bug(CORE): HasErrorState interface has incorrect types

[Akxe]

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

The HasErrorState interface used in mixinErrorState do require _parentFormGroup and _parentForm to be non-null. But the _ErrorStateTracker that is using it does not care.

Reproduction

StackBlitz link: https://stackblitz.com/edit/components-issue-ovhttn?file=src%2Fapp%2Fexample-component.ts
Steps to reproduce:

1. Build
2. See error

Expected Behavior

The HasErrorState interface should mimic type requirements from _ErrorStateTracker and therefore work.

Actual Behavior

Error that _parentFormGroup and _parentForm cannot be null.

Environment

Angular CLI: 17.2.0
Node: 20.10.0
Package Manager: npm 10.2.5
OS: win32 x64

Angular: 17.2.1
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

Package Version

@angular-devkit/architect 0.1702.1
@angular-devkit/core 17.2.1
@angular-devkit/schematics 17.2.0
@angular/cdk 17.2.0
@angular/cli 17.2.0
@angular/material 17.2.0
@schematics/angular 17.0.3
rxjs 7.8.1
typescript 5.3.3
zone.js 0.14.3

[Akxe]

Along this. It would be nice if a complete example of how to create a custom form control element compatible with mat-form-field would look like. A simple extendable class would be perfect for most users.

[angular-automatic-lock-bot]

This issue has been automatically locked due to inactivity.
Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}