const {pluralize} = require('./_30s.js'); test('pluralize is a Function', () => { expect(pluralize).toBeInstanceOf(Function); }); test('Produces the plural of the word', () => { expect(pluralize(0, 'apple')).toBe('apples'); }); test('Produces the singular of the word', () => { expect(pluralize(1, 'apple')).toBe('apple'); }); test('Produces the plural of the word', () => { expect(pluralize(2, 'apple')).toBe('apples'); }); test('Produces the defined plural of the word', () => { expect(pluralize(2, 'person', 'people')).toBe('people'); }); test('Produces the defined plural of the word', () => { expect(pluralize(1, 'person', 'people')).toBe('person'); }); const PLURALS = { person: 'people', radius: 'radii' }; const autoPluralize = pluralize(PLURALS); test('Works with a dictionary', () => { expect(autoPluralize(2, 'person')).toBe('people'); });