How to implement MD_DATE_FORMATS for datepicker?

I'm trying to implement my own date format for shiny new datepicker from material2. According to documentation i have to provide my version of MD_DATE_FORMATS:

providers: [
  {provide: DateAdapter, useValue: NativeDateAdapter },
  {provide: MD_DATE_FORMATS, useValue: MY_DATE_FORMATS },
],

When I use default implementation:

export const MD_NATIVE_DATE_FORMATS: MdDateFormats = {
  parse: {
    dateInput: null,
  },
  display: {
    dateInput: {year: 'numeric', month: 'numeric', day: 'numeric'},
    monthYearLabel: {year: 'numeric', month: 'short'},
    dateA11yLabel: {year: 'numeric', month: 'long', day: 'numeric'},
    monthYearA11yLabel: {year: 'numeric', month: 'long'},
  }
};

I get an error that date input is null. But what type it really is? Documentation says any.

If i try to put some dummy function there i get error: _dateAdapter.parse is not a function.

function dateInput() {
    return 'ddd';
}
const MY_DATE_FORMATS: MdDateFormats = Object.assign({}, MD_NATIVE_DATE_FORMATS, {parse: dateInput });

How to make it work?