fetch HttpClient + signals is not triggering cdr

[zip-fa]

Which @angular/* package(s) are the source of the bug?

common

Is this a regression?

Yes

Description

HttpClient withFetch() will not trigger CDR with nested queries coming from switchMap

Please provide a link to a minimal reproduction of the bug

https://stackblitz.com/edit/angular-at-wvr9ue?file=src%2Fmain.ts

Please provide the exception or error you saw

No response

Please provide the environment you discovered this bug in (run ng version)

Angular: 17.0.0-next.7
... animations, cli, common, compiler, compiler-cli, core, forms
... localize, platform-browser, platform-browser-dynamic, router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1700.0-next.7
@angular-devkit/build-angular   17.0.0-next.7
@angular-devkit/core            17.0.0-next.7
@angular-devkit/schematics      17.0.0-next.7
@angular/cdk                    17.0.0-next.5
@angular/material               17.0.0-next.6
@schematics/angular             17.0.0-next.7
rxjs                            7.4.0
typescript                      5.2.2
zone.js                         0.13.0

Anything else?

No response

[JeanMeche]

Well, thank you for reporting that,

this.client
  .get('https://random-data-api.com/api/beer/random_beer')
  .subscribe(() => {
    NgZone.assertInAngularZone();
  });

Fails miserably when using the FetchBackend

Edit: This bug only happens with the browser-esbuild builder.

[surajy93]

import { ChangeDetectorRef } from '@angular/core';

// Inside your component constructor or method
constructor(private cd: ChangeDetectorRef) { }

// Inside your HTTP request subscription or switchMap
this.http.get('your-url').subscribe((data) => {
// Process data
// Trigger change detection
this.cd.detectChanges();
});

[JeanMeche]

cc @alan-agius4 If you have any idea why the builder changes the behaviour we can observe here.

Edit: it's getting weirder every time i try to look into it, it seems to be caching related in serve mode.

• cache=true + esbuild + serve = KO
• cache=true + esbuild + build = OK
• cache=false + esbuild + serve = OK
• cache=true + webpack + serve = OK

[alan-agius4]

Yeah, I know what is going on. I'll open a PR later today.