com.google.javascript.jscomp.js.util.shouldpolyfill.js Maven / Gradle / Ivy
/*
* Copyright 2020 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @fileoverview Helpers to decide whether to trust existing implementations of
* polyfilled methods.
* @suppress {uselessCode} the requires are considered "useless"
*/
'require util/defines';
/**
* @const {boolean} whether Symbol is implemented natively (i.e. is not a
* polyfill)
*/
$jscomp.IS_SYMBOL_NATIVE =
typeof Symbol === 'function' && typeof Symbol('x') === 'symbol';
/**
* Whether code should use built-in versions of ES6 methods when available.
*
* @const {boolean}
*/
$jscomp.TRUST_ES6_POLYFILLS =
!$jscomp.ISOLATE_POLYFILLS || $jscomp.IS_SYMBOL_NATIVE;