Fixes from review

Author: joeycumines

kyaml/yaml/rnode.go

@@ -718,10 +718,11 @@ func (rn *RNode) MustString() string {
 
 // Content returns Node Content field.
 func (rn *RNode) Content() []*yaml.Node {
-	if yNode := rn.YNode(); yNode != nil {
-		return yNode.Content
+	yNode := rn.YNode()
+	if yNode == nil {
+		return nil
 	}
-	return nil
+	return yNode.Content
 }
 
 // Fields returns the list of field names for a MappingNode.
@@ -756,17 +757,18 @@ func (rn *RNode) FieldRNodes() ([]*RNode, error) {
 // Field returns a fieldName, fieldValue pair for MappingNodes.
 // Returns nil for non-MappingNodes.
 func (rn *RNode) Field(field string) *MapNode {
-	if yNode := rn.YNode(); yNode != nil {
-		if yNode.Kind != yaml.MappingNode {
-			return nil
-		}
-		var result *MapNode
-		visitMappingNodeFields(rn.Content(), func(key, value *yaml.Node) {
-			result = &MapNode{Key: NewRNode(key), Value: NewRNode(value)}
-		}, field)
-		return result
+	yNode := rn.YNode()
+	if yNode == nil {
+		return nil
 	}
-	return nil
+	if yNode.Kind != yaml.MappingNode {
+		return nil
+	}
+	var result *MapNode
+	visitMappingNodeFields(rn.Content(), func(key, value *yaml.Node) {
+		result = &MapNode{Key: NewRNode(key), Value: NewRNode(value)}
+	}, field)
+	return result
 }
 
 // VisitFields calls fn for each field in the RNode.
@@ -895,34 +897,36 @@ func (rn *RNode) ElementValuesList(keys []string) ([][]string, error) {
 // Element returns the element in the list which contains the field matching the value.
 // Returns nil for non-SequenceNodes or if no Element matches.
 func (rn *RNode) Element(key, value string) *RNode {
-	if yNode := rn.YNode(); yNode != nil {
-		if yNode.Kind != yaml.SequenceNode {
-			return nil
-		}
-		elem, err := rn.Pipe(MatchElement(key, value))
-		if err != nil {
-			return nil
-		}
-		return elem
+	yNode := rn.YNode()
+	if yNode == nil {
+		return nil
 	}
-	return nil
+	if yNode.Kind != yaml.SequenceNode {
+		return nil
+	}
+	elem, err := rn.Pipe(MatchElement(key, value))
+	if err != nil {
+		return nil
+	}
+	return elem
 }
 
 // ElementList returns the element in the list in which all fields keys[i] matches all
 // corresponding values[i].
 // Returns nil for non-SequenceNodes or if no Element matches.
 func (rn *RNode) ElementList(keys []string, values []string) *RNode {
-	if yNode := rn.YNode(); yNode != nil {
-		if yNode.Kind != yaml.SequenceNode {
-			return nil
-		}
-		elem, err := rn.Pipe(MatchElementList(keys, values))
-		if err != nil {
-			return nil
-		}
-		return elem
+	yNode := rn.YNode()
+	if yNode == nil {
+		return nil
 	}
-	return nil
+	if yNode.Kind != yaml.SequenceNode {
+		return nil
+	}
+	elem, err := rn.Pipe(MatchElementList(keys, values))
+	if err != nil {
+		return nil
+	}
+	return elem
 }
 
 // VisitElements calls fn for each element in a SequenceNode.
@@ -969,27 +973,30 @@ func (rn *RNode) GetAssociativeKey() string {
 
 // MarshalJSON creates a byte slice from the RNode.
 func (rn *RNode) MarshalJSON() ([]byte, error) {
-	if yNode := rn.YNode(); yNode != nil {
-		s, err := rn.String()
-		if err != nil {
-			return nil, err
-		}
+	yNode := rn.YNode()
+	if yNode == nil {
+		return []byte("null"), nil
+	}
 
-		if yNode.Kind == SequenceNode {
-			var a []interface{}
-			if err := Unmarshal([]byte(s), &a); err != nil {
-				return nil, err
-			}
-			return json.Marshal(a)
-		}
+	s, err := rn.String()
+	if err != nil {
+		return nil, err
+	}
 
-		m := map[string]interface{}{}
-		if err := Unmarshal([]byte(s), &m); err != nil {
+	if yNode.Kind == SequenceNode {
+		var a []interface{}
+		if err := Unmarshal([]byte(s), &a); err != nil {
 			return nil, err
 		}
-		return json.Marshal(m)
+		return json.Marshal(a)
+	}
+
+	m := map[string]interface{}{}
+	if err := Unmarshal([]byte(s), &m); err != nil {
+		return nil, err
 	}
-	return json.Marshal(nil)
+
+	return json.Marshal(m)
 }
 
 // UnmarshalJSON overwrites this RNode with data from []byte.