UNPKG

core-js

Version:
26 lines (23 loc) 842 B
'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; // `WeakMap.prototype.getOrInsertComputed` method // https://github.com/tc39/proposal-upsert $({ target: 'WeakMap', proto: true, real: true, forced: IS_PURE }, { 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; } });