Switch to System.Text.Json

Benchmarks/Schema.NET.Benchmarks/SchemaBenchmarkBase.cs

@@ -1,9 +1,9 @@
 namespace Schema.NET.Benchmarks
 {
     using System;
+    using System.Text.Json;
     using BenchmarkDotNet.Attributes;
     using BenchmarkDotNet.Jobs;
-    using Newtonsoft.Json;
 
     [KeepBenchmarkFiles]
     [MemoryDiagnoser]
@@ -36,6 +36,6 @@ public virtual void Setup()
         public string Serialize() => this.Thing.ToString();
 
         [Benchmark]
-        public object? Deserialize() => JsonConvert.DeserializeObject(this.SerializedThing, this.ThingType);
+        public object? Deserialize() => JsonSerializer.Deserialize(this.SerializedThing, this.ThingType);
     }
 }

Schema.NET.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
-VisualStudioVersion = 17.0.31423.177
+VisualStudioVersion = 17.0.31612.314
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Source", "Source", "{719809C2-A551-4C4A-9EFD-B10FB5E35BC0}"
 	ProjectSection(SolutionItems) = preProject
@@ -94,6 +94,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Schema.NET.Pending", "Sourc
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Common", "Common", "{AF228B8A-7290-4E26-8506-934C290C6AE3}"
 	ProjectSection(SolutionItems) = preProject
+		Source\Common\Constants.cs = Source\Common\Constants.cs
 		Source\Common\ContactType.cs = Source\Common\ContactType.cs
 		Source\Common\ContextJsonConverter.cs = Source\Common\ContextJsonConverter.cs
 		Source\Common\DateTimeHelper.cs = Source\Common\DateTimeHelper.cs
@@ -106,6 +107,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Common", "Common", "{AF228B
 		Source\Common\JsonLdObject.cs = Source\Common\JsonLdObject.cs
 		Source\Common\OneOrMany{T}.cs = Source\Common\OneOrMany{T}.cs
 		Source\Common\PropertyValueSpecification.Partial.cs = Source\Common\PropertyValueSpecification.Partial.cs
+		Source\Common\SchemaEnumJsonConverter{T}.cs = Source\Common\SchemaEnumJsonConverter{T}.cs
 		Source\Common\SchemaSerializer.cs = Source\Common\SchemaSerializer.cs
 		Source\Common\Thing.Partial.cs = Source\Common\Thing.Partial.cs
 		Source\Common\TimeSpanToISO8601DurationValuesJsonConverter.cs = Source\Common\TimeSpanToISO8601DurationValuesJsonConverter.cs

Source/Common/Constants.cs

@@ -0,0 +1,18 @@
+namespace Schema.NET
+{
+    /// <summary>
+    /// Various constants for use within Schema.NET
+    /// </summary>
+    public static class Constants
+    {
+        /// <summary>
+        /// The HTTPS URL for Schema.org, excluding trailing slash.
+        /// </summary>
+        public const string HttpsSchemaOrgUrl = "https://schema.org";
+
+        /// <summary>
+        /// The HTTP URL for Schema.org, excluding trailing slash.
+        /// </summary>
+        public const string HttpSchemaOrgUrl = "http://schema.org";
+    }
+}

Source/Common/ContextJsonConverter.cs

@@ -1,8 +1,8 @@
 namespace Schema.NET
 {
     using System;
-    using Newtonsoft.Json;
-    using Newtonsoft.Json.Linq;
+    using System.Text.Json;
+    using System.Text.Json.Serialization;
 
     /// <summary>
     /// Converts a <see cref="JsonLdContext"/> object to and from JSON.
@@ -11,96 +11,81 @@ namespace Schema.NET
     public class ContextJsonConverter : JsonConverter<JsonLdContext>
     {
         /// <inheritdoc />
-        public override JsonLdContext ReadJson(JsonReader reader, Type objectType, JsonLdContext? existingValue, bool hasExistingValue, JsonSerializer serializer)
+        public override JsonLdContext Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
         {
 #if NET6_0_OR_GREATER
-            ArgumentNullException.ThrowIfNull(reader);
-            ArgumentNullException.ThrowIfNull(objectType);
-            if (hasExistingValue)
-            {
-                ArgumentNullException.ThrowIfNull(existingValue);
-            }
-
-            ArgumentNullException.ThrowIfNull(serializer);
+            ArgumentNullException.ThrowIfNull(typeToConvert);
+            ArgumentNullException.ThrowIfNull(options);
 #else
-            if (reader is null)
-            {
-                throw new ArgumentNullException(nameof(reader));
-            }
-
-            if (objectType is null)
-            {
-                throw new ArgumentNullException(nameof(objectType));
-            }
-
-            if (hasExistingValue && existingValue is null)
+            if (typeToConvert is null)
             {
-                throw new ArgumentNullException(nameof(existingValue));
+                throw new ArgumentNullException(nameof(typeToConvert));
             }
 
-            if (serializer is null)
+            if (options is null)
             {
-                throw new ArgumentNullException(nameof(serializer));
+                throw new ArgumentNullException(nameof(options));
             }
 #endif
+            var context = new JsonLdContext();
 
-            var context = hasExistingValue ? existingValue! : new JsonLdContext();
-
-            string? name;
-            string? language;
-            if (reader.TokenType == JsonToken.String)
+            string? name = null;
+            string? language = null;
+            if (reader.TokenType == JsonTokenType.String)
             {
-                name = (string?)reader.Value;
-                language = null;
+                name = reader.GetString();
             }
-            else if (reader.TokenType == JsonToken.StartObject)
+            else if (reader.TokenType == JsonTokenType.StartObject)
             {
-                var o = JObject.Load(reader);
+                var document = JsonDocument.ParseValue(ref reader);
 
-                var nameProperty = o.Property("name", StringComparison.OrdinalIgnoreCase);
-                name = nameProperty?.Value?.ToString() ?? "https://schema.org";
+                if (document.RootElement.TryGetProperty("name", out var nameElement))
+                {
+                    name = nameElement.GetString() ?? Constants.HttpsSchemaOrgUrl;
+                }
 
-                var languageProperty = o.Property("@language", StringComparison.OrdinalIgnoreCase);
-                language = languageProperty?.Value?.ToString();
+                if (document.RootElement.TryGetProperty("@language", out var languageElement))
+                {
+                    language = languageElement.GetString();
+                }
             }
             else
             {
-                var a = JArray.Load(reader);
+                var array = JsonDocument.ParseValue(ref reader).RootElement.EnumerateArray();
 
-                name = language = null;
-                foreach (var entry in a)
+                foreach (var entry in array)
                 {
-                    if (entry.Type == JTokenType.String)
+                    if (entry.ValueKind == JsonValueKind.String)
                     {
-                        name ??= (string?)entry;
+                        name ??= entry.GetString();
                     }
-                    else
+                    else if (entry.ValueKind == JsonValueKind.Object)
                     {
-                        var o = (JObject)entry;
-
-                        var nameProperty = o.Property("name", StringComparison.OrdinalIgnoreCase);
-                        name ??= nameProperty?.Value?.ToString() ?? "https://schema.org";
-
-                        var languageProperty = o.Property("@language", StringComparison.OrdinalIgnoreCase);
-                        language ??= languageProperty?.Value?.ToString();
+                        if (entry.TryGetProperty("name", out var nameElement))
+                        {
+                            name ??= nameElement.GetString() ?? Constants.HttpsSchemaOrgUrl;
+                        }
+
+                        if (entry.TryGetProperty("@language", out var languageElement))
+                        {
+                            language ??= languageElement.GetString();
+                        }
                     }
                 }
             }
 
-#pragma warning disable CA1062 // Validate arguments of public methods
             context.Name = name;
             context.Language = language;
-#pragma warning restore CA1062 // Validate arguments of public methods
             return context;
         }
 
         /// <inheritdoc />
-        public override void WriteJson(JsonWriter writer, JsonLdContext? value, JsonSerializer serializer)
+        public override void Write(Utf8JsonWriter writer, JsonLdContext value, JsonSerializerOptions options)
         {
 #if NET6_0_OR_GREATER
             ArgumentNullException.ThrowIfNull(writer);
             ArgumentNullException.ThrowIfNull(value);
-            ArgumentNullException.ThrowIfNull(serializer);
+            ArgumentNullException.ThrowIfNull(options);
 #else
             if (writer is null)
             {
@@ -112,23 +97,23 @@ public override void WriteJson(JsonWriter writer, JsonLdContext? value, JsonSeri
                 throw new ArgumentNullException(nameof(value));
             }
 
-            if (serializer is null)
+            if (options is null)
             {
-                throw new ArgumentNullException(nameof(serializer));
+                throw new ArgumentNullException(nameof(options));
             }
 #endif
 
             if (string.IsNullOrWhiteSpace(value.Language))
             {
-                writer.WriteValue(value.Name);
+                writer.WriteStringValue(value.Name);
             }
             else
             {
                 writer.WriteStartObject();
                 writer.WritePropertyName("name");
-                writer.WriteValue(value.Name);
+                writer.WriteStringValue(value.Name);
                 writer.WritePropertyName("@language");
-                writer.WriteValue(value.Language);
+                writer.WriteStringValue(value.Language);
                 writer.WriteEndObject();
             }
         }

Source/Common/DateTimeToIso8601DateValuesJsonConverter.cs

@@ -2,7 +2,8 @@ namespace Schema.NET
 {
     using System;
     using System.Globalization;
-    using Newtonsoft.Json;
+    using System.Text.Json;
+    using System.Text.Json.Serialization;
 
     /// <summary>
     /// Converts an <see cref="IValues"/> object to JSON. If the <see cref="IValues"/> contains a
@@ -17,31 +18,31 @@ public class DateTimeToIso8601DateValuesJsonConverter : ValuesJsonConverter
         /// </summary>
         /// <param name="writer">The JSON writer.</param>
         /// <param name="value">The value to write.</param>
-        /// <param name="serializer">The JSON serializer.</param>
-        public override void WriteObject(JsonWriter writer, object? value, JsonSerializer serializer)
+        /// <param name="options">The JSON serializer options.</param>
+        public override void WriteObject(Utf8JsonWriter writer, object? value, JsonSerializerOptions options)
         {
 #if NET6_0_OR_GREATER
             ArgumentNullException.ThrowIfNull(writer);
-            ArgumentNullException.ThrowIfNull(serializer);
+            ArgumentNullException.ThrowIfNull(options);
 #else
             if (writer is null)
             {
                 throw new ArgumentNullException(nameof(writer));
             }
 
-            if (serializer is null)
+            if (options is null)
             {
-                throw new ArgumentNullException(nameof(serializer));
+                throw new ArgumentNullException(nameof(options));
             }
 #endif
 
             if (value is DateTime dateTimeType)
             {
-                writer.WriteValue(dateTimeType.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture));
+                writer.WriteStringValue(dateTimeType.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture));
             }
             else
             {
-                base.WriteObject(writer, value, serializer);
+                base.WriteObject(writer, value, options);
             }
         }
     }

Source/Common/EnumHelper.cs

@@ -1,6 +1,7 @@
 namespace Schema.NET
 {
     using System;
+    using System.Diagnostics;
     using System.Diagnostics.CodeAnalysis;
 
     /// <summary>
@@ -43,5 +44,49 @@ public static bool TryParse(
 #pragma warning restore IDE0022 // Use expression body for methods
 #endif
         }
+
+        /// <summary>
+        /// Converts the Schema URI representation of the enum type to an equivalent enumerated object.
+        /// </summary>
+        /// <param name="enumType">The enum type to use for parsing.</param>
+        /// <param name="value">The string representation of the name or numeric value of one or more enumerated constants.</param>
+        /// <param name="result">When this method returns true, an object containing an enumeration constant representing the parsed value.</param>
+        /// <returns><see langword="true"/> if the conversion succeeded; <see langword="false"/> otherwise.</returns>
+        public static bool TryParseEnumFromSchemaUri(
+            Type enumType,
+#if NETCOREAPP3_1_OR_GREATER
+            [NotNullWhen(true)]
+#endif
+            string? value,
+            out object? result)
+        {
+            string? enumString;
+            if (value is not null && value.StartsWith(Constants.HttpSchemaOrgUrl, StringComparison.OrdinalIgnoreCase))
+            {
+#pragma warning disable IDE0057 // Use range operator. Need to multi-target.
+                enumString = value.Substring(Constants.HttpSchemaOrgUrl.Length + 1);
+#pragma warning restore IDE0057 // Use range operator. Need to multi-target.
+            }
+            else if (value is not null && value.StartsWith(Constants.HttpsSchemaOrgUrl, StringComparison.OrdinalIgnoreCase))
+            {
+#pragma warning disable IDE0057 // Use range operator. Need to multi-target.
+                enumString = value.Substring(Constants.HttpsSchemaOrgUrl.Length + 1);
+#pragma warning restore IDE0057 // Use range operator. Need to multi-target.
+            }
+            else
+            {
+                enumString = value;
+            }
+
+            if (TryParse(enumType, enumString, out result))
+            {
+                return true;
+            }
+            else
+            {
+                Debug.WriteLine($"Unable to parse enumeration of type {enumType.FullName} with value {enumString}.");
+                return false;
+            }
+        }
     }
 }

Source/Common/JsonLdContext.cs

@@ -1,7 +1,7 @@
 namespace Schema.NET
 {
     using System;
-    using System.Runtime.Serialization;
+    using System.Text.Json.Serialization;
 
     /// <summary>
     /// The @context for a JSON-LD document.
@@ -12,13 +12,15 @@ public class JsonLdContext : IEquatable<JsonLdContext>
         /// <summary>
         /// Gets or sets the name.
         /// </summary>
-        [DataMember(Name = "name", Order = 0)]
-        public string? Name { get; set; } = "https://schema.org";
+        [JsonPropertyName("name")]
+        [JsonPropertyOrder(0)]
+        public string? Name { get; set; } = Constants.HttpsSchemaOrgUrl;
 
         /// <summary>
         /// Gets or sets the language.
         /// </summary>
-        [DataMember(Name = "@language", Order = 1)]
+        [JsonPropertyName("@language")]
+        [JsonPropertyOrder(1)]
         public string? Language { get; set; }
 
         /// <summary>