Fixed SystemTextJson indexed properties handling. (#1701)

* Fixed SystemTextJson indexed properties handling.

* Fixed CA1859 error.

* Revert "Fixed CA1859 error."

This reverts commit d7297d5.

* Disabled check for CA1859.

---------

Co-authored-by: ViktoriiaZheliezniak <viktoriia.zheliezniak@vinci-energies.net>

src/NJsonSchema.Tests/Generation/SystemTextJson/SystemTextJsonExtensionDataGenerationTests.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Text.Json;
 using System.Text.Json.Serialization;
 using NJsonSchema.Generation;
@@ -24,6 +25,56 @@ public class ClassWithJsonElementExtensionData
             public IDictionary<string, JsonElement> ExtensionData { get; set; }
         }
 
+        public class ClassWithIndexedProperty
+        {
+            public double X { get; set; }
+            public double Y { get; set; }
+
+            public double this[int indexer]
+            {
+                get
+                {
+                    switch (indexer)
+                    {
+                        case 0: return X;
+                        case 1: return Y;
+                        default: throw new ArgumentOutOfRangeException(nameof(indexer));
+                    }
+                }
+                set
+                {
+                    switch (indexer)
+                    {
+                        case 0: X = value; break;
+                        case 1: Y = value; break;
+                        default: throw new ArgumentOutOfRangeException(nameof(indexer));
+                    }
+                }
+            }
+
+            public double this[string indexer]
+            {
+                get
+                {
+                    switch (indexer)
+                    {
+                        case "X": return X;
+                        case "Y": return Y;
+                        default: throw new ArgumentOutOfRangeException(nameof(indexer));
+                    }
+                }
+                set
+                {
+                    switch (indexer)
+                    {
+                        case "X": X = value; break;
+                        case "Y": Y = value; break;
+                        default: throw new ArgumentOutOfRangeException(nameof(indexer));
+                    }
+                }
+            }
+        }
+
         [Fact]
         public void SystemTextJson_When_class_has_object_Dictionary_with_JsonExtensionDataAttribute_on_property_then_AdditionalProperties_schema_is_set()
         {
@@ -53,5 +104,19 @@ public void SystemTextJson_When_class_has_JsonElement_Dictionary_with_JsonExtens
             Assert.True(schema.AllowAdditionalProperties);
             Assert.True(schema.AdditionalPropertiesSchema.ActualSchema.IsAnyType);
         }
+
+        [Fact]
+        public void SystemTextJson_When_class_has_Indexed_properties_then_Generates_schema_without_them()
+        {
+            // Act
+            var schema = JsonSchemaGenerator.FromType<ClassWithIndexedProperty>(new SystemTextJsonSchemaGeneratorSettings
+            {
+                SchemaType = SchemaType.JsonSchema
+            });
+
+            // Assert
+            Assert.Equal(2, schema.ActualProperties.Count);
+            Assert.All(schema.ActualProperties, property => Assert.False(string.Equals(property.Key, "Item", StringComparison.InvariantCultureIgnoreCase)));
+        }
     }
 }

src/NJsonSchema/Generation/JsonSchemaGenerator.cs

@@ -1089,6 +1089,7 @@ private void GenerateInheritanceDiscriminator(Type type, JsonSchema schema, Json
             }
         }
 
+#pragma warning disable CA1859
         private object? TryGetInheritanceDiscriminatorConverter(Type type)
         {
             var typeAttributes = type.GetTypeInfo().GetCustomAttributes(false).OfType<Attribute>();
@@ -1099,8 +1100,8 @@ private void GenerateInheritanceDiscriminator(Type type, JsonSchema schema, Json
             {
                 var converterType = (Type)jsonConverterAttribute.ConverterType;
                 if (converterType != null && (
-                    converterType.IsAssignableToTypeName("JsonInheritanceConverter", TypeNameStyle.Name) || // Newtonsoft's converter
-                    converterType.IsAssignableToTypeName("JsonInheritanceConverter`1", TypeNameStyle.Name) // System.Text.Json's converter
+                        converterType.IsAssignableToTypeName("JsonInheritanceConverter", TypeNameStyle.Name) || // Newtonsoft's converter
+                        converterType.IsAssignableToTypeName("JsonInheritanceConverter`1", TypeNameStyle.Name) // System.Text.Json's converter
                     ))
                 {
                     return ObjectExtensions.HasProperty(jsonConverterAttribute, "ConverterParameters") &&
@@ -1125,6 +1126,8 @@ private void GenerateInheritanceDiscriminator(Type type, JsonSchema schema, Json
 
             return null;
         }
+#pragma warning restore CA1859
+
 
         private sealed class SystemTextJsonInheritanceWrapper
         {

src/NJsonSchema/Generation/SystemTextJsonReflectionService.cs

@@ -45,6 +45,12 @@ public override void GenerateProperties(JsonSchema schema, ContextualType contex
                     continue;
                 }
 
+                if (accessorInfo.MemberInfo is PropertyInfo propInfo &&
+                    propInfo.GetIndexParameters().Length > 0)
+                {
+                    continue;
+                }
+
                 var propertyIgnored = false;
                 var jsonIgnoreAttribute = accessorInfo
                     .GetAttributes(true)