core-js/modules/esnext.weak-map.get-or-insert-computed.js

Standard library

'use strict';
var $ = require('../internals/export');
var aCallable = require('../internals/a-callable');
var aWeakMap = require('../internals/a-weak-map');
var aWeakKey = require('../internals/a-weak-key');
var WeakMapHelpers = require('../internals/weak-map-helpers');
var IS_PURE = require('../internals/is-pure');

var get = WeakMapHelpers.get;
var has = WeakMapHelpers.has;
var set = WeakMapHelpers.set;

var FORCED = IS_PURE || !function () {
  try {
    // eslint-disable-next-line es/no-weak-map, no-throw-literal -- testing
    if (WeakMap.prototype.getOrInsertComputed) new WeakMap().getOrInsertComputed(1, function () { throw 1; });
  } catch (error) {
    // FF144 Nightly - Beta 3 bug
    // https://bugzilla.mozilla.org/show_bug.cgi?id=1988369
    return error instanceof TypeError;
  }
}();

// `WeakMap.prototype.getOrInsertComputed` method
// https://github.com/tc39/proposal-upsert
$({ target: 'WeakMap', proto: true, real: true, forced: FORCED }, {
  getOrInsertComputed: function getOrInsertComputed(key, callbackfn) {
    aWeakMap(this);
    aWeakKey(key);
    aCallable(callbackfn);
    if (has(this, key)) return get(this, key);
    var value = callbackfn(key);
    set(this, key, value);
    return value;
  }
});