bug(mat-datepicker): date parse errors are not propagated to Signal Forms #33952

Is this a regression?

No

Description

The datepicker input provides a matDatepickerParse validation error when the user enters text that cannot be parsed as a date.

This error is available when using Reactive Forms, but when using Signal Forms, the error does not reach the errors signal of the field tree. The value of the form field stays as null.

Reproduction

StackBlitz link: https://stackblitz.com/edit/stackblitz-starters-d3y2q7gw?file=src%2Fmain.ts,src%2Fmain.ts

Steps to reproduce:

1. Start the application.
2. Enter an invalid date string into the Reactive Forms datepicker.
3. Observe that the control reports a matDatepickerParse error.
4. Enter the same invalid date string into the Signal Forms datepicker.
5. Observe that the Signal Forms field does not report the corresponding parse error in field().errors().

Expected Behavior

I would expect the date parse errors to also be available to the Signal Form.

If I understand correctly, this seems to be in line with the direction of the Angular Signal Forms API, for example with https://angular.dev/api/forms/signals/transformedValue to report parse errors in custom controls.

Actual Behavior

The date parse errors are not available to the Signal Form. Since the form value remains as null for invalid values, distinguishing between an empty form and invalid input is not possible in the schema.

Environment

• Angular: 22.2.2
• CDK/Material: 22.2.2
• Browser(s): Chrome, Firefox, Safari
• Operating System (e.g. Windows, macOS, Ubuntu): macOS