Address review feedback

src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonIgnoreCondition.cs

@@ -5,21 +5,23 @@
 namespace System.Text.Json.Serialization
 {
     /// <summary>
-    /// When specified on <see cref="JsonSerializerOptions.DefaultIgnoreCondition"/>, controls whether properties with default values are ignored during serialization.
-    /// When specified on <see cref="JsonIgnoreAttribute.Condition"/>, controls whether a property is ignored during serialization and deserialization.
+    /// When specified on <see cref="JsonSerializerOptions.DefaultIgnoreCondition"/>,
+    /// <see cref="WhenWritingDefault"/> specifies that properties with default values are ignored during serialization.
+    /// When specified on <see cref="JsonIgnoreAttribute.Condition"/>, controls whether
+    /// a property is ignored during serialization and deserialization.
     /// </summary>
     public enum JsonIgnoreCondition
     {
         /// <summary>
-        /// Property will always be serialized and deserialized.
+        /// Property is never ignored during serialization or deserialization.
         /// </summary>
         Never = 0,
         /// <summary>
-        /// Property will never be serialized or deserialized.
+        /// Property is always ignored during serialization and deserialization.
         /// </summary>
         Always = 1,
         /// <summary>
-        /// Property will not be serialized if it is the default value.
+        /// If the value is the default, the property is ignored during serialization.
         /// </summary>
         WhenWritingDefault = 2,
     }

src/libraries/System.Text.Json/tests/Serialization/CustomConverterTests/CustomConverterTests.HandleNull.cs

@@ -507,5 +507,40 @@ public override void Write(Utf8JsonWriter writer, object value, JsonSerializerOp
 
             public override bool HandleNull => true;
         }
+
+        [Fact]
+        public static void SetterCalledWhenConverterReturnsNull()
+        {
+            var options = new JsonSerializerOptions
+            {
+                IgnoreNullValues = true,
+                Converters = { new UriToNullConverter() }
+            };
+
+            // Baseline - null values ignored, converter is not called.
+            string json = @"{""MyUri"":null}";
+
+            ClassWithInitializedUri obj = JsonSerializer.Deserialize<ClassWithInitializedUri>(json, options);
+            Assert.Equal(new Uri("https://microsoft.com"), obj.MyUri);
+
+            // Baseline - setter is called if payload is not null and converter returns null.
+            json = @"{""MyUri"":""https://default""}";
+            obj = JsonSerializer.Deserialize<ClassWithInitializedUri>(json, options);
+            Assert.Null(obj.MyUri);
+        }
+
+        private class ClassWithInitializedUri
+        {
+            public Uri MyUri { get; set; } = new Uri("https://microsoft.com");
+        }
+
+        public class UriToNullConverter : JsonConverter<Uri>
+        {
+            public override Uri Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) => null;
+
+            public override void Write(Utf8JsonWriter writer, Uri value, JsonSerializerOptions options) => throw new NotImplementedException();
+
+            public override bool HandleNull => true;
+        }
     }
 }