hide patch transformer behind interface

pkg/ifc/patch/patch.go

@@ -0,0 +1,28 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package patch holds miscellaneous interfaces used by kustomize.
+package patch
+
+import (
+	"sigs.k8s.io/kustomize/pkg/resource"
+	"sigs.k8s.io/kustomize/pkg/transformers"
+)
+
+// PatchTransformerFactory makes patch transformer.
+type PatchTransformerFactory interface {
+	MakePatchTransformer(slice []*resource.Resource, rf *resource.Factory) (transformers.Transformer, error)
+}