Add test for builtin secretgenerator plugin.

pkg/resmap/legacygeneratorargs.go

@@ -0,0 +1,26 @@
+package resmap
+
+import (
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/types"
+)
+
+func GeneratorArgsFromKunstruct(k ifc.Kunstructured) (
+	result types.GeneratorArgs, err error) {
+	result.Name = k.GetName()
+	// TODO: validate behavior values.
+	result.Behavior, err = k.GetFieldValue("behavior")
+	if err != nil {
+		return
+	}
+	result.EnvSources, err = k.GetStringSlice("envFiles")
+	if err != nil {
+		return
+	}
+	result.FileSources, err = k.GetStringSlice("valueFiles")
+	if err != nil {
+		return
+	}
+	result.LiteralSources, err = k.GetStringSlice("literals")
+	return
+}