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4 years ago
'use strict';
var anObject = require('../internals/an-object');
// `Map.prototype.upsert` method
// https://github.com/thumbsupep/proposal-upsert
module.exports = function upsert(key, updateFn /* , insertFn */) {
var map = anObject(this);
var insertFn = arguments.length > 2 ? arguments[2] : undefined;
var value;
if (typeof updateFn != 'function' && typeof insertFn != 'function') {
throw TypeError('At least one callback required');
}
if (map.has(key)) {
value = map.get(key);
if (typeof updateFn == 'function') {
value = updateFn(value);
map.set(key, value);
}
} else if (typeof insertFn == 'function') {
value = insertFn();
map.set(key, value);
} return value;
};