Make JSON support required properties

src/libraries/System.Text.Json/src/Resources/Strings.resx

@@ -665,10 +665,10 @@
  <data name="JsonPropertyRequiredAndExtensionData" xml:space="preserve">
  <value>JsonPropertyInfo with name '{0}' for type '{1}' cannot be required and be an extension data property.</value>
  </data>
- <data name="JsonRequiredPropertiesMissingHeader" xml:space="preserve">
- <value>Type '{0}' contains required properties which were not set during deserialization:</value>
+ <data name="JsonRequiredPropertiesMissing" xml:space="preserve">
+ <value>Type '{0}' contains required properties which were not set during deserialization: {1}</value>
  </data>
- <data name="JsonRequiredPropertiesMissingItem" xml:space="preserve">
- <value>- {0}</value>
+ <data name="JsonPropertyRequiredAndIgnoreNullValues" xml:space="preserve">
+ <value>Required JSON properties cannot be used in conjunction with JsonSerializerOptions.IgnoreNullValues.</value>
  </data>
-</root>
+</root>

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Object/ObjectDefaultConverter.cs

@@ -39,7 +39,7 @@ internal override bool OnTryRead(ref Utf8JsonReader reader, Type typeToConvert,
  obj = jsonTypeInfo.CreateObject()!;
 
  jsonTypeInfo.OnDeserializing?.Invoke(obj);
- jsonTypeInfo.InitializeRequiredProperties(ref state);
+ state.Current.InitializeRequiredProperties(jsonTypeInfo);
 
  // Process all properties.
  while (true)
@@ -144,8 +144,7 @@ internal override bool OnTryRead(ref Utf8JsonReader reader, Type typeToConvert,
 
  state.Current.ReturnValue = obj;
  state.Current.ObjectState = StackFrameObjectState.CreatedObject;
-
- jsonTypeInfo.InitializeRequiredProperties(ref state);
+ state.Current.InitializeRequiredProperties(jsonTypeInfo);
  }
  else
  {
@@ -253,7 +252,7 @@ internal override bool OnTryRead(ref Utf8JsonReader reader, Type typeToConvert,
  }
 
  jsonTypeInfo.OnDeserialized?.Invoke(obj);
- jsonTypeInfo.CheckRequiredProperties(ref state);
+ state.Current.ValidateAllRequiredPropertiesAreRead(jsonTypeInfo);
 
  // Unbox
  Debug.Assert(obj != null);

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Object/ObjectWithParameterizedConstructorConverter.Large.cs

@@ -24,6 +24,8 @@ protected sealed override bool ReadAndCacheConstructorArgument(ref ReadStack sta
  if (success && !(arg == null && jsonParameterInfo.IgnoreNullTokensOnRead))
  {
  ((object[])state.Current.CtorArgumentState!.Arguments)[jsonParameterInfo.ClrInfo.Position] = arg!;
+
+ // if this is required property IgnoreNullTokensOnRead will always be false because we don't allow for both to be true
  state.Current.MarkRequiredPropertyAsRead(jsonParameterInfo.MatchingProperty);
  }
 

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Object/ObjectWithParameterizedConstructorConverter.Small.cs

@@ -67,13 +67,12 @@ private static bool TryRead<TArg>(
 
  bool success = converter.TryRead(ref reader, info.PropertyType, info.Options!, ref state, out TArg? value);
 
- if (value == null && jsonParameterInfo.IgnoreNullTokensOnRead)
- {
- arg = (TArg?)info.DefaultValue!; // Use default value specified on parameter, if any.
- }
- else
+ arg = value == null && jsonParameterInfo.IgnoreNullTokensOnRead
+  ? (TArg?)info.DefaultValue! // Use default value specified on parameter, if any.
+ : value!;
+
+ if (success)
  {
- arg = value!;
  state.Current.MarkRequiredPropertyAsRead(jsonParameterInfo.MatchingProperty);
  }
 

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Converters/Object/ObjectWithParameterizedConstructorConverter.cs

@@ -184,7 +184,15 @@ internal sealed override bool OnTryRead(ref Utf8JsonReader reader, Type typeToCo
 
  if (dataExtKey == null)
  {
- jsonPropertyInfo.SetValueAsObject(obj, propValue, ref state);
+ Debug.Assert(jsonPropertyInfo.Set != null);
+
+ if (propValue is not null || !jsonPropertyInfo.IgnoreNullTokensOnRead || default(T) is not null)
+ {
+ jsonPropertyInfo.Set(obj, propValue);
+
+ // if this is required property IgnoreNullTokensOnRead will always be false because we don't allow for both to be true
+ state.Current.MarkRequiredPropertyAsRead(jsonPropertyInfo);
+ }
  }
  else
  {
@@ -211,7 +219,7 @@ internal sealed override bool OnTryRead(ref Utf8JsonReader reader, Type typeToCo
  }
 
  jsonTypeInfo.OnDeserialized?.Invoke(obj);
- jsonTypeInfo.CheckRequiredProperties(ref state);
+ state.Current.ValidateAllRequiredPropertiesAreRead(jsonTypeInfo);
 
  // Unbox
  Debug.Assert(obj != null);
@@ -534,7 +542,7 @@ private void BeginRead(ref ReadStack state, ref Utf8JsonReader reader, JsonSeria
  ThrowHelper.ThrowInvalidOperationException_ConstructorParameterIncompleteBinding(TypeToConvert);
  }
 
- jsonTypeInfo.InitializeRequiredProperties(ref state);
+ state.Current.InitializeRequiredProperties(jsonTypeInfo);
 
  // Set current JsonPropertyInfo to null to avoid conflicts on push.
  state.Current.JsonPropertyInfo = null;

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializer.Read.HandlePropertyName.cs

@@ -139,7 +139,8 @@ internal static void CreateExtensionDataProperty(
  }
 
  extensionData = createObjectForExtensionDataProp();
- jsonPropertyInfo.SetExtensionDictionaryAsObject(obj, extensionData);
+ Debug.Assert(jsonPropertyInfo.Set != null);
+ jsonPropertyInfo.Set(obj, extensionData);
  }
 
  // We don't add the value to the dictionary here because we need to support the read-ahead functionality for Streams.

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Metadata/JsonPropertyInfo.cs

@@ -303,6 +303,11 @@ internal void Configure()
  {
  ThrowHelper.ThrowInvalidOperationException_JsonPropertyRequiredAndExtensionData(this);
  }
+
+ if (IgnoreNullTokensOnRead)
+ {
+ ThrowHelper.ThrowInvalidOperationException_JsonPropertyRequiredAndIgnoreNullValues();
+ }
  }
  }
 
@@ -785,10 +790,6 @@ internal JsonTypeInfo JsonTypeInfo
  }
  }
 
- internal abstract void SetExtensionDictionaryAsObject(object obj, object? extensionDict);
-
- internal abstract void SetValueAsObject(object obj, object? value, ref ReadStack state);
-
  internal bool IsIgnored => _ignoreCondition == JsonIgnoreCondition.Always;
 
  /// <summary>
@@ -850,6 +851,27 @@ public JsonNumberHandling? NumberHandling
  /// </summary>
  internal abstract object? DefaultValue { get; }
 
+ /// <summary>
+ /// Property index on the list of JsonTypeInfo properties.
+ /// Can be used as a unique identifier for i.e. required properties.
+ /// It is set just before property is configured and does not change afterward.
+ /// </summary>
+ internal int Index
+ {
+ get
+ {
+ Debug.Assert(_isConfigured);
+ return _index;
+ }
+ set
+ {
+ Debug.Assert(!_isConfigured);
+ _index = value;
+ }
+ }
+
+ private int _index;
+
  [DebuggerBrowsable(DebuggerBrowsableState.Never)]
  private string DebuggerDisplay => $"PropertyType = {PropertyType}, Name = {Name}, DeclaringType = {DeclaringType}";
  }

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Metadata/JsonPropertyInfoOfT.cs

@@ -339,10 +339,10 @@ internal override bool ReadJsonAndSetMember(object obj, ref ReadStack state, ref
  {
  T? value = default;
  Set!(obj, value!);
- state.Current.MarkRequiredPropertyAsRead(this);
  }
 
  success = true;
+ state.Current.MarkRequiredPropertyAsRead(this);
  }
  else if (TypedEffectiveConverter.CanUseDirectReadOrWrite && state.Current.NumberHandling == null)
  {
@@ -354,10 +354,10 @@ internal override bool ReadJsonAndSetMember(object obj, ref ReadStack state, ref
  // Optimize for internal converters by avoiding the extra call to TryRead.
  T? fastValue = TypedEffectiveConverter.Read(ref reader, PropertyType, Options);
  Set!(obj, fastValue!);
- state.Current.MarkRequiredPropertyAsRead(this);
  }
 
  success = true;
+ state.Current.MarkRequiredPropertyAsRead(this);
  }
  else
  {
@@ -411,25 +411,6 @@ internal override bool ReadJsonAsObject(ref ReadStack state, ref Utf8JsonReader
  return success;
  }
 
- internal sealed override void SetExtensionDictionaryAsObject(object obj, object? extensionDict)
- {
- Debug.Assert(HasSetter);
- T typedValue = (T)extensionDict!;
- Set!(obj, typedValue);
- }
-
- internal sealed override void SetValueAsObject(object obj, object? value, ref ReadStack state)
- {
- Debug.Assert(HasSetter);
-
- if (value is not null || !IgnoreNullTokensOnRead || default(T) is not null)
- {
- T typedValue = (T)value!;
- Set!(obj, typedValue);
- state.Current.MarkRequiredPropertyAsRead(this);
- }
- }
-
  private protected override void ConfigureIgnoreCondition(JsonIgnoreCondition? ignoreCondition)
  {
  switch (ignoreCondition)

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Metadata/JsonTypeInfo.cs

@@ -25,7 +25,11 @@ public abstract partial class JsonTypeInfo
  internal delegate T ParameterizedConstructorDelegate<T, TArg0, TArg1, TArg2, TArg3>(TArg0 arg0, TArg1 arg1, TArg2 arg2, TArg3 arg3);
 
  private JsonPropertyInfoList? _properties;
- internal JsonPropertyInfo[]? RequiredProperties { get; private set; }
+
+ /// <summary>
+ /// Indices of required properties.
+ /// </summary>
+ internal int[]? RequiredPropertiesIndices { get; private set; }
 
  private Action<object>? _onSerializing;
  private Action<object>? _onSerialized;
@@ -270,17 +274,16 @@ public JsonPolymorphismOptions? PolymorphismOptions
  // Avoids having to perform an expensive cast to JsonTypeInfo<T> to check if there is a Serialize method.
  internal bool HasSerializeHandler { get; private protected set; }
 
- // Exception used to throw on deserialization. In some scenarios i.e.:
- // configure would have thrown while initializing properties for source gen but type had SerializeHandler
+ // Configure would normally have thrown why initializing properties for source gen but type had SerializeHandler
  // so it is allowed to be used for fast-path serialization but it will throw if used for metadata-based serialization
- internal Exception? DeserializationException { get; private protected set; }
+ internal bool MetadataSerializationNotSupported { get; private protected set; }
 
  [MethodImpl(MethodImplOptions.AggressiveInlining)]
  internal void ValidateCanBeUsedForMetadataSerialization()
  {
- if (DeserializationException != null)
+ if (MetadataSerializationNotSupported)
  {
- throw DeserializationException;
+ ThrowHelper.ThrowInvalidOperationException_NoMetadataForTypeProperties(Options.TypeInfoResolver, Type);
  }
  }
 
@@ -881,6 +884,7 @@ internal void InitializePropertyCache()
  }
 
  int numberOfRequiredProperties = 0;
+ int propertyIndex = 0;
  foreach (KeyValuePair<string, JsonPropertyInfo> jsonPropertyInfoKv in PropertyCache.List)
  {
  JsonPropertyInfo jsonPropertyInfo = jsonPropertyInfoKv.Value;
@@ -890,25 +894,26 @@ internal void InitializePropertyCache()
  numberOfRequiredProperties++;
  }
 
+ jsonPropertyInfo.Index = propertyIndex++;
  jsonPropertyInfo.EnsureChildOf(this);
  jsonPropertyInfo.EnsureConfigured();
  }
 
  if (numberOfRequiredProperties > 0)
  {
- JsonPropertyInfo[] requiredProperties = new JsonPropertyInfo[numberOfRequiredProperties];
+ int[] requiredPropertiesIndices = new int[numberOfRequiredProperties];
  int idx = 0;
  foreach (KeyValuePair<string, JsonPropertyInfo> jsonPropertyInfoKv in PropertyCache.List)
  {
  JsonPropertyInfo jsonPropertyInfo = jsonPropertyInfoKv.Value;
 
  if (jsonPropertyInfo.IsRequired)
  {
- requiredProperties[idx++] = jsonPropertyInfo;
+ requiredPropertiesIndices[idx++] = jsonPropertyInfo.Index;
  }
  }
 
- RequiredProperties = requiredProperties;
+ RequiredPropertiesIndices = requiredPropertiesIndices;
  }
  }
 
@@ -1027,30 +1032,6 @@ internal JsonPropertyDictionary<JsonPropertyInfo> CreatePropertyCache(int capaci
  return new JsonPropertyDictionary<JsonPropertyInfo>(Options.PropertyNameCaseInsensitive, capacity);
  }
 
- [MethodImpl(MethodImplOptions.AggressiveInlining)]
- internal void InitializeRequiredProperties(ref ReadStack state)
- {
- if (RequiredProperties != null)
- {
- Debug.Assert(state.Current.RequiredPropertiesLeft == null);
- state.Current.RequiredPropertiesLeft = new HashSet<JsonPropertyInfo>(RequiredProperties);
- }
- }
-
- [MethodImpl(MethodImplOptions.AggressiveInlining)]
- internal void CheckRequiredProperties(ref ReadStack state)
- {
- if (RequiredProperties != null)
- {
- Debug.Assert(state.Current.RequiredPropertiesLeft != null);
-
- if (state.Current.RequiredPropertiesLeft.Count != 0)
- {
- ThrowHelper.ThrowJsonException_JsonRequiredPropertyMissing(this, state.Current.RequiredPropertiesLeft);
- }
- }
- }
-
  private static JsonParameterInfo CreateConstructorParameter(
  JsonParameterInfoValues parameterInfo,
  JsonPropertyInfo jsonPropertyInfo,

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/Metadata/SourceGenJsonTypeInfoOfT.cs

@@ -113,7 +113,7 @@ internal override JsonParameterInfoValues[] GetParameterInfoValues()
  }
 
  array = Array.Empty<JsonParameterInfoValues>();
- DeserializationException = ThrowHelper.GetInvalidOperationException_NoMetadataForTypeProperties(Options.TypeInfoResolver, Type);
+ MetadataSerializationNotSupported = true;
  }
 
  return array;
@@ -149,7 +149,7 @@ internal override void LateAddProperties()
  ThrowHelper.ThrowInvalidOperationException_NoMetadataForTypeProperties(Options.TypeInfoResolver, Type);
  }
 
- DeserializationException = ThrowHelper.GetInvalidOperationException_NoMetadataForTypeProperties(Options.TypeInfoResolver, Type);
+ MetadataSerializationNotSupported = true;
  return;
  }
 

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/ReadStackFrame.cs

@@ -3,6 +3,7 @@
 
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Text.Json.Serialization;
 using System.Text.Json.Serialization.Metadata;
@@ -67,7 +68,7 @@ public JsonTypeInfo BaseJsonTypeInfo
  public JsonNumberHandling? NumberHandling;
 
  // Required properties left
- public HashSet<JsonPropertyInfo>? RequiredPropertiesLeft;
+ public HashSet<int>? RequiredPropertiesLeft;
 
  public void EndConstructorParameter()
  {
@@ -110,12 +111,37 @@ public bool IsProcessingEnumerable()
  return (JsonTypeInfo.PropertyInfoForTypeInfo.ConverterStrategy & ConverterStrategy.Enumerable) != 0;
  }
 
+ [MethodImpl(MethodImplOptions.AggressiveInlining)]
  public void MarkRequiredPropertyAsRead(JsonPropertyInfo propertyInfo)
  {
  if (propertyInfo.IsRequired)
  {
  Debug.Assert(RequiredPropertiesLeft != null);
- RequiredPropertiesLeft.Remove(propertyInfo);
+ RequiredPropertiesLeft.Remove(propertyInfo.Index);
+ }
+ }
+
+ [MethodImpl(MethodImplOptions.AggressiveInlining)]
+ internal void InitializeRequiredProperties(JsonTypeInfo typeInfo)
+ {
+ if (typeInfo.RequiredPropertiesIndices != null)
+ {
+ Debug.Assert(RequiredPropertiesLeft == null);
+ RequiredPropertiesLeft = new HashSet<int>(typeInfo.RequiredPropertiesIndices);
+ }
+ }
+
+ [MethodImpl(MethodImplOptions.AggressiveInlining)]
+ internal void ValidateAllRequiredPropertiesAreRead(JsonTypeInfo typeInfo)
+ {
+ if (typeInfo.RequiredPropertiesIndices != null)
+ {
+ Debug.Assert(RequiredPropertiesLeft != null);
+
+ if (RequiredPropertiesLeft.Count != 0)
+ {
+ ThrowHelper.ThrowJsonException_JsonRequiredPropertyMissing(typeInfo, RequiredPropertiesLeft);
+ }
  }
  }