kyaml: rename annotations and fix linting

kyaml/yaml/alias.go

@@ -22,7 +22,7 @@ type TypeError = yaml.TypeError
 type Unmarshaler = yaml.Unmarshaler
 
 var Marshal = yaml.Marshal
-var UnMarshal = yaml.Unmarshal
+var Unmarshal = yaml.Unmarshal
 var NewDecoder = yaml.NewDecoder
 var NewEncoder = func(w io.Writer) *yaml.Encoder {
 	e := yaml.NewEncoder(w)

kyaml/yaml/filters.go

@@ -46,7 +46,8 @@ func (y *YFilter) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	if err := unmarshal(meta); err != nil {
 		return err
 	}
-	if filter, found := Filters[meta.Kind]; !found {
+	filter, found := Filters[meta.Kind]
+	if !found {
 		var knownFilters []string
 		for k := range Filters {
 			knownFilters = append(knownFilters, k)
@@ -54,9 +55,9 @@ func (y *YFilter) UnmarshalYAML(unmarshal func(interface{}) error) error {
 		sort.Strings(knownFilters)
 		return fmt.Errorf("unsupported GrepFilter Kind %s:  may be one of: [%s]",
 			meta.Kind, strings.Join(knownFilters, ","))
-	} else {
-		y.Filter = filter()
 	}
+	y.Filter = filter()
+
 	if err := unmarshal(y.Filter); err != nil {
 		return err
 	}

kyaml/yaml/match.go

@@ -82,10 +82,9 @@ func (p *PathMatcher) filter(rn *RNode) (*RNode, error) {
 	if IsListIndex(p.Path[0]) {
 		// match seq elements
 		return p.doSeq(rn)
-	} else {
-		// match a field
-		return p.doField(rn)
 	}
+	// match a field
+	return p.doField(rn)
 }
 
 func (p *PathMatcher) doField(rn *RNode) (*RNode, error) {

kyaml/yaml/types.go

@@ -240,7 +240,7 @@ type ObjectMeta struct {
 	Annotations map[string]string `yaml:"annotations,omitempty"`
 }
 
-var MissingMetaError = errors.New("missing Resource metadata")
+var ErrMissingMetadata = errors.New("missing Resource metadata")
 
 // GetMeta returns the ResourceMeta for a RNode
 func (rn *RNode) GetMeta() (ResourceMeta, error) {
@@ -259,7 +259,7 @@ func (rn *RNode) GetMeta() (ResourceMeta, error) {
 		return m, err
 	}
 	if reflect.DeepEqual(m, ResourceMeta{}) {
-		return m, MissingMetaError
+		return m, ErrMissingMetadata
 	}
 	return m, nil
 }
@@ -298,6 +298,13 @@ func (rn *RNode) Pipe(functions ...Filter) (*RNode, error) {
 	return v, err
 }
 
+// PipeE runs Pipe, dropping the *RNode return value.
+// Useful for directly returning the Pipe error value from functions.
+func (rn *RNode) PipeE(functions ...Filter) error {
+	_, err := rn.Pipe(functions...)
+	return err
+}
+
 // Document returns the Node RNode for the value.  Does not unwrap the node if it is a
 // DocumentNodes
 func (rn *RNode) Document() *yaml.Node {
@@ -445,7 +452,7 @@ func (rn *RNode) Elements() ([]*RNode, error) {
 		return nil, err
 	}
 	var elements []*RNode
-	for i := 0; i < len(rn.Content()); i += 1 {
+	for i := 0; i < len(rn.Content()); i++ {
 		elements = append(elements, NewRNode(rn.Content()[i]))
 	}
 	return elements, nil
@@ -459,7 +466,7 @@ func (rn *RNode) ElementValues(key string) ([]string, error) {
 		return nil, err
 	}
 	var elements []string
-	for i := 0; i < len(rn.Content()); i += 1 {
+	for i := 0; i < len(rn.Content()); i++ {
 		field := NewRNode(rn.Content()[i]).Field(key)
 		if !IsFieldEmpty(field) {
 			elements = append(elements, field.Value.YNode().Value)
@@ -497,8 +504,7 @@ func (rn *RNode) VisitElements(fn func(node *RNode) error) error {
 	return nil
 }
 
-// AssociativeSequencePaths is a list of field names that may be used as associative keys
-// when merge Resources.
+// AssociativeSequenceKeys is a map of paths to sequences that have associative keys.
 // The order sets the precedence of the merge keys -- if multiple keys are present
 // in Resources in a list, then the FIRST key which ALL elements in the list have is used as the
 // associative key for merging that list.

kyaml/yaml/walk/associative_sequence.go

@@ -24,10 +24,7 @@ func (l *Walker) walkAssociativeSequence() (*yaml.RNode, error) {
 	if err != nil {
 		return nil, err
 	}
-	values, err := l.elementValues(key)
-	if err != nil {
-		return nil, err
-	}
+	values := l.elementValues(key)
 
 	// recursively set the elements in the list
 	for _, value := range values {
@@ -90,7 +87,7 @@ func (l Walker) elementKey() (string, error) {
 // from all sources.
 // Return value slice is ordered using the original ordering from the elements, where
 // elements missing from earlier sources appear later.
-func (l Walker) elementValues(key string) ([]string, error) {
+func (l Walker) elementValues(key string) []string {
 	// use slice to to keep elements in the original order
 	// dest node must be first
 	var returnValues []string
@@ -111,7 +108,7 @@ func (l Walker) elementValues(key string) ([]string, error) {
 			seen.Insert(s)
 		}
 	}
-	return returnValues, nil
+	return returnValues
 }
 
 // fieldValue returns a slice containing each source's value for fieldName

kyaml/yaml/walk/visitor.go

@@ -1,16 +1,5 @@
-// Copyright 2019 Google LLC
-//
-// 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.
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
 
 package walk
 
@@ -34,5 +23,5 @@ type Visitor interface {
 	VisitList(nodes Sources, kind ListKind) (*yaml.RNode, error)
 }
 
-// NoOp is returned if GrepFilter should do nothing after calling Set
-var ClearNode *yaml.RNode = nil
+// ClearNode is returned if GrepFilter should do nothing after calling Set
+var ClearNode *yaml.RNode

kyaml/yaml/walk/walk.go

@@ -48,9 +48,9 @@ func (l Walker) Walk() (*yaml.RNode, error) {
 		}
 		if yaml.IsAssociative(l.Sources) {
 			return l.walkAssociativeSequence()
-		} else {
-			return l.walkNonAssociativeSequence()
 		}
+		return l.walkNonAssociativeSequence()
+
 	case yaml.ScalarNode:
 		if err := yaml.ErrorIfAnyInvalidAndNonNull(yaml.ScalarNode, l.Sources...); err != nil {
 			return nil, err