refactor(platform-browser): log a warning when a custom or a noop ZoneJS is used with hydration (angular#49944)

Hydration relies on a signal from ZoneJS when it becomes stable inside an application, so that Angular can start serialization process on the server or post-hydration cleanup on the client (to remove DOM nodes that remained unclaimed).

Providing a custom or a "noop" ZoneJS implementation may lead to a different timing of the "stable" event, thus triggering the serialization or the cleanup too early or too late. This is not yet a fully supported configuration.

This commit adds a warning (non-blocking) for those cases.

PR Close angular#49944

Author: AndrewKushnir

aio/content/errors/NG5000.md

@@ -0,0 +1,14 @@
+@name Hydration with unsupported Zone.js instance.
+@category runtime
+@shortDescription Hydration was enabled with unsupported Zone.js instance.
+
+@description
+This warning means that the hydration was enabled for an application that was configured to use an unsupported version of Zone.js: either a custom or a "noop" one (see more info [here](api/core/BootstrapOptions#ngZone)).
+
+Hydration relies on a signal from Zone.js when it becomes stable inside an application, so that Angular can start the serialization process on the server or post-hydration cleanup on the client (to remove DOM nodes that remained unclaimed).
+
+Providing a custom or a "noop" Zone.js implementation may lead to a different timing of the "stable" event, thus triggering the serialization or the cleanup too early or too late. This is not yet a fully supported configuration.
+
+If you use a custom Zone.js implementation, make sure that the "onStable" event is emitted at the right time and does not result in incorrect application behavior with hydration.
+
+More information about hydration can be found in the [hydration guide](guide/hydration).

aio/content/guide/hydration.md

@@ -65,7 +65,7 @@ After you've followed these steps and have started up your server, load your app
 
 </div>
 
-You can confirm hydration is enabled by opening Developer Tools in your browser and viewing the console. You should see a message that includes hydration-related stats, such as the number of components and nodes hydrated. Note: Angular calculates the stats based on all components rendered on a page, including those that come from third-party libraries.
+While running an application in dev mode, you can confirm hydration is enabled by opening the Developer Tools in your browser and viewing the console. You should see a message that includes hydration-related stats, such as the number of components and nodes hydrated. Note: Angular calculates the stats based on all components rendered on a page, including those that come from third-party libraries.
 
 <a id="constraints"></a>
 
@@ -110,6 +110,13 @@ If you choose to set this setting in your tsconfig, we recommend to set it only
 
 </div>
 
+### Custom or Noop Zone.js are not yet supported
+
+Hydration relies on a signal from Zone.js when it becomes stable inside an application, so that Angular can start the serialization process on the server or post-hydration cleanup on the client to remove DOM nodes that remained unclaimed.
+
+Providing a custom or a "noop" Zone.js implementation may lead to a different timing of the "stable" event, thus triggering the serialization or the cleanup too early or too late. This is not yet a fully supported configuration and you may need to adjust the timing of the `onStable` event in the custom Zone.js implementation.
+
+
 <a id="errors"></a>
 
 ## Errors

goldens/public-api/platform-browser/errors.md

@@ -0,0 +1,15 @@
+## API Report File for "angular-srcs"
+
+> Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
+
+```ts
+
+// @public
+export const enum RuntimeErrorCode {
+    // (undocumented)
+    UNSUPPORTED_ZONEJS_INSTANCE = -5000
+}
+
+// (No @packageDocumentation comment for this package)
+
+```

packages/animations/browser/src/errors.ts

@@ -6,6 +6,10 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+/**
+ * The list of error codes used in runtime code of the `animations` package.
+ * Reserved error code range: 3000-3999.
+ */
 export const enum RuntimeErrorCode {
   // Invalid values
   INVALID_TIMING_VALUE = 3000,

packages/core/src/errors.ts

@@ -17,6 +17,14 @@ import {ERROR_DETAILS_PAGE_BASE_URL} from './error_details_base_url';
  * error codes which have guides, which might leak into runtime code.
  *
  * Full list of available error guides can be found at https://angular.io/errors.
+ *
+ * Error code ranges per package:
+ *  - core (this package): 100-999
+ *  - forms: 1000-1999
+ *  - common: 2000-2999
+ *  - animations: 3000-3999
+ *  - router: 4000-4999
+ *  - platform-browser: 5000-5500
  */
 export const enum RuntimeErrorCode {
   // Change Detection Errors

packages/platform-browser/BUILD.bazel

@@ -1,4 +1,4 @@
-load("//tools:defaults.bzl", "api_golden_test_npm_package", "ng_module", "ng_package", "tsec_test")
+load("//tools:defaults.bzl", "api_golden_test", "api_golden_test_npm_package", "ng_module", "ng_package", "tsec_test")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -62,6 +62,16 @@ api_golden_test_npm_package(
     npm_package = "angular/packages/platform-browser/npm_package",
 )
 
+api_golden_test(
+    name = "platform-browser_errors",
+    data = [
+        "//goldens:public-api",
+        "//packages/platform-browser",
+    ],
+    entry_point = "angular/packages/platform-browser/src/errors.d.ts",
+    golden = "angular/goldens/public-api/platform-browser/errors.md",
+)
+
 filegroup(
     name = "files_for_docgen",
     srcs = glob([

packages/platform-browser/src/errors.ts

@@ -0,0 +1,16 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/**
+ * The list of error codes used in runtime code of the `platform-browser` package.
+ * Reserved error code range: 5000-5500.
+ */
+export const enum RuntimeErrorCode {
+  // Hydration Errors
+  UNSUPPORTED_ZONEJS_INSTANCE = -5000,
+}

packages/platform-browser/src/hydration.ts

@@ -7,7 +7,9 @@
  */
 
 import {ɵwithHttpTransferCache as withHttpTransferCache} from '@angular/common/http';
-import {EnvironmentProviders, makeEnvironmentProviders, Provider, ɵwithDomHydration as withDomHydration} from '@angular/core';
+import {ENVIRONMENT_INITIALIZER, EnvironmentProviders, inject, makeEnvironmentProviders, NgZone, Provider, ɵConsole as Console, ɵformatRuntimeError as formatRuntimeError, ɵwithDomHydration as withDomHydration} from '@angular/core';
+
+import {RuntimeErrorCode} from './errors';
 
 /**
  * The list of features as an enum to uniquely type each `HydrationFeature`.
@@ -91,6 +93,33 @@ export function withNoHttpTransferCache():
   return hydrationFeature(HydrationFeatureKind.NoHttpTransferCache);
 }
 
+/**
+ * Returns an `ENVIRONMENT_INITIALIZER` token setup with a function
+ * that verifies whether compatible ZoneJS was used in an application
+ * and logs a warning in a console if it's not the case.
+ */
+function provideZoneJsCompatibilityDetector(): Provider[] {
+  return [{
+    provide: ENVIRONMENT_INITIALIZER,
+    useValue: () => {
+      const ngZone = inject(NgZone);
+      // Checking `ngZone instanceof NgZone` would be insufficient here,
+      // because custom implementations might use NgZone as a base class.
+      if (ngZone.constructor !== NgZone) {
+        const console = inject(Console);
+        const message = formatRuntimeError(
+            RuntimeErrorCode.UNSUPPORTED_ZONEJS_INSTANCE,
+            'Angular detected that hydration was enabled for an application ' +
+                'that uses a custom or a noop Zone.js implementation. ' +
+                'This is not yet a fully supported configuration.');
+        // tslint:disable-next-line:no-console
+        console.warn(message);
+      }
+    },
+    multi: true,
+  }];
+}
+
 /**
  * Sets up providers necessary to enable hydration functionality for the application.
  * By default, the function enables the recommended set of features for the optimal
@@ -142,6 +171,7 @@ export function provideClientHydration(...features: HydrationFeature<HydrationFe
   }
 
   return makeEnvironmentProviders([
+    (typeof ngDevMode !== 'undefined' && ngDevMode) ? provideZoneJsCompatibilityDetector() : [],
     (featuresKind.has(HydrationFeatureKind.NoDomReuseFeature) ? [] : withDomHydration()),
     (featuresKind.has(HydrationFeatureKind.NoHttpTransferCache) ? [] : withHttpTransferCache()),
     providers,

packages/platform-server/test/hydration_spec.ts

@@ -15,6 +15,7 @@ import {Console} from '@angular/core/src/console';
 import {InitialRenderPendingTasks} from '@angular/core/src/initial_render_pending_tasks';
 import {getComponentDef} from '@angular/core/src/render3/definition';
 import {unescapeTransferStateContent} from '@angular/core/src/transfer_state';
+import {NoopNgZone} from '@angular/core/src/zone/ng_zone';
 import {TestBed} from '@angular/core/testing';
 import {bootstrapApplication, HydrationFeature, HydrationFeatureKind, provideClientHydration, withNoDomReuse} from '@angular/platform-browser';
 import {provideRouter, RouterOutlet, Routes} from '@angular/router';
@@ -587,10 +588,17 @@ describe('platform-server integration', () => {
 
           resetTViewsFor(SimpleComponent, NestedComponent);
 
-          const appRef = await hydrate(html, SimpleComponent);
+          const appRef = await hydrate(html, SimpleComponent, [withDebugConsole()]);
           const compRef = getComponentRef<SimpleComponent>(appRef);
           appRef.tick();
 
+          // Make sure there are no extra logs in case
+          // default NgZone is setup for an application.
+          verifyHasNoLog(
+              appRef,
+              'NG05000: Angular detected that hydration was enabled for an application ' +
+                  'that uses a custom or a noop Zone.js implementation.');
+
           const clientRootNode = compRef.location.nativeElement;
           verifyAllNodesClaimedForHydration(clientRootNode);
           verifyClientAndSSRContentsMatch(ssrContents, clientRootNode);
@@ -3990,6 +3998,78 @@ describe('platform-server integration', () => {
       });
     });
 
+    describe('unsupported Zone.js config', () => {
+      it('should log a warning when a noop zone is used', async () => {
+        @Component({
+          standalone: true,
+          selector: 'app',
+          template: `Hi!`,
+        })
+        class SimpleComponent {
+        }
+
+        const html = await ssr(SimpleComponent);
+        const ssrContents = getAppContents(html);
+
+        expect(ssrContents).toContain('<app ngh');
+
+        resetTViewsFor(SimpleComponent);
+
+        const appRef = await hydrate(html, SimpleComponent, [
+          {provide: NgZone, useValue: new NoopNgZone()},
+          withDebugConsole(),
+        ]);
+        const compRef = getComponentRef<SimpleComponent>(appRef);
+        appRef.tick();
+
+        verifyHasLog(
+            appRef,
+            'NG05000: Angular detected that hydration was enabled for an application ' +
+                'that uses a custom or a noop Zone.js implementation.');
+
+        const clientRootNode = compRef.location.nativeElement;
+
+        verifyAllNodesClaimedForHydration(clientRootNode);
+        verifyClientAndSSRContentsMatch(ssrContents, clientRootNode);
+      });
+
+      it('should log a warning when a custom zone is used', async () => {
+        @Component({
+          standalone: true,
+          selector: 'app',
+          template: `Hi!`,
+        })
+        class SimpleComponent {
+        }
+
+        const html = await ssr(SimpleComponent);
+        const ssrContents = getAppContents(html);
+
+        expect(ssrContents).toContain('<app ngh');
+
+        resetTViewsFor(SimpleComponent);
+
+        class CustomNgZone extends NgZone {}
+
+        const appRef = await hydrate(html, SimpleComponent, [
+          {provide: NgZone, useValue: new CustomNgZone({})},
+          withDebugConsole(),
+        ]);
+        const compRef = getComponentRef<SimpleComponent>(appRef);
+        appRef.tick();
+
+        verifyHasLog(
+            appRef,
+            'NG05000: Angular detected that hydration was enabled for an application ' +
+                'that uses a custom or a noop Zone.js implementation.');
+
+        const clientRootNode = compRef.location.nativeElement;
+
+        verifyAllNodesClaimedForHydration(clientRootNode);
+        verifyClientAndSSRContentsMatch(ssrContents, clientRootNode);
+      });
+    });
+
     describe('error handling', () => {
       it('should handle text node mismatch', async () => {
         @Component({