Given the code:

import { getLocale } from './locale';

export const euro = (priceData: number): string => {
  const priceFormatter = new Intl.NumberFormat(getLocale(), {
    style: 'currency',
    currency: 'EUR',
  });

  return priceFormatter.format(priceData);
}

export default null;

and the related test:

import { euro } from './currency';

test('euro', () => {
  expect(euro(42)).toBe("42,00 €");
});

Jest says:

Even if I copy-paste the expected result of Jest to my assert, the error is still the same.

So the question is: Why the hell? :-D