From aa13a7534acc3117e398526384b04cbb9c396c13 Mon Sep 17 00:00:00 2001
From: Captainpast <captainpast@gmx.de>
Date: Wed, 19 Feb 2025 18:01:15 +0100
Subject: [PATCH 1/2] using generic JsonStringEnumConverter for net8.0

---
 src/GeoJSON.Text/Feature/Feature.cs             | 1 -
 src/GeoJSON.Text/Feature/FeatureCollection.cs   | 2 --
 src/GeoJSON.Text/GeoJSONObject.cs               | 1 -
 src/GeoJSON.Text/GeoJSONObjectType.cs           | 6 ++++++
 src/GeoJSON.Text/Geometry/GeometryCollection.cs | 1 -
 src/GeoJSON.Text/Geometry/IGeometryObject.cs    | 1 -
 src/GeoJSON.Text/Geometry/LineString.cs         | 1 -
 src/GeoJSON.Text/Geometry/MultiLineString.cs    | 1 -
 src/GeoJSON.Text/Geometry/MultiPoint.cs         | 1 -
 src/GeoJSON.Text/Geometry/MultiPolygon.cs       | 1 -
 src/GeoJSON.Text/Geometry/Point.cs              | 1 -
 src/GeoJSON.Text/Geometry/Polygon.cs            | 1 -
 12 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/src/GeoJSON.Text/Feature/Feature.cs b/src/GeoJSON.Text/Feature/Feature.cs
index 5568519..ba4d2bd 100644
--- a/src/GeoJSON.Text/Feature/Feature.cs
+++ b/src/GeoJSON.Text/Feature/Feature.cs
@@ -49,7 +49,6 @@ public Feature(IGeometryObject geometry, TProps properties, string id = null)
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.Feature;
 
         [JsonPropertyName( "id")]
diff --git a/src/GeoJSON.Text/Feature/FeatureCollection.cs b/src/GeoJSON.Text/Feature/FeatureCollection.cs
index 8caeefc..2e1243e 100644
--- a/src/GeoJSON.Text/Feature/FeatureCollection.cs
+++ b/src/GeoJSON.Text/Feature/FeatureCollection.cs
@@ -37,7 +37,6 @@ public FeatureCollection(List<Feature> features)
 
     [JsonPropertyName("type")]
     [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-    [JsonConverter(typeof(JsonStringEnumConverter))]
     public override GeoJSONObjectType Type => GeoJSONObjectType.FeatureCollection;
 
     /// <summary>
@@ -156,7 +155,6 @@ public FeatureCollection(List<Feature<IGeometryObject, TProps>> features)
 
     [JsonPropertyName("type")]
     [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-    [JsonConverter(typeof(JsonStringEnumConverter))]
     public override GeoJSONObjectType Type => GeoJSONObjectType.FeatureCollection;
 
     /// <summary>
diff --git a/src/GeoJSON.Text/GeoJSONObject.cs b/src/GeoJSON.Text/GeoJSONObject.cs
index 2e69d81..8adf906 100644
--- a/src/GeoJSON.Text/GeoJSONObject.cs
+++ b/src/GeoJSON.Text/GeoJSONObject.cs
@@ -55,7 +55,6 @@ public abstract class GeoJSONObject : IGeoJSONObject, IEqualityComparer<GeoJSONO
         /// </summary>
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public abstract GeoJSONObjectType Type { get; }
 
 
diff --git a/src/GeoJSON.Text/GeoJSONObjectType.cs b/src/GeoJSON.Text/GeoJSONObjectType.cs
index ed3ae0e..b8d8582 100644
--- a/src/GeoJSON.Text/GeoJSONObjectType.cs
+++ b/src/GeoJSON.Text/GeoJSONObjectType.cs
@@ -1,12 +1,18 @@
 // Copyright © Joerg Battermann 2014, Matt Hunt 2017
 
 using System.Runtime.Serialization;
+using System.Text.Json.Serialization;
 
 namespace GeoJSON.Text
 {
     /// <summary>
     /// Defines the GeoJSON Objects types.
     /// </summary>
+#if NET8_0_OR_GREATER
+    [JsonConverter(typeof(JsonStringEnumConverter<GeoJSONObjectType>))]
+#else
+    [JsonConverter(typeof(JsonStringEnumConverter))]
+#endif
     public enum GeoJSONObjectType
     {
         /// <summary>
diff --git a/src/GeoJSON.Text/Geometry/GeometryCollection.cs b/src/GeoJSON.Text/Geometry/GeometryCollection.cs
index ee32cbb..3381eff 100644
--- a/src/GeoJSON.Text/Geometry/GeometryCollection.cs
+++ b/src/GeoJSON.Text/Geometry/GeometryCollection.cs
@@ -36,7 +36,6 @@ public GeometryCollection(IEnumerable<IGeometryObject> geometries)
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.GeometryCollection;
 
         /// <summary>
diff --git a/src/GeoJSON.Text/Geometry/IGeometryObject.cs b/src/GeoJSON.Text/Geometry/IGeometryObject.cs
index 9fe7592..c757537 100644
--- a/src/GeoJSON.Text/Geometry/IGeometryObject.cs
+++ b/src/GeoJSON.Text/Geometry/IGeometryObject.cs
@@ -23,7 +23,6 @@ public interface IGeometryObject
         /// The type of the object.
         /// </value>
         [JsonPropertyName("type")]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         GeoJSONObjectType Type { get; }
     }
 }
diff --git a/src/GeoJSON.Text/Geometry/LineString.cs b/src/GeoJSON.Text/Geometry/LineString.cs
index 1b17959..797b7ff 100644
--- a/src/GeoJSON.Text/Geometry/LineString.cs
+++ b/src/GeoJSON.Text/Geometry/LineString.cs
@@ -52,7 +52,6 @@ public LineString(IEnumerable<IPosition> coordinates)
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.LineString;
 
         /// <summary>
diff --git a/src/GeoJSON.Text/Geometry/MultiLineString.cs b/src/GeoJSON.Text/Geometry/MultiLineString.cs
index c33f99e..9b349a4 100644
--- a/src/GeoJSON.Text/Geometry/MultiLineString.cs
+++ b/src/GeoJSON.Text/Geometry/MultiLineString.cs
@@ -46,7 +46,6 @@ public MultiLineString(IEnumerable<IEnumerable<IEnumerable<double>>> coordinates
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.MultiLineString;
 
         /// <summary>
diff --git a/src/GeoJSON.Text/Geometry/MultiPoint.cs b/src/GeoJSON.Text/Geometry/MultiPoint.cs
index cb97fe7..307fc04 100644
--- a/src/GeoJSON.Text/Geometry/MultiPoint.cs
+++ b/src/GeoJSON.Text/Geometry/MultiPoint.cs
@@ -40,7 +40,6 @@ public MultiPoint(IEnumerable<IEnumerable<double>> coordinates)
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.MultiPoint;
 
         /// <summary>
diff --git a/src/GeoJSON.Text/Geometry/MultiPolygon.cs b/src/GeoJSON.Text/Geometry/MultiPolygon.cs
index 3c9b261..66342a9 100644
--- a/src/GeoJSON.Text/Geometry/MultiPolygon.cs
+++ b/src/GeoJSON.Text/Geometry/MultiPolygon.cs
@@ -42,7 +42,6 @@ public MultiPolygon(IEnumerable<IEnumerable<IEnumerable<IEnumerable<double>>>> c
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.MultiPolygon;
 
         /// <summary>
diff --git a/src/GeoJSON.Text/Geometry/Point.cs b/src/GeoJSON.Text/Geometry/Point.cs
index 19724a0..7db90f9 100644
--- a/src/GeoJSON.Text/Geometry/Point.cs
+++ b/src/GeoJSON.Text/Geometry/Point.cs
@@ -31,7 +31,6 @@ public Point(IPosition coordinates)
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.Point;
 
         /// <summary>
diff --git a/src/GeoJSON.Text/Geometry/Polygon.cs b/src/GeoJSON.Text/Geometry/Polygon.cs
index 6c78a53..aa55cbc 100644
--- a/src/GeoJSON.Text/Geometry/Polygon.cs
+++ b/src/GeoJSON.Text/Geometry/Polygon.cs
@@ -57,7 +57,6 @@ public Polygon(IEnumerable<IEnumerable<IEnumerable<double>>> coordinates)
 
         [JsonPropertyName("type")]
         [JsonIgnore(Condition = JsonIgnoreCondition.Never)]
-        [JsonConverter(typeof(JsonStringEnumConverter))]
         public override GeoJSONObjectType Type => GeoJSONObjectType.Polygon;
 
         /// <summary>

From a5e6693e9c0e6d5483a4dad35f8860e019bf1684 Mon Sep 17 00:00:00 2001
From: Captainpast <captainpast@gmx.de>
Date: Wed, 19 Feb 2025 18:02:35 +0100
Subject: [PATCH 2/2] Define the type of CrsConverter

---
 src/GeoJSON.Text/Converters/CrsConverter.cs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/GeoJSON.Text/Converters/CrsConverter.cs b/src/GeoJSON.Text/Converters/CrsConverter.cs
index 5fadd87..d4d8674 100644
--- a/src/GeoJSON.Text/Converters/CrsConverter.cs
+++ b/src/GeoJSON.Text/Converters/CrsConverter.cs
@@ -10,7 +10,7 @@ namespace GeoJSON.Text.Converters
     /// <summary>
     /// Converts <see cref="ICRSObject"/> types to and from JSON.
     /// </summary>
-    public class CrsConverter : JsonConverter<object>
+    public class CrsConverter : JsonConverter<ICRSObject>
     {
         public override bool HandleNull => true;
 
@@ -41,7 +41,7 @@ public override bool CanConvert(Type objectType)
         ///     or
         /// CRS must have a "type" property
         /// </exception>
-        public override object Read(
+        public override ICRSObject Read(
             ref Utf8JsonReader reader,
             Type type,
             JsonSerializerOptions options)
@@ -106,7 +106,8 @@ public override object Read(
                 }
             }
 
-            return new NotSupportedException(string.Format("Type {0} unexpected.", crsType));
+            //return new NotSupportedException(string.Format("Type {0} unexpected.", crsType));
+            return null;
         }
 
         /// <summary>
@@ -118,7 +119,7 @@ public override object Read(
         /// <exception cref="System.ArgumentOutOfRangeException"></exception>
         public override void Write(
             Utf8JsonWriter writer,
-            object crsValue,
+            ICRSObject crsValue,
             JsonSerializerOptions options)
         {
             var value = (ICRSObject)crsValue;