[Regression] Initializing an Angular form in a signalStore via a state factory no longer works in @ngrx/signals 19

[g-drouard]

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

signals

Minimal reproduction of the bug/regression with instructions

1. Create a new Angular 19 app with ng new xxx for example
2. Install ngrx/signals 19.0.0 with ng add @ngrx/signals@latest for example
3. Add a new signal store with a FormControl in the withState via a state factory () => state instead of a standard state
4. Run app with npm start and go to http://localhost:4200/ with a browser (Chrome for example)

app.component.ts

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrl: './app.component.scss',
  providers: [TestStore]
})
export class AppComponent {
  store = inject(TestStore);
}

test.store.ts

Works with @ngrx/signals 18.1.1 and 19.0.0 :

import { signalStore, withState } from '@ngrx/signals';
import { FormControl } from '@angular/forms';

export const TestStore = signalStore(withState({ formControl: new FormControl('test') }))

Works with @ngrx/signals 18.1.1 but does not work with 19.0.0 :

import { signalStore, withState } from '@ngrx/signals';
import { FormControl } from '@angular/forms';

export const TestStore = signalStore(withState(() => ({ formControl: new FormControl('test') })))

Runtime error call stack :

TypeError: Cannot assign to read only property 'microTask' of object '[object Object]'
    at _ZoneDelegate._updateTaskCount (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:432:38)
    at ZoneImpl._updateTaskCount (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:264:34)
    at ZoneImpl.runTask (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:177:30)
    at drainMicroTaskQueue (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:581:35)
TypeError: Cannot assign to read only property 'microTask' of object '[object Object]'
    at _ZoneDelegate._updateTaskCount (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:432:38)
    at ZoneImpl._updateTaskCount (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:264:34)
    at ZoneImpl.runTask (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:177:30)
    at drainMicroTaskQueue (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:581:35)
Error: microTask 'Promise.then': can not transition to 'running', expecting state 'scheduled', was 'scheduling'.
    at ZoneTask._transitionTo (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:510:23)
    at ZoneImpl.runTask (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:150:38)
    at drainMicroTaskQueue (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:581:35)
C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:432
            const next = (counts[type] = prev + count);
                                     ^


TypeError: Cannot assign to read only property 'microTask' of object '[object Object]'
    at _ZoneDelegate._updateTaskCount (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:432:38)
    at ZoneImpl._updateTaskCount (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:264:34)
    at ZoneImpl.scheduleTask (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:217:22)
    at ZoneImpl.scheduleMicroTask (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:225:25)
    at eval (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:958:33)
    at process.proto.<computed> (C:\Sites\ng-19-sandbox\node_modules\zone.js\fesm2015\zone-node.js:913:24)
    at maybeReadMore (node:internal/streams/readable:860:13)
    at addChunk (node:internal/streams/readable:578:3)
    at readableAddChunkPushByteMode (node:internal/streams/readable:512:3)
    at Readable.push (node:internal/streams/readable:392:5)

Node.js v22.11.0

Expected behavior

Same behavior as version 18.1.1

Versions of NgRx, Angular, Node, affected browser(s) and operating system(s)

Angular : 19.0.x
@ngrx/signals : 19.0.0
Node : 22.11.0

Other information

No response

I would be willing to submit a PR to fix this issue

• Yes
• No

[rainerhahnekamp]

@g-drouard that looks very similar to #4650

You should not put objects in the state that are getting mutated by the framework.

That being said, we're looking into options to allow you disable the freezing: #4645

I'm closing this one because it already handled in #4645, okay?