Class LegacyControlWithValidators

packages/forms/signals/test/web/interop.spec.ts:183–214

    const legacyErrors = signal<ValidationErrors | null>(null);

    @Component({
      selector: 'legacy-control-with-validators',
      template: `<input [value]="value" (input)="onInput($event.target.value)" />`,
      providers: [
        {provide: NG_VALUE_ACCESSOR, useExisting: LegacyControlWithValidators, multi: true},
        {provide: NG_VALIDATORS, useExisting: LegacyControlWithValidators, multi: true},
      ],
    })
    class LegacyControlWithValidators implements ControlValueAccessor, Validator {
      value = '';

      private onChangeFn?: (value: string) => void;

      writeValue(newValue: string): void {
        this.value = newValue;
      }

      registerOnChange(fn: (value: string) => void): void {
        this.onChangeFn = fn;
      }

      registerOnTouched(fn: () => void): void {}

      validate(control: AbstractControl): ValidationErrors | null {
        return legacyErrors();
      }

      onInput(newValue: string) {
        this.value = newValue;
        this.onChangeFn?.(newValue);
      }
    }

    @Component({
      imports: [LegacyControlWithValidators, FormField],