import { blocklistedUsernames } from './constants'; describe('constants', () => { describe('blocklistedUsernames', () => { it('should not contain duplicate values', () => { const uniqueValues = new Set(blocklistedUsernames); expect(blocklistedUsernames.length).toEqual(uniqueValues.size); }); it('should contain all the letters in the latin alphabet', () => { const alphabet = 'abcdefghijklmnopqrstuvwxyz'.split(''); expect(blocklistedUsernames).toEqual(expect.arrayContaining(alphabet)); }); }); }); // Type tests: type BlocklistedUsernames = (typeof blocklistedUsernames)[number]; type HasString = string extends BlocklistedUsernames ? true : false; type Expect = T; // @ts-expect-error - This is intended to fail since we want to ensure that blocklistedUsernames is an array of literals // eslint-disable-next-line @typescript-eslint/no-unused-vars type Test = Expect;