Add ToYAML function to Marshal

Author: Antoine Pelisse

internal/cli/operation.go

@@ -21,8 +21,8 @@ import (
 	"io"
 	"io/ioutil"
 
-	"gopkg.in/yaml.v2"
 	"sigs.k8s.io/structured-merge-diff/typed"
+	"sigs.k8s.io/structured-merge-diff/value"
 )
 
 type Operation interface {
@@ -114,7 +114,7 @@ func (m merge) Execute(w io.Writer) error {
 		return err
 	}
 
-	yaml, err := yaml.Marshal(out.AsValue().Unstructured())
+	yaml, err := value.ToYAML(out.AsValue())
 	if err != nil {
 		return err
 	}

value/value.go

@@ -23,6 +23,7 @@ import (
 	"strings"
 
 	jsoniter "github.com/json-iterator/go"
+	"gopkg.in/yaml.v2"
 )
 
 var (
@@ -118,6 +119,11 @@ func WriteJSONStream(v Value, stream *jsoniter.Stream) {
 	stream.WriteVal(v.Unstructured())
 }
 
+// ToYAML marshals a value as YAML.
+func ToYAML(v Value) ([]byte, error) {
+	return yaml.Marshal(v.Unstructured())
+}
+
 // Equals returns true iff the two values are equal.
 func Equals(lhs, rhs Value) bool {
 	if lhs.IsFloat() || rhs.IsFloat() {