From e13f8803eba57f3bb3d8b108ffffd264d50cdb5d Mon Sep 17 00:00:00 2001
From: Mikhail Nikitin <mikhail.nikitin@ispringsolutions.com>
Date: Fri, 15 Jan 2021 00:08:49 +0300
Subject: [PATCH] Add test case of deleting not existing elements

---
 api/krusty/patchdelete_test.go | 96 ++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 api/krusty/patchdelete_test.go

diff --git a/api/krusty/patchdelete_test.go b/api/krusty/patchdelete_test.go
new file mode 100644
index 000000000..65a6954cd
--- /dev/null
+++ b/api/krusty/patchdelete_test.go
@@ -0,0 +1,96 @@
+package krusty_test
+
+import (
+	"testing"
+
+	kusttest_test "sigs.k8s.io/kustomize/api/testutils/kusttest"
+)
+
+func TestPatchDeleteOfNotExistingAttributesShouldNotAddExtraElements(t *testing.T) {
+	th := kusttest_test.MakeEnhancedHarness(t)
+	defer th.Reset()
+
+	th.WriteF("/app/resource.yaml", `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: whatever
+spec:
+  template:
+    spec:
+      containers:
+      - env:
+        - name: EXISTING
+          value: EXISTING_VALUE
+        - name: FOR_REMOVAL
+          value: FOR_REMOVAL_VALUE
+        name: whatever
+        image: helloworld
+`)
+	th.WriteF("/app/patch.yml", `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: whatever
+spec:
+  template:
+    spec:
+      containers:
+      - name: whatever
+        env:
+        - name: FOR_REMOVAL
+          $patch: delete
+        - name: NOT_EXISTING_FOR_REMOVAL
+          $patch: delete
+`)
+	th.WriteK("/app", `
+resources:
+- resource.yaml
+patches:
+- path: patch.yml
+  target:
+    kind: Deployment
+`)
+
+	/*
+		// It's expected that removal of not existing elements should not introduce extra values,
+		// as a patch can be applied to multipe resources, not all of them can have all deleted elements.
+		expected := `
+	apiVersion: apps/v1
+	kind: Deployment
+	metadata:
+	  name: whatever
+	spec:
+	  template:
+	    spec:
+	      containers:
+	      - env:
+	        - name: EXISTING
+	          value: EXISTING_VALUE
+	        image: helloworld
+	        name: whatever
+	`
+	*/
+
+	// Currently kustomize inserts $patch: delete elements into the resulting resources
+	erroneousActual := `
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: whatever
+spec:
+  template:
+    spec:
+      containers:
+      - env:
+        - $patch: delete
+          name: NOT_EXISTING_FOR_REMOVAL
+        - name: EXISTING
+          value: EXISTING_VALUE
+        image: helloworld
+        name: whatever
+`
+
+	m := th.Run("/app", th.MakeDefaultOptions())
+	th.AssertActualEqualsExpected(m, erroneousActual)
+}