fix(core): cleanup testability subscriptions (#61261)

arturovt · thePunderWoman · commit 6bf6dbc37e2b · 2025-05-21T12:06:23.000Z
This commit prevents leaking memory when the application is destroyed and subscriptions are still alive. PR Close #61261
diff --git a/goldens/size-tracking/integration-payloads.json b/goldens/size-tracking/integration-payloads.json
@@ -1,8 +1,8 @@
 {
   "cli-hello-world": {
     "uncompressed": {
-      "main": 132425,
-      "polyfills": 33792
+      "main": 137461,
+      "polyfills": 34579
     }
   },
   "cli-hello-world-ivy-i18n": {
diff --git a/packages/core/src/testability/testability.ts b/packages/core/src/testability/testability.ts
@@ -6,7 +6,9 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import {Inject, Injectable, InjectionToken} from '../di';
+import {inject, Inject, Injectable, InjectionToken} from '../di';
+import {isInInjectionContext} from '../di/contextual';
+import {DestroyRef} from '../linker/destroy_ref';
 import {NgZone} from '../zone/ng_zone';
 
 /**
@@ -84,13 +86,21 @@ export class Testability implements PublicTestability {
   private _isZoneStable: boolean = true;
   private _callbacks: WaitCallback[] = [];
 
-  private taskTrackingZone: {macroTasks: Task[]} | null = null;
+  private _taskTrackingZone: {macroTasks: Task[]} | null = null;
+
+  private _destroyRef?: DestroyRef;
 
   constructor(
     private _ngZone: NgZone,
     private registry: TestabilityRegistry,
     @Inject(TESTABILITY_GETTER) testabilityGetter: GetTestability,
   ) {
+    // Attempt to retrieve a `DestroyRef` optionally.
+    // For backwards compatibility reasons, this cannot be required.
+    if (isInInjectionContext()) {
+      this._destroyRef = inject(DestroyRef, {optional: true}) ?? undefined;
+    }
+
     // If there was no Testability logic registered in the global scope
     // before, register the current testability getter as a global one.
     if (!_testabilityGetter) {
@@ -99,19 +109,19 @@ export class Testability implements PublicTestability {
     }
     this._watchAngularEvents();
     _ngZone.run(() => {
-      this.taskTrackingZone =
+      this._taskTrackingZone =
         typeof Zone == 'undefined' ? null : Zone.current.get('TaskTrackingZone');
     });
   }
 
   private _watchAngularEvents(): void {
-    this._ngZone.onUnstable.subscribe({
+    const onUnstableSubscription = this._ngZone.onUnstable.subscribe({
       next: () => {
         this._isZoneStable = false;
       },
     });
 
-    this._ngZone.runOutsideAngular(() => {
+    const onStableSubscription = this._ngZone.runOutsideAngular(() =>
       this._ngZone.onStable.subscribe({
         next: () => {
           NgZone.assertNotInAngularZone();
@@ -120,7 +130,12 @@ export class Testability implements PublicTestability {
             this._runCallbacksIfReady();
           });
         },
-      });
+      }),
+    );
+
+    this._destroyRef?.onDestroy(() => {
+      onUnstableSubscription.unsubscribe();
+      onStableSubscription.unsubscribe();
     });
   }
 
@@ -156,12 +171,12 @@ export class Testability implements PublicTestability {
   }
 
   private getPendingTasks(): PendingMacrotask[] {
-    if (!this.taskTrackingZone) {
+    if (!this._taskTrackingZone) {
       return [];
     }
 
     // Copy the tasks data so that we don't leak tasks.
-    return this.taskTrackingZone.macroTasks.map((t: Task) => {
+    return this._taskTrackingZone.macroTasks.map((t: Task) => {
       return {
         source: t.source,
         // From TaskTrackingZone:
@@ -196,7 +211,7 @@ export class Testability implements PublicTestability {
    *    and no further updates will be issued.
    */
   whenStable(doneCb: Function, timeout?: number, updateCb?: Function): void {
-    if (updateCb && !this.taskTrackingZone) {
+    if (updateCb && !this._taskTrackingZone) {
       throw new Error(
         'Task tracking zone is required when passing an update callback to ' +
           'whenStable(). Is "zone.js/plugins/task-tracking" loaded?',
diff --git a/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json b/packages/core/test/bundling/forms_reactive/bundle.golden_symbols.json
@@ -459,6 +459,7 @@
   "isFormControlState",
   "isForwardRef",
   "isFunction",
+  "isInInjectionContext",
   "isInlineTemplate",
   "isInputBinding",
   "isInteropObservable",
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
@@ -446,6 +446,7 @@
   "isFormControlState",
   "isForwardRef",
   "isFunction",
+  "isInInjectionContext",
   "isInlineTemplate",
   "isInputBinding",
   "isInteropObservable",

Original file line number	Diff line number	Diff line change
`@@ -1,8 +1,8 @@`
`1`	`1`	`{`
`2`	`2`	`"cli-hello-world": {`
`3`	`3`	`"uncompressed": {`
`4`		`- "main": 132425,`
`5`		`- "polyfills": 33792`
	`4`	`+ "main": 137461,`
	`5`	`+ "polyfills": 34579`
`6`	`6`	`}`
`7`	`7`	`},`
`8`	`8`	`"cli-hello-world-ivy-i18n": {`