Add test to show that RegisterType can be used instead of ctor.

Author: JKamsker

LiteDB.Tests/Issues/Issue2298_Tests.cs

@@ -0,0 +1,67 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.Json;
+using System.Threading.Tasks;
+
+using Xunit;
+
+namespace LiteDB.Tests.Issues;
+
+public class Issue2298_Tests
+{
+    public struct Mass
+    {
+        public enum Units
+        { Pound, Kilogram }
+
+        public Mass(double value, Units unit)
+        { Value = value; Unit = unit; }
+
+        public double Value { get; init; }
+        public Units Unit { get; init; }
+    }
+
+    public class QuantityRange<T>
+    {
+        public QuantityRange(double min, double max, Enum unit)
+        { Min = min; Max = max; Unit = unit; }
+
+        public double Min { get; init; }
+        public double Max { get; init; }
+        public Enum Unit { get; init; }
+    }
+
+    public static QuantityRange<Mass> MassRangeBuilder(BsonDocument document)
+    {
+        var doc = JsonDocument.Parse(document.ToString()).RootElement;
+        var min = doc.GetProperty(nameof(QuantityRange<Mass>.Min)).GetDouble();
+        var max = doc.GetProperty(nameof(QuantityRange<Mass>.Max)).GetDouble();
+        var unit = Enum.Parse<Mass.Units>(doc.GetProperty(nameof(QuantityRange<Mass>.Unit)).GetString());
+
+        var restored = new QuantityRange<Mass>(min, max, unit);
+        return restored;
+    }
+
+    [Fact]
+    public void We_Dont_Need_Ctor()
+    {
+        BsonMapper.Global.RegisterType<QuantityRange<Mass>>(
+            serialize: (range) => new BsonDocument
+            {
+                { nameof(QuantityRange<Mass>.Min), range.Min },
+                { nameof(QuantityRange<Mass>.Max), range.Max },
+                { nameof(QuantityRange<Mass>.Unit), range.Unit.ToString() }
+            },
+            deserialize: (document) => MassRangeBuilder(document as BsonDocument)
+        );
+
+        var range = new QuantityRange<Mass>(100, 500, Mass.Units.Pound);
+        var filename = "Demo.DB";
+        var DB = new LiteDatabase(filename);
+        var collection = DB.GetCollection<QuantityRange<Mass>>("DEMO");
+        collection.Insert(range);
+        var restored = collection.FindAll().First();
+    }
+}