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node.jstypescriptjestjscurrencynumber-formatting

How to tell Jest that spaces are in fact, spaces?

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:

Screenshot of Jest complaining that the string are not equal even though both are seemingly the same string. Error is on the space in between number and currency produced by the Intl component.

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

Solution

  • You want this test to assert:

    "42,00\xa0€"

    It's not a space (different ascii code / unicode). According to a jest issue about string comparison being incorrect Intl.NumberFormat uses a non-breaking space.

    And as pointed out in a similar question's answer:

    NumberFormat use small non-breaking space (\u202f) for thousand separator and normal non-breaking space beforece currency (\xa0).