Fix ExtractItems to preserve empty maps and lists

typed/remove.go

@@ -58,6 +58,10 @@ func (w *removingWalker) doList(t *schema.List) (errs ValidationErrors) {
 	defer w.allocator.Free(l)
 	// If list is null or empty just return
 	if l == nil || l.Length() == 0 {
+		// For extraction, we just return the value as is (which is nil or empty). For extraction the difference matters.
+		if w.shouldExtract {
+			w.out = w.value.Unstructured()
+		}
 		return nil
 	}
 
@@ -113,6 +117,10 @@ func (w *removingWalker) doMap(t *schema.Map) ValidationErrors {
 	}
 	// If map is null or empty just return
 	if m == nil || m.Empty() {
+		// For extraction, we just return the value as is (which is nil or empty). For extraction the difference matters.
+		if w.shouldExtract {
+			w.out = w.value.Unstructured()
+		}
 		return nil
 	}
 

typed/remove_test.go

@@ -675,6 +675,38 @@ var removeCases = []removeTestCase{{
 		),
 		`{"mapOfMapsRecursive":{"a":{"b":null}}}`,
 		`{"mapOfMapsRecursive": {"a":{"b":{"c":null}}}}`,
+	}, {
+		// empty list
+		`{"listOfLists": []}`,
+		_NS(
+			_P("listOfLists"),
+		),
+		``,
+		`{"listOfLists": []}`,
+	}, {
+		// null list
+		`{"listOfLists": null}`,
+		_NS(
+			_P("listOfLists"),
+		),
+		``,
+		`{"listOfLists": null}`,
+	}, {
+		// empty map
+		`{"mapOfMaps": {}}`,
+		_NS(
+			_P("mapOfMaps"),
+		),
+		``,
+		`{"mapOfMaps": {}}`,
+	}, {
+		// nil map
+		`{"mapOfMaps": null}`,
+		_NS(
+			_P("mapOfMaps"),
+		),
+		``,
+		`{"mapOfMaps": null}`,
 	}},
 }}