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