const {decapitalize} = require('./_30s.js'); test('decapitalize is a Function', () => { expect(decapitalize).toBeInstanceOf(Function); }); test('Works with default parameter', () => { expect(decapitalize('FooBar')).toBe('fooBar'); }); test('Works with second parameter set to true', () => { expect(decapitalize('FooBar', true)).toBe('fOOBAR'); });