add test

Author: Mengqi Yu

tests/starlark/preserve-id-annotations/.expected/diff.patch

@@ -0,0 +1,32 @@
+diff --git a/app.yaml b/app.yaml
+index f821124..4cf1245 100644
+--- a/app.yaml
++++ b/app.yaml
+@@ -2,6 +2,7 @@ apiVersion: v1
+ kind: ConfigMap
+ metadata:
+   name: my-cm
++  namespace: prod
+   annotations:
+     config.k8s.io/id: "1"
+ data:
+@@ -11,6 +12,7 @@ apiVersion: foo.com/v1
+ kind: Bar
+ metadata:
+   name: my-bar
++  namespace: prod
+   annotations:
+     config.k8s.io/id: "2"
+ spec:
+diff --git a/fn-config.yaml b/fn-config.yaml
+index 5b8d869..eddef45 100644
+--- a/fn-config.yaml
++++ b/fn-config.yaml
+@@ -2,6 +2,7 @@ apiVersion: fn.kpt.dev/v1alpha1
+ kind: StarlarkRun
+ metadata:
+   name: set-namespace-to-prod
++  namespace: prod
+   annotations:
+     config.k8s.io/id: "3"
+ source: |

tests/starlark/preserve-id-annotations/.expected/exec.sh

@@ -0,0 +1,13 @@
+#! /bin/bash
+
+set -euo pipefail
+
+rm -rf new-dir
+
+# We are not using eval here, since eval will also touch id annotation.
+# We want to ensure the starlark function doesn't touch id annotations.
+# fn sink doesn't allow us to write to existing directory, so we write a
+# different directory and then copy the files.
+kpt fn source --fn-config fn-config.yaml | docker run -i gcr.io/kpt-fn/starlark:unstable | docker run -i gcr.io/kpt-fn/format:v0.1 | kpt fn sink new-dir
+mv new-dir/* .
+rm -rf new-dir

tests/starlark/preserve-id-annotations/.krmignore

@@ -0,0 +1 @@
+.expected

tests/starlark/preserve-id-annotations/app.yaml

@@ -0,0 +1,17 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: my-cm
+  annotations:
+    config.k8s.io/id: "1"
+data:
+  some-key: some-value
+---
+apiVersion: foo.com/v1
+kind: Bar
+metadata:
+  name: my-bar
+  annotations:
+    config.k8s.io/id: "2"
+spec:
+  featureA: true

tests/starlark/preserve-id-annotations/fn-config.yaml

@@ -0,0 +1,13 @@
+apiVersion: fn.kpt.dev/v1alpha1
+kind: StarlarkRun
+metadata:
+  name: set-namespace-to-prod
+  annotations:
+    config.k8s.io/id: "3"
+source: |
+  # set the namespace on all resources
+  def setnamespace(resources, namespace):
+    for resource in resources:
+      # mutate the resource
+      resource["metadata"]["namespace"] = namespace
+  setnamespace(ctx.resource_list["items"], "prod")