From 2d3a689660c1af5d7ecce33ea0bd72a04eee748a Mon Sep 17 00:00:00 2001
From: Alan Agius <alanagius@google.com>
Date: Tue, 22 Oct 2024 08:56:51 +0000
Subject: [PATCH] =?UTF-8?q?refactor(core):=20eliminate=20top-level=20prope?=
 =?UTF-8?q?rty=20access=20in=20`=C9=B5=C9=B5NgOnChangesFeature`=20(#58297)?=
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Top-level property access was causing dead code elimination (DCE) and tree-shaking issues. This commit modifies `ɵɵNgOnChangesFeature` to prevent these bailouts.

PR Close #58297
---
 .../render3/features/ng_onchanges_feature.ts  | 19 ++++++++++---------
 .../forms_reactive/bundle.golden_symbols.json |  3 +++
 .../bundle.golden_symbols.json                |  3 +++
 .../router/bundle.golden_symbols.json         |  3 +++
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/packages/core/src/render3/features/ng_onchanges_feature.ts b/packages/core/src/render3/features/ng_onchanges_feature.ts
index 62b5ba6709a..636cd78c062 100644
--- a/packages/core/src/render3/features/ng_onchanges_feature.ts
+++ b/packages/core/src/render3/features/ng_onchanges_feature.ts
@@ -36,9 +36,16 @@ import {DirectiveDef, DirectiveDefFeature} from '../interfaces/definition';
  *
  * @codeGenApi
  */
-export function ɵɵNgOnChangesFeature<T>(): DirectiveDefFeature {
-  return NgOnChangesFeatureImpl;
-}
+export const ɵɵNgOnChangesFeature: () => DirectiveDefFeature = /* @__PURE__ */ (() => {
+  const ɵɵNgOnChangesFeatureImpl = () => NgOnChangesFeatureImpl;
+
+  // This option ensures that the ngOnChanges lifecycle hook will be inherited
+  // from superclasses (in InheritDefinitionFeature).
+  /** @nocollapse */
+  ɵɵNgOnChangesFeatureImpl.ngInherit = true;
+
+  return ɵɵNgOnChangesFeatureImpl;
+})();
 
 export function NgOnChangesFeatureImpl<T>(definition: DirectiveDef<T>) {
   if (definition.type.prototype.ngOnChanges) {
@@ -47,12 +54,6 @@ export function NgOnChangesFeatureImpl<T>(definition: DirectiveDef<T>) {
   return rememberChangeHistoryAndInvokeOnChangesHook;
 }
 
-// This option ensures that the ngOnChanges lifecycle hook will be inherited
-// from superclasses (in InheritDefinitionFeature).
-/** @nocollapse */
-// tslint:disable-next-line:no-toplevel-property-access
-(ɵɵNgOnChangesFeature as DirectiveDefFeature).ngInherit = true;
-
 /**
  * This is a synthetic lifecycle hook which gets inserted into `TView.preOrderHooks` to simulate
  * `ngOnChanges`.
diff --git a/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json b/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json
index adb204a5386..f564737ae5f 100644
--- a/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json
@@ -434,6 +434,9 @@
   {
     "name": "NgModuleRef2"
   },
+  {
+    "name": "NgOnChangesFeatureImpl"
+  },
   {
     "name": "NgZone"
   },
diff --git a/packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json b/packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json
index d9b7adc2ebb..4607da7f952 100644
--- a/packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/forms_template_driven/bundle.golden_symbols.json
@@ -419,6 +419,9 @@
   {
     "name": "NgModuleRef2"
   },
+  {
+    "name": "NgOnChangesFeatureImpl"
+  },
   {
     "name": "NgZone"
   },
diff --git a/packages/core/test/bundling/router/bundle.golden_symbols.json b/packages/core/test/bundling/router/bundle.golden_symbols.json
index beb01ca95c3..c706459a367 100644
--- a/packages/core/test/bundling/router/bundle.golden_symbols.json
+++ b/packages/core/test/bundling/router/bundle.golden_symbols.json
@@ -455,6 +455,9 @@
   {
     "name": "NgModuleRef2"
   },
+  {
+    "name": "NgOnChangesFeatureImpl"
+  },
   {
     "name": "NgZone"
   },