Merge pull request #1037 from AArnott/fix1033

Fix formatting of default `ImmutableArray<T>` values
MessagePack-CSharp · Sep 14, 2020 · 4a93481 · 4a93481
2 parents 5920a07 + 71f78d5
commit 4a93481
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Showing 2 changed files with 42 additions and 13 deletions.
diff --git a/src/MessagePack.ImmutableCollection/Formatters.cs b/src/MessagePack.ImmutableCollection/Formatters.cs
@@ -15,16 +15,19 @@ public class ImmutableArrayFormatter<T> : IMessagePackFormatter<ImmutableArray<T
     {
         public void Serialize(ref MessagePackWriter writer, ImmutableArray<T> value, MessagePackSerializerOptions options)
         {
-            if (value == null)
+            if (value.IsDefault)
             {
                 writer.WriteNil();
             }
+            else if (value.IsEmpty)
+            {
+                writer.WriteArrayHeader(0);
+            }
             else
             {
                 IMessagePackFormatter<T> formatter = options.Resolver.GetFormatterWithVerify<T>();
 
                 writer.WriteArrayHeader(value.Length);
-
                 foreach (T item in value)
                 {
                     formatter.Serialize(ref writer, item, options);
@@ -36,14 +39,17 @@ public ImmutableArray<T> Deserialize(ref MessagePackReader reader, MessagePackSe
         {
             if (reader.TryReadNil())
             {
-                return ImmutableArray<T>.Empty;
+                return default;
             }
             else
             {
-                IMessagePackFormatter<T> formatter = options.Resolver.GetFormatterWithVerify<T>();
-
                 var len = reader.ReadArrayHeader();
+                if (len == 0)
+                {
+                    return ImmutableArray<T>.Empty;
+                }
 
+                IMessagePackFormatter<T> formatter = options.Resolver.GetFormatterWithVerify<T>();
                 ImmutableArray<T>.Builder builder = ImmutableArray.CreateBuilder<T>(len);
                 options.Security.DepthStep(ref reader);
                 try
@@ -58,7 +64,7 @@ public ImmutableArray<T> Deserialize(ref MessagePackReader reader, MessagePackSe
                     reader.Depth--;
                 }
 
-                return builder.ToImmutable();
+                return builder.MoveToImmutable();
             }
         }
     }

diff --git a/tests/MessagePack.Tests/ExtensionTests/ImmutableCollectionTest.cs b/tests/MessagePack.Tests/ExtensionTests/ImmutableCollectionTest.cs
@@ -70,15 +70,38 @@ public void InterfaceCollectionTest()
         }
 
         [Fact]
-        public void ImmutableArrayTest()
+        public void ImmutableArray_WithContent()
         {
-            var a = ImmutableArray.CreateRange(new[] { 1, 10, 100 });
-            ImmutableArray<int>? b = ImmutableArray.CreateRange(new[] { 1, 10, 100 });
-            ImmutableArray<int>? c = null;
+            ImmutableArray<int> populated = ImmutableArray.CreateRange(new[] { 1, 10, 100 });
+            this.Convert(populated).Is(1, 10, 100);
+        }
 
-            this.Convert(a).Is(1, 10, 100);
-            this.Convert(b).Is(1, 10, 100);
-            this.Convert(c).IsNull();
+        [Fact]
+        public void ImmutableArray_Nullable_WithContent()
+        {
+            ImmutableArray<int>? populatedNullable = ImmutableArray.CreateRange(new[] { 1, 10, 100 });
+            this.Convert(populatedNullable).Is(1, 10, 100);
+        }
+
+        [Fact]
+        public void ImmutableArray_Nullable_Null()
+        {
+            ImmutableArray<int>? nullNullable = null;
+            Assert.Null(this.Convert(nullNullable));
+        }
+
+        [Fact]
+        public void ImmutableArray_Empty()
+        {
+            ImmutableArray<int> defaultArray = ImmutableArray<int>.Empty;
+            Assert.True(this.Convert(defaultArray).IsEmpty);
+        }
+
+        [Fact]
+        public void ImmutableArray_Default()
+        {
+            ImmutableArray<int> defaultArray = default;
+            Assert.True(this.Convert(defaultArray).IsDefault);
         }
     }
 }