Implement ServerRecord equality and hashing.

Fixes SteamRE#476.

SteamKit2/SteamKit2/Steam/Discovery/ServerRecord.cs

@@ -1,4 +1,4 @@
- using System;
+using System;
 using System.Net;
 
 namespace SteamKit2.Discovery
@@ -122,5 +122,55 @@ public static ServerRecord CreateWebSocketServer(string address)
 
             return new ServerRecord(endPoint, ProtocolTypes.WebSocket);
         }
+
+        #region Equality and Hashing
+
+        /// <summary>
+        /// Determines whether two objects are equal.
+        /// </summary>
+        /// <param name="left">The object on the left-hand side of the equality operator.</param>
+        /// <param name="right">The object on the right-hand side of the equality operator.</param>
+        /// <returns>true if the specified object is equal to the current object; otherwise, false.</returns>
+        public static bool operator ==(ServerRecord left, ServerRecord right)
+        {
+            if (ReferenceEquals(left, right))
+            {
+                return true;
+            }
+
+            return !ReferenceEquals(left, null) && left.Equals(right);
+        }
+
+        /// <summary>
+        /// Determines whether two objects are not equal.
+        /// </summary>
+        /// <param name="left">The object on the left-hand side of the inequality operator.</param>
+        /// <param name="right">The object on the right-hand side of the inequality operator.</param>
+        /// <returns>true if the specified object is not equal to the current object; otherwise, false.</returns>
+        public static bool operator !=(ServerRecord left, ServerRecord right)
+        {
+            return !(left == right);
+        }
+
+        /// <summary>
+        /// Determines whether the specified object is equal to the current object.
+        /// </summary>
+        /// <param name="obj"></param>
+        /// <returns>true if the specified object is equal to the current object; otherwise, false.</returns>
+        public override bool Equals(object obj)
+            => obj is ServerRecord other &&
+               EndPoint.Equals(other.EndPoint) &&
+               ProtocolTypes == other.ProtocolTypes;
+
+        /// <summary>
+        /// Hash function
+        /// </summary>
+        /// <returns>A hash code for the current object.</returns>
+        public override int GetHashCode()
+        {
+            return EndPoint.GetHashCode() ^ ProtocolTypes.GetHashCode();
+        }
+
+        #endregion
     }
 }

SteamKit2/Tests/ServerRecordFacts.cs

@@ -0,0 +1,88 @@
+using SteamKit2;
+using SteamKit2.Discovery;
+using Xunit;
+
+namespace Tests
+{
+    public class ServerRecordFacts
+    {
+        [Fact]
+        public void NullsAreEqualOperator()
+        {
+            ServerRecord l = null;
+            ServerRecord r = null;
+
+            Assert.True(l == r);
+        }
+
+        [Fact]
+        public void NullIsNotEqual()
+        {
+            var s = ServerRecord.CreateWebSocketServer("host:1");
+
+            Assert.True(s != null);
+            Assert.True(null != s);
+            Assert.False(s.Equals(null));
+            Assert.False(s == null);
+            Assert.False(null == s);
+        }
+
+        [Fact]
+        public void DifferentProtocolsAreNotEqual()
+        {
+            var l = ServerRecord.CreateServer("host", 1, ProtocolTypes.Tcp);
+            var r = ServerRecord.CreateServer("host", 1, ProtocolTypes.WebSocket);
+
+            Assert.True(l != r);
+            Assert.True(r != l);
+            Assert.False(l == r);
+            Assert.False(r == l);
+            Assert.False(l.Equals(r));
+            Assert.False(r.Equals(l));
+        }
+
+        [Fact]
+        public void DifferentEndPointsAreNotEqual()
+        {
+            var l = ServerRecord.CreateServer("host", 1, ProtocolTypes.Tcp);
+            var r = ServerRecord.CreateServer("host", 2, ProtocolTypes.Tcp);
+
+            Assert.True(l != r);
+            Assert.True(r != l);
+            Assert.False(l == r);
+            Assert.False(r == l);
+            Assert.False(l.Equals(r));
+            Assert.False(r.Equals(l));
+        }
+
+        [Fact]
+        public void DifferentEndPointsAndProtocolsAreNotEqual()
+        {
+            var l = ServerRecord.CreateServer("host", 1, ProtocolTypes.Tcp);
+            var r = ServerRecord.CreateServer("host", 2, ProtocolTypes.WebSocket);
+
+            Assert.True(l != r);
+            Assert.True(r != l);
+            Assert.False(l == r);
+            Assert.False(r == l);
+            Assert.False(l.Equals(r));
+            Assert.False(r.Equals(l));
+        }
+
+        [Fact]
+        public void SameEndPointsAndProtocolsAreEqual()
+        {
+            var l = ServerRecord.CreateServer("host", 1, ProtocolTypes.Tcp);
+            var r = ServerRecord.CreateServer("host", 1, ProtocolTypes.Tcp);
+
+            Assert.False(l != r);
+            Assert.False(r != l);
+            Assert.True(l == r);
+            Assert.True(r == l);
+            Assert.True(l.Equals(r));
+            Assert.True(r.Equals(l));
+
+            Assert.Equal(l.GetHashCode(), r.GetHashCode());
+        }
+    }
+}