jest-hooks.test.js

/* testing/src/__tests__/helpers/index.test.js */

import { /* ... */ , setTraysForId, getTraysForId } from '../../helpers';

describe('Trays', () => {
  beforeEach(() => {
    window.localStorage.clear();
  });

  test('are stored locally on setting them via the id', () => {
    const id = 123;
    const trays = ['movies', 'cartoons', 'true crime'];
    const stringifiedTrays = JSON.stringify(trays);

    setTraysForId(id, trays);

    expect(window.localStorage.getItem(`${id}`)).toEqual(stringifiedTrays);
  });

  test('are fetched locally on searching for them via the id', () => {
    const id = 123;
    const trays = ['movies', 'cartoons', 'true crime'];
    const stringifiedTrays = JSON.stringify(trays);
    setTraysForId(id, trays);
    
    const actualTrays = getTraysForId(id);

    expect(actualTrays).toEqual(trays);
  });
});