Fix API break: public API must not expose JsonElement objects

This changes deserialization to the way how it was with
Json.Net: Only .net primitive types are exposed publicly

Author: softworkz

src/ElectronNET.API/API/IpcMain.cs

@@ -1,19 +1,32 @@
-using ElectronNET.API.Serialization;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text.Json;
-using System.Threading.Tasks;
-
 namespace ElectronNET.API
 {
+    using System;
+    using System.Diagnostics;
+    using System.Linq;
+    using System.Text.Json;
+    using System.Text.Json.Serialization;
+    using System.Threading.Tasks;
+    using ElectronNET.Serialization;
+
     /// <summary>
     /// Communicate asynchronously from the main process to renderer processes.
     /// </summary>
     public sealed class IpcMain
     {
         private static IpcMain _ipcMain;
         private static object _syncRoot = new object();
+        private static readonly JsonSerializerOptions BoxedObjectSerializationOptions = new JsonSerializerOptions
+        {
+            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+            DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
+            WriteIndented = false,
+            Converters =
+            {
+                new JsonStringEnumConverter(JsonNamingPolicy.CamelCase),
+                new JsonToBoxedPrimitivesConverter(),
+            }
+        };
+
 
         internal IpcMain()
         {
@@ -65,6 +78,7 @@ public async Task On(string channel, Action<object> listener)
 
         private static List<object> FormatArguments(JsonElement args)
         {
+            var objectArray = args.Deserialize<object[]>(BoxedObjectSerializationOptions).ToList();
             var objectArray = args.Deserialize<object[]>(ElectronJson.Options).ToList();
             objectArray.RemoveAll(item => item is null);
             return objectArray;

src/ElectronNET.API/Serialization/JsonToBoxedPrimitivesConverter.cs

@@ -0,0 +1,126 @@
+namespace ElectronNET.Serialization
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Text.Json;
+    using System.Text.Json.Serialization;
+
+    public sealed class JsonToBoxedPrimitivesConverter : JsonConverter<object>
+    {
+        public override object Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            return ReadValue(ref reader);
+        }
+
+        private static object ReadValue(ref Utf8JsonReader r)
+        {
+            switch (r.TokenType)
+            {
+                case JsonTokenType.StartObject:
+
+                    var obj = new Dictionary<string, object>();
+                    while (r.Read())
+                    {
+                        if (r.TokenType == JsonTokenType.EndObject)
+                        {
+                            return obj;
+                        }
+
+                        if (r.TokenType != JsonTokenType.PropertyName)
+                        {
+                            throw new JsonException("Expected property name.");
+                        }
+
+                        string name = r.GetString()!;
+                        if (!r.Read())
+                        {
+                            throw new JsonException("Unexpected end while reading property value.");
+                        }
+
+                        obj[name] = ReadValue(ref r);
+                    }
+
+                    throw new JsonException("Unexpected end while reading object.");
+
+                case JsonTokenType.StartArray:
+
+                    var list = new List<object>();
+                    while (r.Read())
+                    {
+                        if (r.TokenType == JsonTokenType.EndArray)
+                        {
+                            return list;
+                        }
+
+                        list.Add(ReadValue(ref r));
+                    }
+
+                    throw new JsonException("Unexpected end while reading array.");
+
+                case JsonTokenType.True: return true;
+                case JsonTokenType.False: return false;
+                case JsonTokenType.Null: return null;
+
+                case JsonTokenType.Number:
+
+                    if (r.TryGetInt32(out int i))
+                    {
+                        return i;
+                    }
+
+                    if (r.TryGetInt64(out long l))
+                    {
+                        return l;
+                    }
+
+                    if (r.TryGetDouble(out double d))
+                    {
+                        return d;
+                    }
+
+                    return r.GetDecimal();
+
+                case JsonTokenType.String:
+
+                    string s = r.GetString()!;
+
+                    if (DateTimeOffset.TryParse(s, out var dto))
+                    {
+                        return dto;
+                    }
+
+                    if (DateTime.TryParse(s, out var dt))
+                    {
+                        return dt;
+                    }
+
+                    if (TimeSpan.TryParse(s, out var ts))
+                    {
+                        return ts;
+                    }
+
+                    if (Guid.TryParse(s, out var g))
+                    {
+                        return g;
+                    }
+
+                    return s;
+
+                default:
+                    throw new JsonException($"Unsupported token {r.TokenType}");
+            }
+        }
+
+        public override void Write(Utf8JsonWriter writer, object value, JsonSerializerOptions options)
+        {
+            if (value is null)
+            {
+                writer.WriteNullValue();
+                return;
+            }
+
+            writer.WriteStartObject();
+            writer.WriteEndObject();
+        }
+    }
+}