add ability to pass --purge to delete

main.go

@@ -129,6 +129,11 @@ func main() {
 			Usage:  "force resource update through delete/recreate if needed",
 			EnvVar: "PLUGIN_FORCE,FORCE",
 		},
+		cli.BoolFlag{
+			Name:   "purge",
+			Usage:  "purge on delete",
+			EnvVar: "PLUGIN_PURGE,PURGE",
+		},
 	}
 	if err := app.Run(os.Args); err != nil {
 		logrus.Fatal(err)

plugin.go

@@ -45,6 +45,7 @@ type (
 		Timeout        string   `json:"timeout"`
 		Force          bool     `json:"force"`
 		HelmRepos      []string `json:"helm_repos"`
+		Purge          bool     `json:"purge"`
 	}
 	// Plugin default
 	Plugin struct {
@@ -68,6 +69,9 @@ func setDeleteCommand(p *Plugin) {
 	if p.Config.DryRun {
 		delete = append(delete, "--dry-run")
 	}
+	if p.Config.Purge {
+		delete = append(delete, "--purge")
+	}
 
 	p.command = delete
 }

plugin_test.go

@@ -139,11 +139,12 @@ func TestGetHelmDeleteCommandOverried(t *testing.T) {
 			Release:       "test-release",
 			Values:        "image.tag=v.0.1.0,nameOverride=my-over-app",
 			Wait:          true,
+			Purge:         true,
 		},
 	}
 	setHelmCommand(plugin)
 	res := strings.Join(plugin.command[:], " ")
-	expected := "delete test-release --tiller-namespace default-tiller-ns --dry-run"
+	expected := "delete test-release --tiller-namespace default-tiller-ns --dry-run --purge"
 	if res != expected {
 		t.Errorf("Result is %s and we expected %s", res, expected)
 	}