Nullable ref types (and some schema things)

Json.More/EnumStringConverter.cs

@@ -33,12 +33,32 @@ namespace Json.More
 	public class EnumStringConverter<T> : JsonConverter<T>
 		where T : Enum
 	{
-		private static Dictionary<string, T> _readValues;
-		private static Dictionary<T, string> _writeValues;
-		private static Func<T, T, T> _aggregator;
+		private static Dictionary<string, T>? _readValues;
+		private static Dictionary<T, string>? _writeValues;
+		private static Func<T, T, T>? _aggregator;
 		// ReSharper disable once StaticMemberInGenericType
 		private static readonly object _lock = new object();
 
+		private static Dictionary<string, T> ReadValues
+		{
+			get
+			{
+				EnsureMap();
+				return _readValues!;
+			}
+		}
+
+		private static Dictionary<T, string> WriteValues
+		{
+			get
+			{
+				EnsureMap();
+				return _writeValues!;
+			}
+		}
+
+		private static Func<T, T, T> Aggregator => _aggregator ??= BuildAggregator();
+
 		/// <summary>Reads and converts the JSON to type <typeparamref name="T" />.</summary>
 		/// <param name="reader">The reader.</param>
 		/// <param name="typeToConvert">The type to convert.</param>
@@ -60,22 +80,22 @@ public override T Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerial
 					{
 						str = reader.GetString();
 
-						if (!_readValues.TryGetValue(str, out var immediate))
+						if (!ReadValues.TryGetValue(str, out var immediate))
 							throw new JsonException($"Could not find appropriate value for {str} in type {typeToConvert.Name}");
 
 						values.Add(immediate);
 						reader.Read();
 					}
 					reader.Read(); // waste the end array
 
-					return ToCombined(values);
+					return values.Aggregate(Aggregator);
 				}
 				throw new JsonException("Expected string");
 			}
 
 			str = reader.GetString();
 
-			return _readValues.TryGetValue(str, out var value)
+			return ReadValues.TryGetValue(str, out var value)
 				? value
 				: throw new JsonException($"Could not find appropriate value for {str} in type {typeToConvert.Name}");
 		}
@@ -88,43 +108,38 @@ public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions
 		{
 			EnsureMap();
 
-			if (typeof(T).GetCustomAttribute<FlagsAttribute>() != null && !_writeValues.ContainsKey(value))
+			if (typeof(T).GetCustomAttribute<FlagsAttribute>() != null && !WriteValues.ContainsKey(value))
 			{
 				writer.WriteStartArray();
-				foreach (var name in _writeValues.Keys)
+				foreach (var name in WriteValues.Keys)
 				{
 					if (value.HasFlag(name))
-						writer.WriteStringValue(_writeValues[name]);
+						writer.WriteStringValue(WriteValues[name]);
 				}
 				writer.WriteEndArray();
 				return;
 			}
 
-			writer.WriteStringValue(_writeValues[value]);
+			writer.WriteStringValue(WriteValues[value]);
 		}
 
-		private static T ToCombined(IEnumerable<T> list)
+		private static Func<T, T, T> BuildAggregator()
 		{
-			if (_aggregator == null)
-			{
-				var underlyingType = Enum.GetUnderlyingType(typeof(T));
-				var currentParameter = Expression.Parameter(typeof(T), "current");
-				var nextParameter = Expression.Parameter(typeof(T), "next");
-
-				_aggregator = Expression.Lambda<Func<T, T, T>>(
-					Expression.Convert(
-						Expression.Or(
-							Expression.Convert(currentParameter, underlyingType),
-							Expression.Convert(nextParameter, underlyingType)
-						),
-						typeof(T)
+			var underlyingType = Enum.GetUnderlyingType(typeof(T));
+			var currentParameter = Expression.Parameter(typeof(T), "current");
+			var nextParameter = Expression.Parameter(typeof(T), "next");
+
+			return Expression.Lambda<Func<T, T, T>>(
+				Expression.Convert(
+					Expression.Or(
+						Expression.Convert(currentParameter, underlyingType),
+						Expression.Convert(nextParameter, underlyingType)
 					),
-					currentParameter,
-					nextParameter
-				).Compile();
-			}
-
-			return list.Aggregate(_aggregator);
+					typeof(T)
+				),
+				currentParameter,
+				nextParameter
+			).Compile();
 		}
 
 		private static void EnsureMap()

Json.More/Json.More.csproj

@@ -4,7 +4,7 @@
     <TargetFramework>netstandard2.0</TargetFramework>
     <PackageId>Json.More.Net</PackageId>
     <Authors>Greg Dennis</Authors>
-    <Version>1.3.0</Version>
+    <Version>1.4.0</Version>
     <Description>Provides extended functionality for the System.Text.Json namespace.</Description>
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <PackageProjectUrl>https://github.com/gregsdennis/json-everything</PackageProjectUrl>
@@ -14,7 +14,7 @@
     <PackageReleaseNotes>https://gregsdennis.github.io/json-everything/release-notes/json-more.html</PackageReleaseNotes>
     <LangVersion>latest</LangVersion>
     <AssemblyVersion>1.0.0.0</AssemblyVersion>
-    <FileVersion>1.3.0.0</FileVersion>
+    <FileVersion>1.4.0.0</FileVersion>
     <DocumentationFile>Json.More.xml</DocumentationFile>
     <PackageIcon>json-logo-256.png</PackageIcon>
 	  <IncludeSymbols>true</IncludeSymbols>
@@ -23,6 +23,7 @@
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>../json-everything.snk</AssemblyOriginatorKeyFile>
+	  <Nullable>enable</Nullable>
    </PropertyGroup>
 
   <ItemGroup>
@@ -31,6 +32,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <None Include="..\docs_source\release-notes\json-more.md" Link="json-more.md" />
     <None Include="..\LICENSE">
       <Pack>True</Pack>
       <PackagePath></PackagePath>

Json.More/JsonDocumentExtensions.cs

@@ -25,7 +25,7 @@ public static bool IsEquivalentTo(this JsonDocument a, JsonDocument b)
 		/// <param name="value">The value to convert.</param>
 		/// <param name="options">(optional) JSON serialization options.</param>
 		/// <returns>A <see cref="JsonDocument"/> representing the vale.</returns>
-		public static JsonDocument ToJsonDocument<T>(this T value, JsonSerializerOptions options = null)
+		public static JsonDocument ToJsonDocument<T>(this T value, JsonSerializerOptions? options = null)
 		{
 			return JsonDocument.Parse(JsonSerializer.Serialize(value, options));
 		}

Json.More/JsonElementExtensions.cs

@@ -52,6 +52,78 @@ public static bool IsEquivalentTo(this JsonElement a, JsonElement b)
 			}
 		}
 
+		// source: https://stackoverflow.com/a/60592310/878701, modified for netstandard2.0
+		// license: https://creativecommons.org/licenses/by-sa/4.0/
+		/// <summary>
+		/// Generate a consistent JSON-value-based hash code for the element.
+		/// </summary>
+		/// <param name="element">The element.</param>
+		/// <param name="maxHashDepth">Maximum depth to calculate.  Default is -1 which utilizes the entire structure without limitation.</param>
+		/// <returns>The hash code.</returns>
+		/// <remarks>
+		/// See the following for discussion on why the default implementation is insufficient:
+		///
+		/// - https://github.com/gregsdennis/json-everything/issues/76
+		/// - https://github.com/dotnet/runtime/issues/33388
+		/// </remarks>
+		public static int GetEquivalenceHashCode(this JsonElement element, int maxHashDepth = -1)
+		{
+			static void Add(ref int current, object? newValue)
+			{
+				unchecked
+				{
+					current = current * 397 ^ (newValue?.GetHashCode() ?? 0);
+				}
+			}
+
+			void ComputeHashCode(JsonElement obj, ref int current, int depth)
+			{
+				Add(ref current, obj.ValueKind);
+
+				switch (obj.ValueKind)
+				{
+					case JsonValueKind.Null:
+					case JsonValueKind.True:
+					case JsonValueKind.False:
+					case JsonValueKind.Undefined:
+						break;
+
+					case JsonValueKind.Number:
+						Add(ref current, obj.GetRawText());
+						break;
+
+					case JsonValueKind.String:
+						Add(ref current, obj.GetString());
+						break;
+
+					case JsonValueKind.Array:
+						if (depth != maxHashDepth)
+							foreach (var item in obj.EnumerateArray())
+								ComputeHashCode(item, ref current, depth + 1);
+						else
+							Add(ref current, obj.GetArrayLength());
+						break;
+
+					case JsonValueKind.Object:
+						foreach (var property in obj.EnumerateObject().OrderBy(p => p.Name, StringComparer.Ordinal))
+						{
+							Add(ref current, property.Name);
+							if (depth != maxHashDepth)
+								ComputeHashCode(property.Value, ref current, depth + 1);
+						}
+						break;
+
+					default:
+						throw new JsonException($"Unknown JsonValueKind {obj.ValueKind}");
+				}
+			}
+
+			var hash = 0;
+			ComputeHashCode(element, ref hash, 0);
+			return hash;
+
+		}
+
 		/// <summary>
 		/// Just a shortcut for calling `JsonSerializer.Serialize()` because `.ToString()` doesn't do what you might expect.
 		/// </summary>
@@ -150,12 +222,12 @@ public static JsonElement AsJsonElement(this float value)
 		}
 
 		/// <summary>
-		/// Converts a <see cref="string"/> to a <see cref="JsonElement"/>.
+		/// Converts a <see cref="string"/> to a <see cref="JsonElement"/>.  Can also be used to get a `null` element.
 		/// </summary>
 		/// <param name="value">The value to convert.</param>
 		/// <returns>A <see cref="JsonElement"/> representing the value.</returns>
 		/// <remarks>This is a workaround for lack of native support in the System.Text.Json namespace.</remarks>
-		public static JsonElement AsJsonElement(this string value)
+		public static JsonElement AsJsonElement(this string? value)
 		{
 			var doc = JsonDocument.Parse(JsonSerializer.Serialize(value));
 			return doc.RootElement;

JsonLogic/JsonElementExtensions.cs

@@ -22,7 +22,7 @@ public static bool IsTruthy(this JsonElement element)
 			};
 		}
 
-		public static string Stringify(this JsonElement element)
+		public static string? Stringify(this JsonElement element)
 		{
 			return element.ValueKind switch
 			{
@@ -58,7 +58,7 @@ public static IEnumerable<JsonElement> Flatten(this JsonElement root)
 		// Ported from: https://github.com/marvindv/jsonlogic_rs/blob/b2ad93af575f19c6b220a6a54d599e104e72a630/src/operators/logic.rs#L33
 		public static bool LooseEquals(this JsonElement a, JsonElement b)
 		{
-			string CoerceArrayToString(JsonElement array) => string.Join(",", array.EnumerateArray().Select(e => e.ToJsonString()));
+			static string CoerceArrayToString(JsonElement array) => string.Join(",", array.EnumerateArray().Select(e => e.ToJsonString()));
 
 			return (a.ValueKind, b.ValueKind) switch
 			{

JsonLogic/JsonLogic.csproj

@@ -14,24 +14,26 @@
     <PackageTags>json logic json-logic jsonlogic</PackageTags>
     <PackageReleaseNotes>https://gregsdennis.github.io/json-everything/release-notes/json-logic.html</PackageReleaseNotes>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
-    <Version>1.2.0</Version>
+    <Version>1.2.1</Version>
     <AssemblyVersion>1.0.0.0</AssemblyVersion>
-    <FileVersion>1.2.0.0</FileVersion>
+    <FileVersion>1.2.1.0</FileVersion>
     <DocumentationFile>JsonLogic.xml</DocumentationFile>
 	  <IncludeSymbols>true</IncludeSymbols>
 	  <SymbolPackageFormat>snupkg</SymbolPackageFormat>
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <EmbedUntrackedSources>true</EmbedUntrackedSources>
 	  <SignAssembly>true</SignAssembly>
 	  <AssemblyOriginatorKeyFile>../json-everything.snk</AssemblyOriginatorKeyFile>
+		<Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="System.Text.Json" Version="4.7.2" />
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
   </ItemGroup>
 
   <ItemGroup>
+    <None Include="..\docs_source\release-notes\json-logic.md" Link="json-logic.md" />
     <None Include="..\LICENSE">
       <Pack>True</Pack>
       <PackagePath></PackagePath>

JsonLogic/Rule.cs

@@ -34,7 +34,7 @@ public abstract class Rule
 		/// Casts a `string` value to a <see cref="LiteralRule"/>.  Can also be used to create a `null` JSON literal.
 		/// </summary>
 		/// <param name="value">The value.</param>
-		public static implicit operator Rule(string value) => new LiteralRule(value);
+		public static implicit operator Rule(string? value) => new LiteralRule(value);
 		/// <summary>
 		/// Casts a `bool` value to a <see cref="LiteralRule"/>.
 		/// </summary>
@@ -86,7 +86,7 @@ public override Rule Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSer
 
 			var ruleType = RuleRegistry.GetRule(ruleInfo.Key);
 
-			var value = ruleInfo.Value ?? new ArgumentCollection((Rule) null);
+			var value = ruleInfo.Value ?? new ArgumentCollection((Rule?) null);
 
 			return (Rule) Activator.CreateInstance(ruleType,
 				value.Cast<object>()
@@ -107,9 +107,9 @@ public override void Write(Utf8JsonWriter writer, Rule value, JsonSerializerOpti
 	[JsonConverter(typeof(ArgumentCollectionConverter))]
 	internal class ArgumentCollection : List<Rule>
 	{
-		public ArgumentCollection(Rule single)
+		public ArgumentCollection(Rule? single)
 		{
-			Add(single);
+			Add(single!);
 		}
 
 		public ArgumentCollection(IEnumerable<Rule> components)

JsonLogic/RuleRegistry.cs

@@ -22,7 +22,7 @@ public static class RuleRegistry
 		/// </summary>
 		/// <param name="identifier">The identifier.</param>
 		/// <returns>The <see cref="Type"/> of the rule.</returns>
-		public static Type GetRule(string identifier)
+		public static Type? GetRule(string identifier)
 		{
 			return _rules.TryGetValue(identifier, out var t) ? t : null;
 		}

JsonLogic/Rules/IfRule.cs

@@ -22,7 +22,7 @@ public override JsonElement Apply(JsonElement data)
 			switch (_components.Count)
 			{
 				case 0:
-					return ((string) null).AsJsonElement();
+					return ((string?) null).AsJsonElement();
 				case 1:
 					return _components[0].Apply(data);
 				case 2:
@@ -31,7 +31,7 @@ public override JsonElement Apply(JsonElement data)
 
 					return condition
 						? thenResult.Apply(data)
-						: ((string) null).AsJsonElement();
+						: ((string?) null).AsJsonElement();
 				default:
 					var currentCondition = _components[0];
 					var currentTrueResult = _components[1];
@@ -44,7 +44,7 @@ public override JsonElement Apply(JsonElement data)
 						if (condition)
 							return currentTrueResult.Apply(data);
 
-						if (elseIndex == _components.Count) return ((string) null).AsJsonElement();
+						if (elseIndex == _components.Count) return ((string?) null).AsJsonElement();
 
 						currentCondition = _components[elseIndex++];