optional-chain-prod-expression.js

Enable keyboard shortcuts

// Copyright 2020 Salesforce.com, Inc. All rights reserved.

// This code is governed by the BSD license found in the LICENSE file.

/*---

esid: prod-OptionalExpression

description: >

  Productions for ?. [Expression]

info: |

  OptionalChain:

    ?.[ Expression ]

features: [optional-chaining]

---*/

const $ = 'x';

const arr = [39, 42];

arr.true = 'prop';

arr[1.1] = 'other prop';

const obj = {

  a: 'hello',

  undefined: 40,

  $: 0,

  NaN: 41,

  null: 42,

  x: 43,

  true: 44

};

assert.sameValue(arr?.[0], 39, '[0]');

assert.sameValue(arr?.[0, 1], 42, '[0, 1]');

assert.sameValue(arr?.[1], 42, '[1]');

assert.sameValue(arr?.[1, 0], 39, '[1, 0]');

assert.sameValue(arr?.[{}, NaN, undefined, 2, 0, 10 / 10], 42, '[{}, NaN, undefined, 2, 0, 10 / 10]');

assert.sameValue(arr?.[true], 'prop', '[true]');

assert.sameValue(arr?.[1.1], 'other prop', '[1.1]');

assert.sameValue(obj?.[undefined], 40, '[undefined]');

assert.sameValue(obj?.[NaN], 41, '[NaN]');

assert.sameValue(obj?.[null], 42, '[null]');

assert.sameValue(obj?.['$'], 0, '["$"]');

assert.sameValue(obj?.[$], 43, '[$]');

assert.sameValue(obj?.[true], 44, '[true]');

reportCompare(0, 0);