From 91aafe7365da4c78b28e1c3d10f120f1eed74297 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Flemstr=C3=B6m?= <david.flemstrom@gmail.com>
Date: Thu, 13 Aug 2020 14:15:38 +0200
Subject: [PATCH 1/2] Avoid emitting YAML back-references in kpt fn output

---
 ts/kpt-functions/src/io.ts      |  2 +
 ts/kpt-functions/src/io_test.ts | 68 ++++++++++++++++++++++++++++++++-
 ts/kpt-functions/src/types.ts   |  6 +--
 3 files changed, 72 insertions(+), 4 deletions(-)

diff --git a/ts/kpt-functions/src/io.ts b/ts/kpt-functions/src/io.ts
index 6eceb8540..78bdf5dc6 100644
--- a/ts/kpt-functions/src/io.ts
+++ b/ts/kpt-functions/src/io.ts
@@ -38,6 +38,8 @@ const YAML_STYLE: DumpOptions = {
   skipInvalid: true,
   // unset lineWidth from default of 80 to avoid reformatting
   lineWidth: -1,
+  // avoid refs because many YAML parsers in the k8s ecosystem don't support them
+  noRefs: true,
 };
 
 /**
diff --git a/ts/kpt-functions/src/io_test.ts b/ts/kpt-functions/src/io_test.ts
index f775ab985..136e95649 100644
--- a/ts/kpt-functions/src/io_test.ts
+++ b/ts/kpt-functions/src/io_test.ts
@@ -15,7 +15,8 @@
  */
 
 import { FileFormat, parse, stringify } from './io';
-import { Configs, KubernetesObject } from './types';
+import { Configs, JsonArray, KubernetesObject } from './types';
+import { kubernetesObjectResult } from './result';
 
 describe('read', () => {
   describe('in YAML format', () => {
@@ -686,3 +687,68 @@ results:
     });
   });
 });
+
+describe('roundtrip', () => {
+  describe('using YAML', () => {
+    it('should not insert YAML references', () => {
+      interface Baz {
+        baz: number;
+      }
+
+      interface Foo extends KubernetesObject {
+        spec: {
+          array: Baz[];
+        };
+      }
+
+      const input =
+        'items: [{apiVersion: v1, kind: Foo, metadata: {name: bar}, spec: {array: [{baz: 1}]}}]';
+      const configs = parse(input, FileFormat.YAML);
+
+      const foo = configs.getAll()[0] as Foo;
+      configs.addResults(
+        kubernetesObjectResult('something is wrong', foo, {
+          path: 'spec.array',
+          // Note: we re-use objects from the input to trigger YAML refs to normally be created
+          currentValue: (foo.spec.array as unknown) as JsonArray,
+          suggestedValue: (foo.spec.array.concat([
+            { baz: 3 },
+          ]) as unknown) as JsonArray,
+        })
+      );
+
+      const stringified = stringify(configs, FileFormat.YAML);
+
+      // We want to verify that there are no back-references like &ref and *ref in the output
+      expect(stringified).toEqual(`apiVersion: v1
+kind: ResourceList
+metadata:
+  name: output
+items:
+- apiVersion: v1
+  kind: Foo
+  metadata:
+    name: bar
+  spec:
+    array:
+    - baz: 1
+results:
+- message: something is wrong
+  severity: error
+  resourceRef:
+    apiVersion: v1
+    kind: Foo
+    namespace: ''
+    name: bar
+  file: {}
+  field:
+    path: spec.array
+    currentValue:
+    - baz: 1
+    suggestedValue:
+    - baz: 1
+    - baz: 3
+`);
+    });
+  });
+});
diff --git a/ts/kpt-functions/src/types.ts b/ts/kpt-functions/src/types.ts
index 972630ce3..5d7dc4264 100644
--- a/ts/kpt-functions/src/types.ts
+++ b/ts/kpt-functions/src/types.ts
@@ -403,13 +403,13 @@ export interface Result {
  */
 export type Severity = 'error' | 'warn' | 'info';
 
-interface JsonArray extends Array<Json> {}
+export interface JsonArray extends Array<Json> {}
 
-interface JsonMap {
+export interface JsonMap {
   [field: string]: Json;
 }
 
-type Json = null | boolean | number | string | JsonArray | JsonMap;
+export type Json = null | boolean | number | string | JsonArray | JsonMap;
 
 /**
  * Metadata about a specific field in a Kubernetes object.

From ff17d67701655aa0f5195cce8d498bf8e053161d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Flemstr=C3=B6m?= <david.flemstrom@gmail.com>
Date: Wed, 19 Aug 2020 09:26:07 +0200
Subject: [PATCH 2/2] Add comments to exported types

---
 ts/kpt-functions/src/types.ts | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/ts/kpt-functions/src/types.ts b/ts/kpt-functions/src/types.ts
index 5d7dc4264..e118d0df6 100644
--- a/ts/kpt-functions/src/types.ts
+++ b/ts/kpt-functions/src/types.ts
@@ -403,12 +403,15 @@ export interface Result {
  */
 export type Severity = 'error' | 'warn' | 'info';
 
+/** A plain old JSON array according to ECMA-404. */
 export interface JsonArray extends Array<Json> {}
 
+/** A plain old JSON object/map according to ECMA-404. */
 export interface JsonMap {
   [field: string]: Json;
 }
 
+/** Any plain old JSON value according to ECMA-404. */
 export type Json = null | boolean | number | string | JsonArray | JsonMap;
 
 /**