diff --git a/util/pkg/reflectutils/walk.go b/util/pkg/reflectutils/walk.go index 77f5a1c66b..9fd392d8ae 100644 --- a/util/pkg/reflectutils/walk.go +++ b/util/pkg/reflectutils/walk.go @@ -44,6 +44,7 @@ func IsMethodNotFound(err error) bool { // JSONMergeStruct merges src into dest // It uses a JSON marshal & unmarshal, so only fields that are JSON-visible will be copied +// If both source and destination has a value for a field, source takes presedence func JSONMergeStruct(dest, src interface{}) { // Not the most efficient approach, but simple & relatively well defined j, err := json.Marshal(src) diff --git a/util/pkg/reflectutils/walk_test.go b/util/pkg/reflectutils/walk_test.go new file mode 100644 index 0000000000..d2abb27296 --- /dev/null +++ b/util/pkg/reflectutils/walk_test.go @@ -0,0 +1,40 @@ +/* +Copyright 2022 The Kubernetes Authors. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package reflectutils + +import "testing" + +type testStruct struct { + Value string `json:"value,omitempty"` +} + +func Test_Merge(t *testing.T) { + source := testStruct{ + Value: "foo", + } + + destination := testStruct{ + Value: "bar", + } + + JSONMergeStruct(&destination, &source) + + // verify source value overrides destination + if destination.Value != "foo" { + t.Errorf("unexpected value: %s", destination.Value) + } +}