Function cleanUpControl

packages/forms/src/directives/shared.ts:122–148

(
  control: FormControl | null,
  dir: NgControl,
  validateControlPresenceOnChange: boolean = true,
)

 *     to avoid potentially breaking changes caused by better control cleanup introduced in #39235.
 */
export function cleanUpControl(
  control: FormControl | null,
  dir: NgControl,
  validateControlPresenceOnChange: boolean = true,
): void {
  const noop = () => {
    if (validateControlPresenceOnChange && (typeof ngDevMode === 'undefined' || ngDevMode)) {
      _noControlError(dir);
    }
  };

  // The `valueAccessor` field is typically defined on FromControl and FormControlName directive
  // instances and there is a logic in `selectValueAccessor` function that throws if it's not the
  // case. We still check the presence of `valueAccessor` before invoking its methods to make sure
  // that cleanup works correctly if app code or tests are setup to ignore the error thrown from
  // `selectValueAccessor`. See https://github.com/angular/angular/issues/40521.

  dir?.valueAccessor?.registerOnChange(noop);
  dir?.valueAccessor?.registerOnTouched(noop);

  cleanUpValidators(control, dir);

  if (control) {
    dir._invokeOnDestroyCallbacks();
    control._registerOnCollectionChange(() => {});
  }
}

function registerOnValidatorChange<V>(validators: (V | Validator)[], onChange: () => void): void {
  validators.forEach((validator: V | Validator) => {