return history properly sorted

check/main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"os"
+	"sort"
 
 	resource "github.com/cioplenu/concourse-nomad-resource"
 	"github.com/cioplenu/concourse-nomad-resource/common"
@@ -21,16 +22,19 @@ func main() {
 	lastVersion := request.Version.Version
 
 	history := common.GetHistory(request.Source)
+	sort.Sort(history) // Nomad provides history from newest to oldest
 	versions := make([]resource.Version, 0)
 
-	for _, jobVersion := range history {
+	for i, jobVersion := range history {
+		// Only return the current version and newer ones
 		if lastVersion != 0 && lastVersion > jobVersion.Version {
 			continue
 		}
-		versions = append(versions, resource.Version{jobVersion.Version})
-		if lastVersion == 0 {
-			break
+		// If no version was provided return only the latest
+		if lastVersion == 0 && i < len(history)-1 {
+			continue
 		}
+		versions = append(versions, resource.Version{jobVersion.Version})
 	}
 
 	json.NewEncoder(os.Stdout).Encode(versions)

common/common.go

@@ -17,7 +17,7 @@ func Check(err error, msg string) {
 	}
 }
 
-func GetHistory(source resource.Source) []resource.JobVersion {
+func GetHistory(source resource.Source) resource.History {
 	cmd := exec.Command(
 		"nomad",
 		"job",

models.go

@@ -12,6 +12,12 @@ type JobVersion struct {
 	SubmitTime int
 }
 
+type History []JobVersion
+
+func (h History) Len() int           { return len(h) }
+func (h History) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }
+func (h History) Less(i, j int) bool { return h[i].Version < h[j].Version }
+
 type Version struct {
 	Version int `json:"Version,string"`
 }