pkg/api/testing: add deepcopy smoke test to roundtrip test

staging/src/k8s.io/apimachinery/pkg/api/testing/roundtrip.go

@@ -272,6 +272,15 @@ func roundTrip(t *testing.T, scheme *runtime.Scheme, codec runtime.Codec, object
 		t.Errorf("3: %v: diff: %v\nCodec: %#v", name, diff.ObjectReflectDiff(object, obj3), codec)
 		return
 	}
+
+	// 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
+	}
 }
 
 // dataAsString returns the given byte array as a string; handles detecting

staging/src/k8s.io/apimachinery/pkg/api/testing/valuefuzz.go

@@ -0,0 +1,86 @@
+/*
+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:
+		}
+	}
+}

staging/src/k8s.io/apimachinery/pkg/api/testing/valuefuzz_test.go

@@ -0,0 +1,73 @@
+/*
+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")
+	}
+}

vendor/BUILD

@@ -13851,6 +13851,7 @@ go_library(
         "k8s.io/apimachinery/pkg/api/testing/codec.go",
         "k8s.io/apimachinery/pkg/api/testing/fuzzer.go",
         "k8s.io/apimachinery/pkg/api/testing/roundtrip.go",
+        "k8s.io/apimachinery/pkg/api/testing/valuefuzz.go",
     ],
     tags = ["automanaged"],
     deps = [
@@ -16897,3 +16898,10 @@ go_test(
     tags = ["automanaged"],
     deps = ["//vendor:k8s.io/apimachinery/pkg/api/testing"],
 )
+
+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"],
+)