Add the ability to encode nested IList (#461)

* Support nested ILIst instances

* Undo new syntax

Co-authored-by: Roel van Bakel <roel.vanbakel@cpp.canon>

src/Types/Encoder.cs

@@ -439,6 +439,10 @@ namespace Amqp.Types
                 {
                     encoder(buffer, value, smallEncoding);
                 }
+                else if (value is IList)
+                {
+                    WriteList(buffer, (IList)value, smallEncoding);
+                }
                 else if (value is Described)
                 {
                     ((Described)value).Encode(buffer);

test/Common/EncoderTests.cs

@@ -0,0 +1,78 @@
+//  ------------------------------------------------------------------------------------
+//  Copyright (c) Microsoft Corporation
+//  All rights reserved. 
+//  
+//  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  
+//  
+//  THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, 
+//  EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES OR 
+//  CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABLITY OR 
+//  NON-INFRINGEMENT. 
+// 
+//  See the Apache Version 2.0 License for specific language governing permissions and 
+//  limitations under the License.
+//  ------------------------------------------------------------------------------------
+
+namespace Test.Amqp
+{
+    using System.Collections.Generic;
+    using System.Linq;
+    using global::Amqp;
+    using global::Amqp.Types;
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+    [TestClass]
+    public class EncoderTests
+    {
+        [TestMethod]
+        public void EncoderNestedListTest()
+        {
+            var nested = new List<List<int>>
+            {
+                new List<int> { 0, 1 },
+                new List<int> { 2, 3 },
+                new List<int> { 4 },
+            };
+
+            ByteBuffer b = new ByteBuffer(512, true);
+            Encoder.WriteList(b, nested, true);
+
+            var formatCode = Encoder.ReadFormatCode(b);
+            var list = Encoder.ReadList(b, formatCode);
+            Assert.IsTrue(list != null);
+            Assert.AreEqual(3, list.Count);
+            Assert.AreEqual(2, (list[0] as List).Count);
+            Assert.AreEqual(2, (list[1] as List).Count);
+            Assert.AreEqual(1, (list[2] as List).Count);
+        }
+
+        [TestMethod]
+        public void EncoderNestedNestedListTest()
+        {
+            var nested = new List<object>
+            {
+                new List<object> { 0, 1, new List<string> { "test" } },
+                new List<int> { 2, 3 },
+                new List<int> { 4 },
+            };
+
+            ByteBuffer b = new ByteBuffer(512, true);
+            Encoder.WriteList(b, nested, true);
+
+            var formatCode = Encoder.ReadFormatCode(b);
+            var list = Encoder.ReadList(b, formatCode);
+            Assert.IsTrue(list != null);
+            Assert.AreEqual(3, list.Count);
+            Assert.AreEqual(3, (list[0] as List).Count);
+            Assert.AreEqual(2, (list[1] as List).Count);
+            Assert.AreEqual(1, (list[2] as List).Count);
+
+            var list0 = list[0] as List;
+            var subList = (list0[2] as List).Cast<string>().ToList();
+            Assert.AreEqual(1, subList.Count);
+            Assert.AreEqual("test", subList[0]);
+        }
+    }
+}