import lodashStable from 'lodash'; import { falsey, args, slice, symbol, realm } from './utils'; import isString from '../src/isString'; describe('isString', () => { it('should return `true` for strings', () => { expect(isString('a')).toBe(true); expect(isString(Object('a'))).toBe(true); }); it('should return `false` for non-strings', () => { const expected = lodashStable.map(falsey, (value) => value === ''); const actual = lodashStable.map(falsey, (value, index) => index ? isString(value) : isString(), ); expect(actual).toEqual(expected); expect(isString(args)).toBe(false); expect(isString([1, 2, 3])).toBe(false); expect(isString(true)).toBe(false); expect(isString(new Date())).toBe(false); expect(isString(new Error())).toBe(false); expect(isString(slice)).toBe(false); expect(isString({ 0: 1, length: 1 })).toBe(false); expect(isString(1)).toBe(false); expect(isString(/x/)).toBe(false); expect(isString(symbol)).toBe(false); }); it('should work with strings from another realm', () => { if (realm.string) { expect(isString(realm.string)).toBe(true); } }); });