Ignore From when serializing a JsonPatchDocument for add, remove, rep…

src/Features/JsonPatch.SystemTextJson/src/Operations/OperationBase.cs

@@ -43,8 +43,10 @@ public string op
         }
     }
 
-    [JsonPropertyName(nameof(from))]
-    public string from { get; set; }
+#nullable enable
+    [JsonPropertyName(nameof(from)), JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+    public string? from { get; set; }
+#nullable restore
 
     public OperationBase()
     {
@@ -59,10 +61,4 @@ public OperationBase(string op, string path, string from)
         this.path = path;
         this.from = from;
     }
-
-    public bool ShouldSerializeFrom()
-    {
-        return (OperationType == OperationType.Move
-            || OperationType == OperationType.Copy);
-    }
 }

src/Features/JsonPatch.SystemTextJson/src/PublicAPI.Shipped.txt

@@ -74,7 +74,6 @@
 ~Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.Operation<TModel>.Operation(string op, string path, string from, object value) -> void
 ~Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.Operation<TModel>.Operation(string op, string path, string from) -> void
 ~Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.from.get -> string
-~Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.from.set -> void
 ~Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.op.get -> string
 ~Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.op.set -> void
 ~Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.OperationBase(string op, string path, string from) -> void
@@ -95,7 +94,6 @@ Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.Operation<TModel>.Opera
 Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase
 Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.OperationBase() -> void
 Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.OperationType.get -> Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationType
-Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.ShouldSerializeFrom() -> bool
 Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationType
 Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationType.Add = 0 -> Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationType
 Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationType.Copy = 4 -> Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationType

src/Features/JsonPatch.SystemTextJson/src/PublicAPI.Unshipped.txt

@@ -1 +1,4 @@
 #nullable enable
+
+Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.from.get -> string?
+Microsoft.AspNetCore.JsonPatch.SystemTextJson.Operations.OperationBase.from.set -> void

src/Features/JsonPatch.SystemTextJson/test/JsonPatchDocumentTest.cs

@@ -255,4 +255,26 @@
 
         return JsonSerializer.Serialize<JsonPatchDocument<SimpleObject>>(document, jsonSerializerOptions);
     }
+
+     [Fact]
+    public void Serialization_ShouldExcludeFrom_WhenNullAndNotMoveOrCopy()
+    {
+        // Arrange
+        JsonPatchDocument patchDocument = new();
+        patchDocument.Add("/a/b/c", "foo");
+        patchDocument.Remove("/x/y/z");
+        patchDocument.Replace("/d/e", "bar");
+        patchDocument.Test("/f/e", "t1");
+
+        var json = JsonSerializer.Serialize(patchDocument);
+
+        // Assert
+        var expectedJson = """
+        [{"value":"foo","path":"/a/b/c","op":"add"},{"value":null,"path":"/x/y/z","op":"remove"},
+        { "value":"bar","path":"/d/e","op":"replace"},{ "value":"t1","path":"/f/e","op":"test"}]
+        """;
+
+        // Act
+        Assert.True(JsonNode.DeepEquals(JsonNode.Parse(expectedJson), JsonNode.Parse(json)));
+    }
 }