Add Dictionary with non-string keys to System.Text.Json

MediaBrowser.Common/Json/Converters/JsonNonStringKeyDictionaryConverter.cs

@@ -0,0 +1,79 @@
+#nullable enable
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Reflection;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace MediaBrowser.Common.Json.Converters
+{
+    /// <summary>
+    /// Converter for Dictionaries without string key.
+    /// TODO This can be removed when System.Text.Json supports Dictionaries with non-string keys.
+    /// </summary>
+    /// <typeparam name="TKey">Type of key.</typeparam>
+    /// <typeparam name="TValue">Type of value.</typeparam>
+    internal sealed class JsonNonStringKeyDictionaryConverter<TKey, TValue> : JsonConverter<IDictionary<TKey, TValue>>
+    {
+        /// <summary>
+        /// Read JSON.
+        /// </summary>
+        /// <param name="reader">The Utf8JsonReader.</param>
+        /// <param name="typeToConvert">The type to convert.</param>
+        /// <param name="options">The json serializer options.</param>
+        /// <returns>Typed dictionary.</returns>
+        /// <exception cref="NotSupportedException"></exception>
+        public override IDictionary<TKey, TValue> Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            var convertedType = typeof(Dictionary<,>).MakeGenericType(typeof(string), typeToConvert.GenericTypeArguments[1]);
+            var value = JsonSerializer.Deserialize(ref reader, convertedType, options);
+            var instance = (Dictionary<TKey, TValue>)Activator.CreateInstance(
+                typeToConvert,
+                BindingFlags.Instance | BindingFlags.Public,
+                null,
+                null,
+                CultureInfo.CurrentCulture);
+            var enumerator = (IEnumerator)convertedType.GetMethod("GetEnumerator")!.Invoke(value, null);
+            var parse = typeof(TKey).GetMethod(
+                "Parse", 
+                0, 
+                BindingFlags.Public | BindingFlags.Static, 
+                null, 
+                CallingConventions.Any, 
+                new[] { typeof(string) }, 
+                null);
+            if (parse == null)
+            {
+                throw new NotSupportedException($"{typeof(TKey)} as TKey in IDictionary<TKey, TValue> is not supported.");
+            }
+            
+            while (enumerator.MoveNext())
+            {
+                var element = (KeyValuePair<string?, TValue>)enumerator.Current;
+                instance.Add((TKey)parse.Invoke(null, new[] { (object?) element.Key }), element.Value);
+            }
+            
+            return instance;
+        }
+
+        /// <summary>
+        /// Write dictionary as Json.
+        /// </summary>
+        /// <param name="writer">The Utf8JsonWriter.</param>
+        /// <param name="value">The dictionary value.</param>
+        /// <param name="options">The Json serializer options.</param>
+        public override void Write(Utf8JsonWriter writer, IDictionary<TKey, TValue> value, JsonSerializerOptions options)
+        {
+            var convertedDictionary = new Dictionary<string?, TValue>(value.Count);
+            foreach (var (k, v) in value)
+            {
+                convertedDictionary[k?.ToString()] = v;
+            }
+            JsonSerializer.Serialize(writer, convertedDictionary, options);
+            convertedDictionary.Clear();
+        }
+    }
+}