unwrap(),
+            address
+        );
+    }
+
+    #[test]
+    fn deserialize_invalid_server_address() {
+        let serialized = "\"this is not the address\"";
+        let result = serde_json::from_str::<ServerAddr>(serialized);
+
+        assert!(result.is_err());
+        assert!(format!("{}", result.unwrap_err()).contains("NATS server URL is invalid"));
+    }
 }