add some test coverage around peers map (peer_addr hashing impl) (mim…

…blewimble#3039)

p2p/tests/peer_addr.rs

@@ -0,0 +1,55 @@
+// Copyright 2019 The Grin Developers
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::collections::HashMap;
+use std::net::{IpAddr, Ipv4Addr, SocketAddr};
+
+use grin_p2p as p2p;
+
+use crate::p2p::types::PeerAddr;
+
+// Test the behavior of a hashmap of peers keyed by peer_addr.
+#[test]
+fn test_peer_addr_hashing() {
+	let mut peers: HashMap<PeerAddr, String> = HashMap::new();
+
+	let socket_addr1 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(192, 168, 0, 1)), 8080);
+	let peer_addr1 = PeerAddr(socket_addr1);
+	peers.insert(peer_addr1, "peer1".into());
+
+	assert!(peers.contains_key(&peer_addr1));
+	assert_eq!(peers.len(), 1);
+
+	let socket_addr2 = SocketAddr::new(IpAddr::V4(Ipv4Addr::new(192, 168, 0, 1)), 8081);
+	let peer_addr2 = PeerAddr(socket_addr2);
+
+	// Expected behavior here is to ignore the port when hashing peer_addr.
+	// This means the two peer_addr instances above are seen as the same addr.
+	assert!(peers.contains_key(&peer_addr1));
+	assert!(peers.contains_key(&peer_addr2));
+
+	peers.insert(peer_addr2, "peer2".into());
+
+	// Inserting the second instance is a no-op as they are treated as the same addr.
+	assert!(peers.contains_key(&peer_addr1));
+	assert!(peers.contains_key(&peer_addr2));
+	assert_eq!(peers.len(), 1);
+
+	// Check they are treated as the same even though their underlying ports are different.
+	assert_eq!(peer_addr1, peer_addr2);
+	assert_eq!(peer_addr1.0, socket_addr1);
+	assert_eq!(peer_addr2.0, socket_addr2);
+	assert_eq!(peer_addr1.0.port(), 8080);
+	assert_eq!(peer_addr2.0.port(), 8081);
+}