import isString from '../../utils/isString'; describe('isString', () => { it('should return true when value is a string', () => { expect(isString('')).toBeTruthy(); expect(isString('foobar')).toBeTruthy(); }); it('should return false when value is not a string', () => { expect(isString(null)).toBeFalsy(); expect(isString(undefined)).toBeFalsy(); expect(isString(-1)).toBeFalsy(); expect(isString(0)).toBeFalsy(); expect(isString(1)).toBeFalsy(); expect(isString({})).toBeFalsy(); expect(isString([])).toBeFalsy(); expect(isString(new String('test'))).toBeFalsy(); expect(isString(() => null)).toBeFalsy(); }); });