AddValueToKeyedGroup.js 1.3 KB

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  1. 'use strict';
  2. var $TypeError = require('es-errors/type');
  3. var SameValue = require('./SameValue');
  4. var IsArray = require('../helpers/IsArray');
  5. var every = require('../helpers/every');
  6. var forEach = require('../helpers/forEach');
  7. var hasOwn = require('hasown');
  8. var isKeyedGroup = function (group) {
  9. return hasOwn(group, '[[Key]]')
  10. && hasOwn(group, '[[Elements]]')
  11. && IsArray(group['[[Elements]]']);
  12. };
  13. // https://262.ecma-international.org/15.0/#sec-add-value-to-keyed-group
  14. module.exports = function AddValueToKeyedGroup(groups, key, value) {
  15. if (!IsArray(groups) || (groups.length > 0 && !every(groups, isKeyedGroup))) {
  16. throw new $TypeError('Assertion failed: `groups` must be a List of Records with [[Key]] and [[Elements]]');
  17. }
  18. var matched = 0;
  19. forEach(groups, function (g) { // step 1
  20. if (SameValue(g['[[Key]]'], key)) { // step 2
  21. matched += 1;
  22. if (matched > 1) {
  23. throw new $TypeError('Assertion failed: Exactly one element of groups meets this criterion'); // step 2.a
  24. }
  25. var arr = g['[[Elements]]'];
  26. arr[arr.length] = value; // step 2.b
  27. }
  28. });
  29. if (matched === 0) {
  30. var group = { '[[Key]]': key, '[[Elements]]': [value] }; // step 2
  31. // eslint-disable-next-line no-param-reassign
  32. groups[groups.length] = group; // step 3
  33. }
  34. };