Add connection hints to HELLO response (#239)

* Add connection hints to HELLO response

* Make field optional

Author: madchicken

lib/src/bolt/mod.rs

@@ -14,7 +14,8 @@ mod structs;
 mod summary;
 
 pub use request::{
-    Begin, Commit, Discard, Goodbye, Hello, HelloBuilder, Pull, Reset, Rollback, WrapExtra,
+    Begin, Commit, ConnectionsHints, Discard, Goodbye, Hello, HelloBuilder, Pull, Reset, Rollback,
+    WrapExtra,
 };
 pub use structs::{
     Bolt, BoltRef, Date, DateDuration, DateTime, DateTimeZoneId, DateTimeZoneIdRef, Duration,
@@ -24,7 +25,7 @@ pub use structs::{
 };
 pub use summary::{Failure, Success, Summary};
 
-use crate::packstream::{self, de, from_bytes, from_bytes_ref, ser, to_bytes, Data};
+use crate::packstream::{de, from_bytes, from_bytes_ref, ser, to_bytes, Data};
 
 pub(crate) trait Message: Serialize {
     /// Serialize this type into a packstream encoded byte slice.

lib/src/bolt/request/hello.rs

@@ -1,10 +1,10 @@
-use std::{borrow::Borrow, collections::HashMap};
+use std::borrow::Borrow;
 
 use crate::{
     bolt::{ExpectedResponse, Summary},
     Version,
 };
-use serde::{ser::SerializeMap, Deserialize, Serialize};
+use serde::{ser::SerializeMap, Deserialize, Deserializer, Serialize};
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Hello<'a> {
@@ -119,6 +119,13 @@ impl Serialize for ServerRouting<'_> {
 pub struct Response {
     pub(crate) server: String,
     pub(crate) connection_id: String,
+    pub(crate) hints: Option<ConnectionsHints>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
+pub struct ConnectionsHints {
+    #[serde(rename = "connection.recv_timeout_seconds")]
+    connection_recv_timeout_seconds: Option<u32>,
 }
 
 impl ExpectedResponse for Hello<'_> {
@@ -255,4 +262,33 @@ mod tests {
         assert_eq!(response.server, "Neo4j/4.1.4");
         assert_eq!(response.connection_id, "bolt-31");
     }
+
+    #[test]
+    fn parse_with_hints() {
+        let data = bolt()
+            .tiny_map(3)
+            .tiny_string("server")
+            .tiny_string("Neo4j/4.1.4")
+            .tiny_string("connection_id")
+            .tiny_string("bolt-31")
+            .tiny_string("hints")
+            .tiny_map(1)
+            .string8("connection.recv_timeout_seconds")
+            .tiny_int(120)
+            .build();
+
+        let response = Response::parse(data).unwrap();
+
+        assert_eq!(response.server, "Neo4j/4.1.4");
+        assert_eq!(response.connection_id, "bolt-31");
+        assert!(response.hints.is_some());
+        assert_eq!(
+            response
+                .hints
+                .unwrap()
+                .connection_recv_timeout_seconds
+                .unwrap(),
+            120
+        );
+    }
 }

lib/src/bolt/request/mod.rs

@@ -14,7 +14,7 @@ pub use commit::Commit;
 pub use discard::Discard;
 pub use extra::WrapExtra;
 pub use goodbye::Goodbye;
-pub use hello::{Hello, HelloBuilder};
+pub use hello::{ConnectionsHints, Hello, HelloBuilder};
 pub use pull::Pull;
 pub use reset::Reset;
 pub use rollback::Rollback;

lib/src/connection.rs

@@ -4,7 +4,8 @@ use crate::messages::HelloBuilder;
 #[cfg(feature = "unstable-bolt-protocol-impl-v2")]
 use {
     crate::bolt::{
-        ExpectedResponse, Hello, HelloBuilder, Message, MessageResponse, Reset, Summary,
+        ConnectionsHints, ExpectedResponse, Hello, HelloBuilder, Message, MessageResponse, Reset,
+        Summary,
     },
     log::debug,
 };
@@ -45,6 +46,9 @@ const MAX_CHUNK_SIZE: usize = 65_535 - mem::size_of::<u16>();
 pub struct Connection {
     version: Version,
     stream: BufStream<ConnectionStream>,
+    #[allow(unused)]
+    #[cfg(feature = "unstable-bolt-protocol-impl-v2")]
+    hints: Option<ConnectionsHints>,
 }
 
 impl Connection {
@@ -94,6 +98,8 @@ impl Connection {
         Connection {
             version,
             stream: BufStream::new(stream.into()),
+            #[cfg(feature = "unstable-bolt-protocol-impl-v2")]
+            hints: None,
         }
     }
 
@@ -120,7 +126,10 @@ impl Connection {
         let hello = self.send_recv_as(hello).await?;
 
         match hello {
-            Summary::Success(_msg) => Ok(()),
+            Summary::Success(msg) => {
+                self.hints = msg.metadata.hints;
+                Ok(())
+            }
             Summary::Ignored => Err(Error::RequestIgnoredError),
             Summary::Failure(msg) => Err(Error::AuthenticationError(msg.message)),
         }