Change:
The apimachinery roundtripping test does not ensure that deep copies work. We need to provide a deep copy test that makes sure we don't end up with shallow copies.
I looked into gofuzz some days ago and noticed that it does not support value-only fuzzing that preserves object structure (= does not change pointer values). So we need something clever, maybe reflection based here. Any other idea?

Discussion:
t.Errorf("3: %v: diff: %vnCodec: %#v", name, diff.ObjectReflectDiff(object, obj3), codec) return } <ins> // do structure-preserving fuzzing of the deep-copied object. If it shares anything with the original, // the deep-copy was actually only a shallow copy. Then original and obj3 will be different after fuzzing. // NOTE: we use the encoding+decoding here as an alternative, guaranteed deep-copy to compare against. ValueFuzz(object) if !apiequality.Semantic.DeepEqual(original, obj3) { t.Errorf("0: %v: fuzzing a copy altered the original, diff: %v", name, diff.ObjectReflectDiff(original, object)) return } </ins> } // dataAsString returns the given byte array as a string; handles detecting

<ins> /* Copyright 2017 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 testing import ( "reflect" ) // ValueFuzz recursively changes all basic type values in an object. Any kind of references will not // be touch, i.e. the addresses of slices, maps, pointers will stay unchanged. func ValueFuzz(obj interface{}) { valueFuzz(reflect.ValueOf(obj)) } func valueFuzz(obj reflect.Value) { switch obj.Kind() { case reflect.Array: for i := 0; i < obj.Len(); i++ { valueFuzz(obj.Index(i)) } case reflect.Slice: if obj.IsNil() { // TODO: set non-nil value } else { for i := 0; i < obj.Len(); i++ { valueFuzz(obj.Index(i)) } } case reflect.Interface, reflect.Ptr: if obj.IsNil() { // TODO: set non-nil value } else { valueFuzz(obj.Elem()) } case reflect.Struct: for i, n := 0, obj.NumField(); i < n; i++ { valueFuzz(obj.Field(i)) } case reflect.Map: if obj.IsNil() { // TODO: set non-nil value } else { for _, k := range obj.MapKeys() { // map values are not addressable. We need a copy. v := obj.MapIndex(k) copy := reflect.New(v.Type()) copy.Elem().Set(v) valueFuzz(copy.Elem()) obj.SetMapIndex(k, copy.Elem()) } // TODO: set some new value } case reflect.Func: // ignore, we don't have function types in our API default: if !obj.CanSet() { return } switch obj.Kind() { case reflect.String: obj.SetString(obj.String() + "x") case reflect.Bool: obj.SetBool(!obj.Bool()) case reflect.Float32, reflect.Float64: obj.SetFloat(obj.Float()*2.0 + 1.0) case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int: obj.SetInt(obj.Int() + 1) case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uint: obj.SetUint(obj.Uint() + 1) default: } } } </ins>

<ins> /* Copyright 2017 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 testing import "testing" func TestValueFuzz(t *testing.T) { type ( Y struct { I int B bool F float32 U uint } X struct { Ptr *X Y Y Map map[string]int Slice []int } ) x := X{ Ptr: &X{}, Map: map[string]int{"foo": 42}, Slice: []int{1,2,3}, } p := x.Ptr m := x.Map s := x.Slice ValueFuzz(x) if x.Ptr.Y.I == 0 { t.Errorf("x.Ptr.Y.I should have changed") } if x.Map["foo"] == 42 { t.Errorf("x.Map[foo] should have changed") } if x.Slice[0] == 1 { t.Errorf("x.Slice[0] should have changed") } if x.Ptr != p { t.Errorf("x.Ptr changed") } m["foo"] = 7 if x.Map["foo"] != m["foo"] { t.Errorf("x.Map changed") } s[0] = 7 if x.Slice[0] != s[0] { t.Errorf("x.Slice changed") } } </ins>

"k8s.io/apimachinery/pkg/api/testing/codec.go", "k8s.io/apimachinery/pkg/api/testing/fuzzer.go", "k8s.io/apimachinery/pkg/api/testing/roundtrip.go", <ins> "k8s.io/apimachinery/pkg/api/testing/valuefuzz.go", </ins> ], tags = ["automanaged"], deps = [

tags = ["automanaged"], deps = ["//vendor:k8s.io/apimachinery/pkg/api/testing"], ) <ins> go_test( name = "k8s.io/apimachinery/pkg/api/testing_test", srcs = ["k8s.io/apimachinery/pkg/api/testing/valuefuzz_test.go"], library = ":k8s.io/apimachinery/pkg/api/testing", tags = ["automanaged"], ) </ins>