Respect PropertyNameCaseInsensitive setting

SystemTextJsonPatch.Tests/IntegrationTests/SimpleObjectIntegrationTest.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Dynamic;
+using System.Text.Json;
 using SystemTextJsonPatch.Exceptions;
+using SystemTextJsonPatch.Operations;
 using Xunit;
 
 namespace SystemTextJsonPatch.IntegrationTests;
@@ -164,6 +166,54 @@ public void RegressionAspNetCore3634()
 		Assert.Equal("For operation 'move', the target location specified by path '/Object/goodbye' was not found.", ex.Message);
 	}
 
+	[Fact]
+	public void ShouldFollowCaseInsensitiveSettingOfSystemTextJsonOptions()
+	{
+		var options = new JsonSerializerOptions()
+		{
+			PropertyNameCaseInsensitive = true
+		};
+
+		// Arrange
+		var targetObject = new SimpleObject()
+		{
+			StringProperty = "old",
+		};
+
+		var patchDocument = new JsonPatchDocument<SimpleObject>();
+		patchDocument.Operations.Add(new Operation<SimpleObject>("replace", "/stringproperty", null, "test"));
+		patchDocument.Options = options;
+
+		// Act
+		patchDocument.ApplyTo(targetObject);
+
+		// Assert
+		Assert.Equal("test", targetObject.StringProperty);
+	}
+
+	[Fact]
+	public void FailsWhenPropertyCouldNotBeFoundBecauseOfCasing()
+	{
+		var options = new JsonSerializerOptions()
+		{
+			PropertyNameCaseInsensitive = false
+		};
+
+		// Arrange
+		var targetObject = new SimpleObject()
+		{
+			AnotherStringProperty = "old",
+		};
+
+		var patchDocument = new JsonPatchDocument<SimpleObject>();
+		patchDocument.Operations.Add(new Operation<SimpleObject>("replace", "/anotherstringproperty", null, "test"));
+		patchDocument.Options = options;
+
+		// Act
+		var excpetion = Assert.Throws<JsonPatchException>(() => patchDocument.ApplyTo(targetObject));
+		Assert.Equal("The target location specified by path segment 'anotherstringproperty' was not found.", excpetion.Message);
+	}
+
 	private class RegressionAspNetCore3634Object
 	{
 		public dynamic Object { get; set; }

SystemTextJsonPatch.Tests/JsonPatchDocumentJsonObjectTest.cs

@@ -327,4 +327,36 @@ public void ApplyToModelReplaceNull()
 		// Assert
 		Assert.Null(model.CustomData["Email"]);
 	}
+
+	[Fact]
+	public void ApplyToModelReplaceWithIgnoringCasing()
+	{
+		// Arrange
+		var model = new ObjectWithJsonNode { CustomData = JsonSerializer.SerializeToNode(new { Email = "[email protected]", Name = "Bar" }) };
+		var patch = new JsonPatchDocument<ObjectWithJsonNode>();
+		patch.Options = new JsonSerializerOptions() { PropertyNameCaseInsensitive = true };
+
+		patch.Operations.Add(new Operation<ObjectWithJsonNode>("replace", "/customdata/email", null, "[email protected]"));
+
+		// Act
+		patch.ApplyTo(model);
+
+		// Assert
+		Assert.Equal("[email protected]", model.CustomData["Email"].GetValue<string>());
+	}
+
+
+	[Fact]
+	public void ApplyToModelReplaceWithInvalidCasing()
+	{
+		// Arrange
+		var model = new ObjectWithJsonNode { CustomData = JsonSerializer.SerializeToNode(new { Email = "[email protected]", Name = "Bar" }) };
+		var patch = new JsonPatchDocument<ObjectWithJsonNode>();
+
+		patch.Operations.Add(new Operation<ObjectWithJsonNode>("replace", "/CustomData/email", null, "[email protected]"));
+
+		// Assert
+		var exception = Assert.Throws<JsonPatchException>(() => patch.ApplyTo(model));
+		Assert.Equal("The target location specified by path segment 'email' was not found.", exception.Message);
+	}
 }

SystemTextJsonPatch/Internal/JSonObjectAdapter.cs

@@ -10,7 +10,9 @@ public bool TryAdd(object target, string segment, JsonSerializerOptions options,
 	{
 		var obj = (JsonObject)target;
 
-		obj[segment] = value != null ? JsonSerializer.SerializeToNode(value, options) : null;
+		var propertyName = FindPropertyName(obj, segment, options);
+
+		obj[propertyName] = value != null ? JsonSerializer.SerializeToNode(value, options) : null;
 
 		errorMessage = null;
 		return true;
@@ -20,7 +22,9 @@ public bool TryGet(object target, string segment, JsonSerializerOptions options,
 	{
 		var obj = (JsonObject)target;
 
-		if (!obj.TryGetPropertyValue(segment, out var valueAsToken))
+		var propertyName = FindPropertyName(obj, segment, options);
+
+		if (!obj.TryGetPropertyValue(propertyName, out var valueAsToken))
 		{
 			value = null;
 			errorMessage = Resources.FormatTargetLocationAtPathSegmentNotFound(segment);
@@ -36,7 +40,9 @@ public bool TryRemove(object target, string segment, JsonSerializerOptions optio
 	{
 		var obj = (JsonObject)target;
 
-		if (!obj.Remove(segment))
+		var propertyName = FindPropertyName(obj, segment, options);
+
+		if (!obj.Remove(propertyName))
 		{
 			errorMessage = Resources.FormatTargetLocationAtPathSegmentNotFound(segment);
 			return false;
@@ -50,13 +56,15 @@ public bool TryReplace(object target, string segment, JsonSerializerOptions opti
 	{
 		var obj = (JsonObject)target;
 
-		if (obj[segment] == null)
+		var propertyName = FindPropertyName(obj, segment, options);
+
+		if (obj[propertyName] == null)
 		{
 			errorMessage = Resources.FormatTargetLocationAtPathSegmentNotFound(segment);
 			return false;
 		}
 
-		obj[segment] = value != null ? JsonSerializer.SerializeToNode(value, options) : null;
+		obj[propertyName] = value != null ? JsonSerializer.SerializeToNode(value, options) : null;
 
 		errorMessage = null;
 		return true;
@@ -66,7 +74,9 @@ public bool TryTest(object target, string segment, JsonSerializerOptions options
 	{
 		var obj = (JsonObject)target;
 
-		if (!obj.TryGetPropertyValue(segment, out var currentValue))
+		var propertyName = FindPropertyName(obj, segment, options);
+
+		if (!obj.TryGetPropertyValue(propertyName, out var currentValue))
 		{
 			errorMessage = Resources.FormatTargetLocationAtPathSegmentNotFound(segment);
 			return false;
@@ -95,7 +105,9 @@ public bool TryTraverse(object target, string segment, JsonSerializerOptions opt
 	{
 		var obj = (JsonObject)target;
 
-		if (!obj.TryGetPropertyValue(segment, out JsonNode? nextTargetToken))
+		var propertyName = FindPropertyName(obj, segment, options);
+
+		if (!obj.TryGetPropertyValue(propertyName, out JsonNode? nextTargetToken))
 		{
 			nextTarget = null;
 			errorMessage = null;
@@ -106,4 +118,21 @@ public bool TryTraverse(object target, string segment, JsonSerializerOptions opt
 		errorMessage = null;
 		return true;
 	}
+
+	private static string FindPropertyName(JsonObject? obj, string segment, JsonSerializerOptions options)
+	{
+		if (!options.PropertyNameCaseInsensitive || obj == null)
+			return segment;
+
+		if (obj.ContainsKey(segment))
+			return segment;
+
+		foreach (var node in obj)
+		{
+			if (string.Equals(node.Key, segment, StringComparison.OrdinalIgnoreCase))
+				return node.Key;
+		}
+
+		return segment;
+	}
 }

SystemTextJsonPatch/Internal/PocoAdapter.cs

@@ -224,7 +224,6 @@ private static bool TryGetJsonProperty(object target, string segment, JsonSerial
 			return new JsonNodeProxy(jsonElement, propertyName);
 		}
 
-
-		return PropertyProxyCache.GetPropertyProxy(target.GetType(), propertyName, options.PropertyNamingPolicy);
+		return PropertyProxyCache.GetPropertyProxy(target.GetType(), propertyName, options.PropertyNamingPolicy, options.PropertyNameCaseInsensitive);
 	}
 }

SystemTextJsonPatch/Internal/PropertyProxyCache.cs

@@ -3,7 +3,6 @@
 using System.Reflection;
 using System.Text.Json;
 using System.Text.Json.Serialization;
-using System.Xml.Linq;
 using SystemTextJsonPatch.Exceptions;
 using SystemTextJsonPatch.Internal.Proxies;
 
@@ -15,7 +14,7 @@ internal static class PropertyProxyCache
 		// Naming policy has to be part of the key because it can change the target property
 		private static readonly ConcurrentDictionary<(Type, string, JsonNamingPolicy?), PropertyProxy?> CachedPropertyProxies = new();
 
-		internal static PropertyProxy? GetPropertyProxy(Type type, string propName, JsonNamingPolicy? namingPolicy)
+		internal static PropertyProxy? GetPropertyProxy(Type type, string propName, JsonNamingPolicy? namingPolicy, bool? propertyNameCaseInsensitive)
 		{
 			var key = (type, propName, namingPolicy);
 
@@ -30,19 +29,21 @@ internal static class PropertyProxyCache
 				CachedTypeProperties[type] = properties;
 			}
 
-			propertyProxy = FindPropertyInfo(properties, propName, namingPolicy);
+			propertyProxy = FindPropertyInfo(properties, propName, namingPolicy, propertyNameCaseInsensitive);
 			CachedPropertyProxies[key] = propertyProxy;
 
 			return propertyProxy;
 		}
 
-		private static PropertyProxy? FindPropertyInfo(PropertyInfo[] properties, string propName, JsonNamingPolicy? namingPolicy)
+		private static PropertyProxy? FindPropertyInfo(PropertyInfo[] properties, string propName, JsonNamingPolicy? namingPolicy, bool? propertyNameCaseInsensitive)
 		{
+			var comparison = propertyNameCaseInsensitive == true ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal;
+
 			// First check through all properties if property name matches JsonPropertyNameAttribute
 			foreach (var propertyInfo in properties)
 			{
 				var jsonPropertyNameAttr = propertyInfo.GetCustomAttribute<JsonPropertyNameAttribute>();
-				if (jsonPropertyNameAttr != null && string.Equals(jsonPropertyNameAttr.Name, propName, StringComparison.Ordinal))
+				if (jsonPropertyNameAttr != null && string.Equals(jsonPropertyNameAttr.Name, propName, comparison))
 				{
 					EnsureAccessToProperty(propertyInfo);
 					return new PropertyProxy(propertyInfo);
@@ -54,7 +55,7 @@ internal static class PropertyProxyCache
 			{
 				var propertyName = namingPolicy != null ? namingPolicy.ConvertName(propertyInfo.Name) : propertyInfo.Name;
 
-				if (string.Equals(propertyName, propName, StringComparison.Ordinal))
+				if (string.Equals(propertyName, propName, comparison))
 				{
 					EnsureAccessToProperty(propertyInfo);
 					return new PropertyProxy(propertyInfo);