Implement MySqlConnection.Clone. Fixes #720

Author: bgrainger

src/MySqlConnector/MySql.Data.MySqlClient/MySqlConnection.cs

@@ -16,6 +16,9 @@
 namespace MySql.Data.MySqlClient
 {
 	public sealed class MySqlConnection : DbConnection
+#if !NETSTANDARD1_3
+		, ICloneable
+#endif
 	{
 		public MySqlConnection()
 			: this(default)
@@ -438,6 +441,12 @@ public override async ValueTask DisposeAsync()
 			}
 		}
 
+		public MySqlConnection Clone() => new MySqlConnection(m_connectionString);
+
+#if !NETSTANDARD1_3
+		object ICloneable.Clone() => Clone();
+#endif
+
 		internal ServerSession Session
 		{
 			get

tests/SideBySide/ConnectionTests.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Data;
 using Dapper;
 using MySql.Data.MySqlClient;
 using Xunit;
@@ -141,5 +142,25 @@ public void ConnectionTimeoutExplicitValueAfterOpen()
 			connection.Open();
 			Assert.Equal(30, connection.ConnectionTimeout);
 		}
+
+		[Fact]
+		public void CloneClonesConnectionString()
+		{
+			using var connection = new MySqlConnection(AppConfig.ConnectionString);
+			using var connection2 = (MySqlConnection) connection.Clone();
+			Assert.Equal(connection.ConnectionString, connection2.ConnectionString);
+#if !BASELINE
+			Assert.Equal(AppConfig.ConnectionString, connection2.ConnectionString);
+#endif
+		}
+
+		[Fact]
+		public void CloneIsClosed()
+		{
+			using var connection = new MySqlConnection(AppConfig.ConnectionString);
+			connection.Open();
+			using var connection2 = (MySqlConnection) connection.Clone();
+			Assert.Equal(ConnectionState.Closed, connection2.State);
+		}
 	}
 }