more tests for improved coverage

Capnp.Net.Runtime.Tests/DeserializationTests.cs

@@ -1,4 +1,7 @@
-using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Capnproto_test.Capnp.Test;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Linq;
 
 namespace Capnp.Net.Runtime.Tests
 {
@@ -354,5 +357,40 @@ namespace Capnp.Net.Runtime.Tests
             Assert.AreEqual(double.NegativeInfinity, asListOfDoubles[0]);
             Assert.AreEqual(double.MaxValue, asListOfDoubles[1]);
         }
+
+        [TestMethod]
+        public void NestedLists()
+        {
+            var expected = new int[][] {
+                new int[] { 1, 2, 3 },
+                new int[] { 4, 5 },
+                new int[] { 6 } };
+
+            var b = MessageBuilder.Create();
+            var dss = b.CreateObject<DynamicSerializerState>();
+            dss.SetObject(expected);
+            DeserializerState d = dss;
+            var ld = d.RequireList();
+            var result = ld.Cast2D<int>();
+            Assert.AreEqual(3, result.Count);
+            for (int i = 0; i < result.Count; i++)
+            {
+                CollectionAssert.AreEqual(expected[i], result[i].ToArray());
+            }
+
+            Assert.ThrowsException<NotSupportedException>(() => ld.Cast2D<decimal>());
+        }
+
+        [TestMethod]
+        public void LinearListWrongUse()
+        {
+            var b = MessageBuilder.Create();
+            var dss = b.CreateObject<DynamicSerializerState>();
+            dss.SetObject(new int[] { 1, 2, 3 });
+            DeserializerState d = dss;
+            var ld = d.RequireList();
+            Assert.ThrowsException<NotSupportedException>(() => ld.CastList());
+            Assert.ThrowsException<NotSupportedException>(() => ld.CastCapList<ITestInterface>());
+        }
     }
 }

Capnp.Net.Runtime.Tests/SerializationTests.cs

@@ -79,6 +79,8 @@ namespace Capnp.Net.Runtime.Tests
             Assert.ThrowsException<InvalidOperationException>(() => { list[0] = null; });
             list.Init(5);
             Assert.ThrowsException<InvalidOperationException>(() => list.Init(1));
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { var _ = list[5]; });
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { list[-1] = null; });
             var c1 = new Counters();
             var cap1 = new TestInterfaceImpl(c1);
             var c2 = new Counters();
@@ -152,6 +154,8 @@ namespace Capnp.Net.Runtime.Tests
             list.Init(7);
             Assert.ThrowsException<InvalidOperationException>(() => list.Init(1));
             Assert.AreEqual(7, list.Count);
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { var _ = list[-1]; });
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { list[7] = null; });
             var c1 = new Counters();
             var cap1 = new TestInterfaceImpl(c1);
             var obj1 = b.CreateObject<DynamicSerializerState>();
@@ -234,6 +238,7 @@ namespace Capnp.Net.Runtime.Tests
             list.Init(4);
             Assert.ThrowsException<InvalidOperationException>(() => list.Init(1));
             Assert.AreEqual(4, list.Count);
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { var _ = list[5]; });
             list[0].SomeText = "0";
             list[1].SomeText = "1";
             list[2].SomeText = "2";
@@ -265,6 +270,8 @@ namespace Capnp.Net.Runtime.Tests
             list.Init(4);
             Assert.ThrowsException<InvalidOperationException>(() => list.Init(1));
             Assert.AreEqual(4, list.Count);
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { var _ = list[5]; });
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { list[-1] = null; });
             list[0] = "0";
             list[2] = null;
             list[3] = "3";
@@ -724,5 +731,15 @@ namespace Capnp.Net.Runtime.Tests
             DeserializerState d2 = dss;
             CollectionAssert.AreEqual(expected, d2.RequireList().CastText2().ToArray());
         }
+
+        [TestMethod]
+        public void EmptyListContract()
+        {
+            var list = new EmptyList<string>();
+            Assert.AreEqual(0, list.Count);
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { var _ = list[-1]; });
+            Assert.ThrowsException<IndexOutOfRangeException>(() => { var _ = list[0]; });
+            Assert.AreEqual(0, list.ToArray().Length);
+        }
     }
 }

Capnp.Net.Runtime/EmptyList.cs

@@ -8,14 +8,14 @@ namespace Capnp
     /// <summary>
     /// Implements an empty <see cref="IReadOnlyList{T}"/>.
     /// </summary>
-    /// <typeparam name="T"></typeparam>
+    /// <typeparam name="T">list element type</typeparam>
     public class EmptyList<T> : IReadOnlyList<T>
     {
         /// <summary>
-        /// Always throws an <see cref="ArgumentOutOfRangeException"/>.
+        /// Always throws an <see cref="IndexOutOfRangeException"/>.
         /// </summary>
         /// <param name="index">Ignored</param>
-        public T this[int index] => throw new ArgumentOutOfRangeException(nameof(index));
+        public T this[int index] => throw new IndexOutOfRangeException(nameof(index));
 
         /// <summary>
         /// Always 0.

Capnp.Net.Runtime/ListDeserializer.cs

@@ -11,6 +11,9 @@ namespace Capnp
         static class GenericCasts<T>
         {
             public static Func<ListDeserializer, T>? CastFunc;
+
+            public static Func<ListDeserializer, T> GetCastFunc() => CastFunc ??
+                throw new NotSupportedException("Requested cast is not supported");
         }
 
         static ListDeserializer()
@@ -45,12 +48,7 @@ namespace Capnp
 
         T Cast<T>()
         {
-            var func = GenericCasts<T>.CastFunc;
+            return GenericCasts<T>.GetCastFunc()(this);
-
-            if (func == null)
-                throw new NotSupportedException("Requested cast is not supported");
-
-            return func(this);
         }
 
         /// <summary>
@@ -91,7 +89,7 @@ namespace Capnp
         /// <exception cref="Rpc.InvalidCapabilityInterfaceException">If <typeparamref name="T"/> does not qualify as capability interface.</exception>
         public virtual IReadOnlyList<T> CastCapList<T>() where T: class
         {
-            throw new NotSupportedException("This kind of list does not contain nested lists");
+            throw new NotSupportedException("This kind of list cannot be represented as list of capabilities");
         }
 
         object CastND(int n, Func<ListDeserializer, object> func)
@@ -158,6 +156,7 @@ namespace Capnp
         /// <exception cref="NotSupportedException">If this list cannot be represented in the desired manner.</exception>
         public IReadOnlyList<IReadOnlyList<T>> Cast2D<T>()
         {
+            GenericCasts<IReadOnlyList<T>>.GetCastFunc(); // Probe to avoid lazy NotSupportedException
             return CastList().LazyListSelect(ld => ld.Cast<IReadOnlyList<T>>());
         }
 

Capnp.Net.Runtime/ListOfBitsSerializer.cs

@@ -11,35 +11,6 @@ namespace Capnp
     /// </summary>
     public class ListOfBitsSerializer: SerializerState, IReadOnlyList<bool>
     {
-        class Enumerator : IEnumerator<bool>
-        {
-            readonly ListOfBitsSerializer _self;
-            int _pos = -1;
-
-            public Enumerator(ListOfBitsSerializer self)
-            {
-                _self = self;
-            }
-
-            public bool Current => _pos >= 0 && _pos < _self.Count ? _self[_pos] : false;
-
-            object IEnumerator.Current => Current;
-
-            public void Dispose()
-            {
-            }
-
-            public bool MoveNext()
-            {
-                return ++_pos < _self.Count;
-            }
-
-            public void Reset()
-            {
-                _pos = -1;
-            }
-        }
-
         /// <summary>
         /// Gets or sets the element at given index.
         /// </summary>
@@ -121,10 +92,16 @@ namespace Capnp
             }
         }
 
+        IEnumerable<bool> Enumerate()
+        {
+            for (int i = 0; i < Count; i++)
+                yield return this[i];
+        }
+
         /// <summary>
         /// Implements <see cref="IEnumerable{Boolean}"/>
         /// </summary>
-        public IEnumerator<bool> GetEnumerator() => new Enumerator(this);
+        public IEnumerator<bool> GetEnumerator() => Enumerate().GetEnumerator();
 
         IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
     }