Why does TS stops me from defining my own type when using alias? "TS2769: No overload matches this call"

[Vadorequest]

I'm trying to use an alias, as mentioned in https://docs.cypress.io/guides/core-concepts/variables-and-aliases.html#Sharing-Context

The issue is with this part of the code, I must use // @ts-ignore because otherwise I get the following TS error TS2769: No overload matches this call.   The last overload gave the following error.     Argument of type '(customer: Customer) => void' is not assignable to parameter of type '(this: ObjectLike, currentSubject: JQuery<HTMLElement>) => void'.:

  it(`should have "window.${CYPRESS_WINDOW_NS}.customer.ref" defined`, () => {
    // @ts-ignore
    cy.get('@customer').then((customer: Customer) => {
      assert.isDefined(customer.ref);
    });
  });

The test runs fine regardless of the TS error. Is it a typing issue or should I declare my type differently?

Full code:

import { Customer } from '../../../../src/types/data/Customer';
import { CYPRESS_WINDOW_NS } from '../../../../src/utils/testing/cypress';

describe('Sanity checks > Browser data', () => {
  /*
  * Visits the home page before any test
  */
  beforeEach(() => {
    cy.visit('/en');
    cy.window().then((window) => {
      const {
        customer,
        dataset,
      } = window[CYPRESS_WINDOW_NS];

      // Use aliases to make our variables reusable across tests - See https://docs.cypress.io/guides/core-concepts/variables-and-aliases.html#Sharing-Context
      cy.wrap(window[CYPRESS_WINDOW_NS]).as('__CYPRESS_DATA__');
      cy.wrap(customer).as('customer');
      cy.wrap(dataset).as('dataset');
    });

  });

  it(`should have "window.${CYPRESS_WINDOW_NS}" defined`, () => {
    assert.isDefined(cy.get('@__CYPRESS_DATA__'));
    assert.isDefined(cy.get('@customer'));
    assert.isDefined(cy.get('@dataset'));
  });

  it(`should have "window.${CYPRESS_WINDOW_NS}.customer.ref" defined`, () => {
    // @ts-ignore
    cy.get('@customer').then((customer: Customer) => {
      assert.isDefined(customer.ref);
    });
  });
});

[Vadorequest]

Answer:

    cy.get<Customer>('@customer').then((customer: Customer) => {
      assert.isDefined(customer.ref);
    });

get allows a dynamic type. See:

get<E extends Node = HTMLElement>(selector: string, options?: Partial<Loggable & Timeoutable & Withinable & Shadow>): Chainable<JQuery<E>>