Implemented the following WNode methods:

* GetFieldValue
* GetSlice
* GetString
* Map
* SetAnnotations
* SetGvk
* SetLabels
* SetName
* SetNamespace

api/go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/evanphx/json-patch v4.5.0+incompatible
 	github.com/go-openapi/spec v0.19.5
 	github.com/golangci/golangci-lint v1.21.0
+	github.com/google/go-cmp v0.3.0
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510
 	github.com/pkg/errors v0.8.1
 	github.com/stretchr/testify v1.4.0

api/internal/wrappy/factory_test.go

@@ -1,4 +1,4 @@
 // Copyright 2020 The Kubernetes Authors.
 // SPDX-License-Identifier: Apache-2.0
 
-package wrappy_test
+package wrappy

api/internal/wrappy/wnode.go

@@ -4,7 +4,9 @@
 package wrappy
 
 import (
+	"fmt"
 	"log"
+	"strings"
 
 	"sigs.k8s.io/kustomize/api/ifc"
 	"sigs.k8s.io/kustomize/api/resid"
@@ -54,10 +56,41 @@ func (wn *WNode) GetAnnotations() map[string]string {
 
 // GetFieldValue implements ifc.Kunstructured.
 func (wn *WNode) GetFieldValue(path string) (interface{}, error) {
-	// The argument is a json path, e.g. "metadata.name"
+	fields := strings.Split(path, ".")
-	// fields := strings.Split(path, ".")
+	rn, err := wn.node.Pipe(yaml.Lookup(fields...))
-	// return wn.node.Pipe(yaml.Lookup(fields...))
+	if err != nil {
-	panic("TODO(#WNode): GetFieldValue; implement or drop from API")
+		return nil, err
+	}
+	if rn == nil {
+		return nil, NoFieldError{path}
+	}
+	yn := rn.YNode()
+
+	// If this is an alias node, resolve it
+	if yn.Kind == yaml.AliasNode {
+		yn = yn.Alias
+	}
+
+	// Return value as map for DocumentNode and MappingNode kinds
+	if yn.Kind == yaml.DocumentNode || yn.Kind == yaml.MappingNode {
+		var result map[string]interface{}
+		if err := yn.Decode(&result); err != nil {
+			return nil, err
+		}
+		return result, err
+	}
+
+	// Return value as slice for SequenceNode kind
+	if yn.Kind == yaml.SequenceNode {
+		var result []interface{}
+		for _, node := range yn.Content {
+			result = append(result, node.Value)
+		}
+		return result, nil
+	}
+
+	// Return value value directly for all other (ScalarNode) kinds
+	return yn.Value, nil
 }
 
 // GetGvk implements ifc.Kunstructured.
@@ -83,18 +116,37 @@ func (wn *WNode) GetName() string {
 }
 
 // GetSlice implements ifc.Kunstructured.
-func (wn *WNode) GetSlice(string) ([]interface{}, error) {
+func (wn *WNode) GetSlice(path string) ([]interface{}, error) {
-	panic("TODO(#WNode) GetSlice; implement or drop from API")
+	value, err := wn.GetFieldValue(path)
+	if err != nil {
+		return nil, err
+	}
+	if sliceValue, ok := value.([]interface{}); ok {
+		return sliceValue, nil
+	}
+	return nil, fmt.Errorf("node %s is not a slice", path)
 }
 
 // GetSlice implements ifc.Kunstructured.
-func (wn *WNode) GetString(string) (string, error) {
+func (wn *WNode) GetString(path string) (string, error) {
-	panic("TODO(#WNode) GetString; implement or drop from API")
+	value, err := wn.GetFieldValue(path)
+	if err != nil {
+		return "", err
+	}
+	if v, ok := value.(string); ok {
+		return v, nil
+	}
+	return "", fmt.Errorf("node %s is not a string: %v", path, value)
 }
 
 // Map implements ifc.Kunstructured.
 func (wn *WNode) Map() map[string]interface{} {
-	panic("TODO(#WNode) Map; implement or drop from API")
+	var result map[string]interface{}
+	if err := wn.node.YNode().Decode(&result); err != nil {
+		// Log and die since interface doesn't allow error.
+		log.Fatalf("failed to decode ynode: %v", err)
+	}
+	return result
 }
 
 // MarshalJSON implements ifc.Kunstructured.
@@ -113,31 +165,51 @@ func (wn *WNode) MatchesLabelSelector(string) (bool, error) {
 }
 
 // SetAnnotations implements ifc.Kunstructured.
-func (wn *WNode) SetAnnotations(map[string]string) {
+func (wn *WNode) SetAnnotations(annotations map[string]string) {
-	panic("TODO(#WNode) SetAnnotations; implement or drop from API")
+	wn.setField(yaml.NewMapRNode(&annotations), yaml.MetadataField, yaml.AnnotationsField)
 }
 
 // SetGvk implements ifc.Kunstructured.
-func (wn *WNode) SetGvk(resid.Gvk) {
+func (wn *WNode) SetGvk(gvk resid.Gvk) {
-	panic("TODO(#WNode) SetGvk; implement or drop from API")
+	wn.setField(yaml.NewScalarRNode(gvk.Kind), yaml.KindField)
+	wn.setField(yaml.NewScalarRNode(fmt.Sprintf("%s/%s", gvk.Group, gvk.Version)), yaml.APIVersionField)
 }
 
 // SetLabels implements ifc.Kunstructured.
-func (wn *WNode) SetLabels(map[string]string) {
+func (wn *WNode) SetLabels(labels map[string]string) {
-	panic("TODO(#WNode) SetLabels; implement or drop from API")
+	wn.setField(yaml.NewMapRNode(&labels), yaml.MetadataField, yaml.LabelsField)
 }
 
 // SetName implements ifc.Kunstructured.
-func (wn *WNode) SetName(string) {
+func (wn *WNode) SetName(name string) {
-	panic("TODO(#WNode) SetName; implement or drop from API")
+	wn.setField(yaml.NewScalarRNode(name), yaml.MetadataField, yaml.NameField)
 }
 
 // SetNamespace implements ifc.Kunstructured.
-func (wn *WNode) SetNamespace(string) {
+func (wn *WNode) SetNamespace(ns string) {
-	panic("TODO(#WNode) SetNamespace; implement or drop from API")
+	wn.setField(yaml.NewScalarRNode(ns), yaml.MetadataField, yaml.NamespaceField)
+}
+
+func (wn *WNode) setField(value *yaml.RNode, path ...string) {
+	err := wn.node.PipeE(
+		yaml.LookupCreate(yaml.MappingNode, path[0:len(path)-1]...),
+		yaml.SetField(path[len(path)-1], value),
+	)
+	if err != nil {
+		// Log and die since interface doesn't allow error.
+		log.Fatalf("failed to set field %v: %v", path, err)
+	}
 }
 
 // UnmarshalJSON implements ifc.Kunstructured.
 func (wn *WNode) UnmarshalJSON(data []byte) error {
 	return wn.node.UnmarshalJSON(data)
 }
+
+type NoFieldError struct {
+	Field string
+}
+
+func (e NoFieldError) Error() string {
+	return fmt.Sprintf("no field named '%s'", e.Field)
+}

api/internal/wrappy/wnode_test.go

@@ -1,14 +1,16 @@
 // Copyright 2019 The Kubernetes Authors.
 // SPDX-License-Identifier: Apache-2.0
 
-package wrappy_test
+package wrappy
 
 import (
 	"strings"
 	"testing"
 
+	"github.com/google/go-cmp/cmp"
+	"sigs.k8s.io/kustomize/api/resid"
+
 	"gopkg.in/yaml.v3"
-	. "sigs.k8s.io/kustomize/api/internal/wrappy"
 	kyaml "sigs.k8s.io/kustomize/kyaml/yaml"
 )
 
@@ -337,3 +339,215 @@ func TestGettingFields(t *testing.T) {
 		t.Fatalf("unexpected annotations '%v'", actualMap)
 	}
 }
+
+func TestGetFieldValueReturnsMap(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	expected := map[string]interface{}{
+		"fruit":  "apple",
+		"veggie": "carrot",
+	}
+	actual, err := wn.GetFieldValue("metadata.labels")
+	if err != nil {
+		t.Fatalf("error getting field value: %v", err)
+	}
+	if diff := cmp.Diff(expected, actual); diff != "" {
+		t.Fatalf("actual map does not deep equal expected map:\n%v", diff)
+	}
+}
+
+func TestGetFieldValueReturnsSlice(t *testing.T) {
+	bytes, err := yaml.Marshal(makeBigMap())
+	if err != nil {
+		t.Fatalf("unexpected yaml.Marshal err: %v", err)
+	}
+	rNode, err := kyaml.Parse(string(bytes))
+	if err != nil {
+		t.Fatalf("unexpected yaml.Marshal err: %v", err)
+	}
+	wn := FromRNode(rNode)
+	expected := []interface{}{"idx0", "idx1", "idx2", "idx3"}
+	actual, err := wn.GetFieldValue("that")
+	if err != nil {
+		t.Fatalf("error getting slice: %v", err)
+	}
+	if diff := cmp.Diff(expected, actual); diff != "" {
+		t.Fatalf("actual slice does not deep equal expected slice:\n%v", diff)
+	}
+}
+
+func TestGetFieldValueReturnsString(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	actual, err := wn.GetFieldValue("metadata.labels.fruit")
+	if err != nil {
+		t.Fatalf("error getting field value: %v", err)
+	}
+	v, ok := actual.(string)
+	if !ok || v != "apple" {
+		t.Fatalf("unexpected value '%v'", actual)
+	}
+}
+
+func TestGetFieldValueResolvesAlias(t *testing.T) {
+	yamlWithAlias := `
+foo: &a theValue
+bar: *a
+`
+	rNode, err := kyaml.Parse(yamlWithAlias)
+	if err != nil {
+		t.Fatalf("unexpected yaml parse error: %v", err)
+	}
+	wn := FromRNode(rNode)
+	actual, err := wn.GetFieldValue("bar")
+	if err != nil {
+		t.Fatalf("error getting field value: %v", err)
+	}
+	v, ok := actual.(string)
+	if !ok || v != "theValue" {
+		t.Fatalf("unexpected value '%v'", actual)
+	}
+}
+
+func TestGetString(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	expected := "carrot"
+	actual, err := wn.GetString("metadata.labels.veggie")
+	if err != nil {
+		t.Fatalf("error getting string: %v", err)
+	}
+	if expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+}
+
+func TestGetSlice(t *testing.T) {
+	bytes, err := yaml.Marshal(makeBigMap())
+	if err != nil {
+		t.Fatalf("unexpected yaml.Marshal err: %v", err)
+	}
+	rNode, err := kyaml.Parse(string(bytes))
+	if err != nil {
+		t.Fatalf("unexpected yaml.Marshal err: %v", err)
+	}
+	wn := FromRNode(rNode)
+	expected := []interface{}{"idx0", "idx1", "idx2", "idx3"}
+	actual, err := wn.GetSlice("that")
+	if err != nil {
+		t.Fatalf("error getting slice: %v", err)
+	}
+	if diff := cmp.Diff(expected, actual); diff != "" {
+		t.Fatalf("actual slice does not deep equal expected slice:\n%v", diff)
+	}
+}
+
+func TestMap(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentLittleJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+
+	expected := map[string]interface{}{
+		"apiVersion": "apps/v1",
+		"kind":       "Deployment",
+		"metadata": map[string]interface{}{
+			"name":      "homer",
+			"namespace": "simpsons",
+		},
+	}
+
+	actual := wn.Map()
+	if diff := cmp.Diff(expected, actual); diff != "" {
+		t.Fatalf("actual map does not deep equal expected map:\n%v", diff)
+	}
+}
+
+func TestSetName(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	wn.SetName("marge")
+	if expected, actual := "marge", wn.GetName(); expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+}
+
+func TestSetNamespace(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	wn.SetNamespace("flanders")
+	meta, _ := wn.node.GetMeta()
+	if expected, actual := "flanders", meta.Namespace; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+}
+
+func TestSetLabels(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	wn.SetLabels(map[string]string{
+		"label1": "foo",
+		"label2": "bar",
+	})
+	labels := wn.GetLabels()
+	if expected, actual := 2, len(labels); expected != actual {
+		t.Fatalf("expected '%d', got '%d'", expected, actual)
+	}
+	if expected, actual := "foo", labels["label1"]; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	if expected, actual := "bar", labels["label2"]; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+}
+
+func TestGetAnnotations(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	wn.SetAnnotations(map[string]string{
+		"annotation1": "foo",
+		"annotation2": "bar",
+	})
+	annotations := wn.GetAnnotations()
+	if expected, actual := 2, len(annotations); expected != actual {
+		t.Fatalf("expected '%d', got '%d'", expected, actual)
+	}
+	if expected, actual := "foo", annotations["annotation1"]; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	if expected, actual := "bar", annotations["annotation2"]; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+}
+
+func TestSetGvk(t *testing.T) {
+	wn := NewWNode()
+	if err := wn.UnmarshalJSON([]byte(deploymentBiggerJson)); err != nil {
+		t.Fatalf("unexpected unmarshaljson err: %v", err)
+	}
+	wn.SetGvk(resid.GvkFromString("grp_ver_knd"))
+	gvk := wn.GetGvk()
+	if expected, actual := "grp", gvk.Group; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	if expected, actual := "ver", gvk.Version; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+	if expected, actual := "knd", gvk.Kind; expected != actual {
+		t.Fatalf("expected '%s', got '%s'", expected, actual)
+	}
+}