Merge pull request #34 from ryansb/bug/metadataSerialization

Fix instance metadata XML serialization

Author: ryansb

marshal.go

@@ -4,6 +4,7 @@ package fargo
 
 import (
 	"encoding/json"
+	"encoding/xml"
 	"strconv"
 )
 
@@ -120,3 +121,26 @@ func (i *InstanceMetadata) MarshalJSON() ([]byte, error) {
 
 	return i.Raw, nil
 }
+
+// MarshalXML is a custom XML marshaler for InstanceMetadata.
+func (i InstanceMetadata) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
+	tokens := []xml.Token{start}
+
+	if i.parsed != nil {
+		for key, value := range i.parsed {
+			t := xml.StartElement{Name: xml.Name{"", key}}
+			tokens = append(tokens, t, xml.CharData(value.(string)), xml.EndElement{t.Name})
+		}
+	}
+	tokens = append(tokens, xml.EndElement{start.Name})
+
+	for _, t := range tokens {
+		err := e.EncodeToken(t)
+		if err != nil {
+			return err
+		}
+	}
+
+	// flush to ensure tokens are written
+	return e.Flush()
+}

tests/metadata_test.go

@@ -3,6 +3,7 @@ package fargo_test
 // MIT Licensed (see README.md) - Copyright (c) 2013 Hudl <@Hudl>
 
 import (
+	"encoding/xml"
 	"github.com/hudl/fargo"
 	. "github.com/smartystreets/goconvey/convey"
 	"strconv"
@@ -58,3 +59,28 @@ func TestGetFloat(t *testing.T) {
 		})
 	})
 }
+
+func TestSerializeMeta(t *testing.T) {
+	Convey("Given an instance", t, func() {
+		instance := new(fargo.Instance)
+		Convey("With metadata", func() {
+			instance.SetMetadataString("test", "value")
+			Convey("Serializing results in correct JSON", func() {
+				b, err := instance.Metadata.MarshalJSON()
+				So(err, ShouldBeNil)
+				So(string(b), ShouldEqual, "{\"test\":\"value\"}")
+			})
+			Convey("Serializing results in correct XML", func() {
+				b, err := xml.Marshal(instance.Metadata)
+				So(err, ShouldBeNil)
+				So(string(b), ShouldEqual, "<InstanceMetadata><test>value</test></InstanceMetadata>")
+			})
+			Convey("Blank metadata results in blank XML", func() {
+				metadata := new(fargo.InstanceMetadata)
+				b, err := xml.Marshal(metadata)
+				So(err, ShouldBeNil)
+				So(string(b), ShouldEqual, "<InstanceMetadata></InstanceMetadata>")
+			})
+		})
+	})
+}