Make casting to string non nullable, make casting null byte[] throw, make (string null) constructor throw, fix add methods to not store raw nulls

Author: xPaw

ValveKeyValue/ValveKeyValue.Test/ConversionCoverageTestCase.cs

@@ -213,10 +213,9 @@ public void ImplicitByteArrayToKVObject()
         }
 
         [Test]
-        public void NullByteArrayToKVObjectIsNull()
+        public void NullByteArrayToKVObjectThrows()
         {
-            KVObject v = (byte[])null;
-            Assert.That(v.IsNull, Is.True);
+            Assert.That(() => { KVObject v = (byte[])null!; }, Throws.ArgumentNullException);
         }
 
         #endregion

ValveKeyValue/ValveKeyValue.Test/EdgeCaseTestCase.cs

@@ -336,6 +336,16 @@ public void EmptyArrayIteratesEmpty()
             Assert.That(items, Is.Empty);
         }
 
+        [Test]
+        public void AddNullElementToArrayStoresNullType()
+        {
+            var obj = KVObject.Array();
+            obj.Add((KVObject)null!);
+
+            Assert.That(obj.Count, Is.EqualTo(1));
+            Assert.That(obj[0].IsNull, Is.True);
+        }
+
         #endregion
 
         #region KVObject flag mutation
@@ -501,6 +511,26 @@ public void TryAddAlwaysReturnsTrueForListCollection()
             Assert.That(obj.Count, Is.EqualTo(2));
         }
 
+        [Test]
+        public void AddNullValueStoresNullType()
+        {
+            var obj = KVObject.ListCollection();
+            obj.Add("key", null!);
+
+            Assert.That(obj.Count, Is.EqualTo(1));
+            Assert.That(obj["key"].IsNull, Is.True);
+        }
+
+        [Test]
+        public void TryAddNullValueStoresNullType()
+        {
+            var obj = KVObject.Collection();
+            obj.TryAdd("key", null!);
+
+            Assert.That(obj.Count, Is.EqualTo(1));
+            Assert.That(obj["key"].IsNull, Is.True);
+        }
+
         #endregion
 
         #region CreateArray from KVObject enumerable

ValveKeyValue/ValveKeyValue.Test/KVObjectApiTestCase.cs

@@ -130,11 +130,9 @@ public void ConstructorWithIntPtr()
         }
 
         [Test]
-        public void ConstructorWithNullString()
+        public void ConstructorWithNullStringThrows()
         {
-            var obj = new KVObject((string)null);
-            Assert.That(obj.ValueType, Is.EqualTo(KVValueType.Null));
-            Assert.That(obj.IsNull, Is.True);
+            Assert.That(() => new KVObject((string)null!), Throws.ArgumentNullException);
         }
 
         #endregion
@@ -580,12 +578,9 @@ public void KV3DeserializationChildrenIterable()
         #region Null string handling
 
         [Test]
-        public void NullStringProducesNullTypedKVObject()
+        public void NullStringImplicitOperatorThrows()
         {
-            KVObject value = (string)null;
-
-            Assert.That(value.ValueType, Is.EqualTo(KVValueType.Null));
-            Assert.That(value.IsNull, Is.True);
+            Assert.That(() => { KVObject value = (string)null!; }, Throws.ArgumentNullException);
         }
 
         #endregion

ValveKeyValue/ValveKeyValue.Test/KVObjectCastTestCase.cs

@@ -264,6 +264,18 @@ static IEnumerable CommonFailures
             }
         }
 
+        [Test]
+        public void CastingNullKVObjectToStringThrows()
+        {
+            Assert.That(() => (string)(KVObject)null!, Throws.InstanceOf<NullReferenceException>());
+        }
+
+        [Test]
+        public void CastingNullKVObjectToInt32Throws()
+        {
+            Assert.That(() => (int)(KVObject)null!, Throws.InstanceOf<NullReferenceException>());
+        }
+
         [TestCase(typeof(bool))]
         [TestCase(typeof(byte))]
         [TestCase(typeof(char))]

ValveKeyValue/ValveKeyValue/KVObject.cs

@@ -69,16 +69,10 @@ public KVObject()
 
         /// <summary>
         /// Initializes a new instance of the <see cref="KVObject"/> class with a string value.
-        /// If <paramref name="value"/> is <c>null</c>, creates a null-valued instance.
         /// </summary>
         public KVObject(string value)
         {
-            if (value is null)
-            {
-                ValueType = KVValueType.Null;
-                return;
-            }
-
+            ArgumentNullException.ThrowIfNull(value);
             ValueType = KVValueType.String;
             _ref = value;
         }
@@ -322,7 +316,7 @@ public bool ContainsKey(string name)
         public void Add(string key, KVObject value)
         {
             ArgumentNullException.ThrowIfNull(key);
-            TryInsert(key, value, InsertionBehavior.ThrowOnExisting);
+            TryInsert(key, value ?? Null(), InsertionBehavior.ThrowOnExisting);
         }
 
         /// <summary>
@@ -333,7 +327,7 @@ public void Add(string key, KVObject value)
         public bool TryAdd(string key, KVObject value)
         {
             ArgumentNullException.ThrowIfNull(key);
-            return TryInsert(key, value, InsertionBehavior.None);
+            return TryInsert(key, value ?? Null(), InsertionBehavior.None);
         }
 
         /// <summary>
@@ -346,7 +340,7 @@ public void Add(KVObject value)
                 throw new InvalidOperationException($"Cannot add an array element to a {ValueType} value.");
             }
 
-            GetArrayList().Add(value);
+            GetArrayList().Add(value ?? Null());
         }
 
         /// <summary>

ValveKeyValue/ValveKeyValue/KVObject_operators.cs

@@ -44,15 +44,14 @@ public partial class KVObject
         public static implicit operator KVObject(IntPtr value) => new(value);
 
         /// <summary>Implicit cast from <see langword="byte[]"/> to <see cref="KVObject"/>.</summary>
-        public static implicit operator KVObject(byte[] value)
-            => value is null ? Null() : Blob(value);
+        public static implicit operator KVObject(byte[] value) => Blob(value);
 
         #endregion
 
         #region Explicit operators (TO primitives)
 
         /// <summary>Explicit cast from <see cref="KVObject"/> to <see cref="string"/>.</summary>
-        public static explicit operator string?(KVObject obj) => obj?.ToString(null); // TODO: Perhaps this should throw like the rest of the operators
+        public static explicit operator string(KVObject obj) => obj.ToString(null);
 
         /// <summary>Explicit cast from <see cref="KVObject"/> to <see cref="int"/>.</summary>
         public static explicit operator int(KVObject obj) => obj.ToInt32(null);