Implement replica transformer as patch alternative

plugin/builtin/replicacounttransformer/ReplicaCountTransformer_test.go

@@ -0,0 +1,49 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package main_test
+
+import (
+	"testing"
+
+	"sigs.k8s.io/kustomize/pkg/kusttest"
+	"sigs.k8s.io/kustomize/plugin"
+)
+
+func TestReplicaCountTransformer(t *testing.T) {
+	tc := plugin.NewEnvForTest(t).Set()
+	defer tc.Reset()
+
+	tc.BuildGoPlugin(
+		"builtin", "", "ReplicaCountTransformer")
+
+	th := kusttest_test.NewKustTestPluginHarness(t, "/app")
+
+	rm := th.LoadAndRunTransformer(`
+apiVersion: builtin
+kind: ReplicaCountTransformer
+metadata:
+  name: notImportantHere
+replica:
+  name: deploy1
+  count: 23
+`, `
+group: apps
+apiVersion: v1
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  replicas: 1
+`)
+
+	th.AssertActualEqualsExpected(rm, `
+apiVersion: v1
+group: apps
+kind: Deployment
+metadata:
+  name: deploy1
+spec:
+  replicas: 23
+`)
+}