es6Promise是个库而已,不会自动polyfill,该插件可以让es6Promise自动polyfill。
<!-- Automatically provides/replaces `Promise` if missing or broken. -->
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.js"></script>
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.auto.js"></script>
<!-- Minified version of `es6-promise-auto` below. -->
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/es6-promise@4/dist/es6-promise.auto.min.js"></script>
es6-promise.auto会检测Promise是否存在,若存在原生的Promise,则不执行;否则会应用polyfill。
应用:
<script>
window.Promise = 32;
</script>
<script src="https://cdn.bootcss.com/es6-promise/4.1.1/es6-promise.auto.js"></script>
<script>
console.log(Promise);//ƒ Promise$3(resolver) {} ,已被更改
</script>
不应用:
<script>
// window.Promise = 32;
</script>
<script src="https://cdn.bootcss.com/es6-promise/4.1.1/es6-promise.auto.js"></script>
<script>
console.log(Promise); // ƒ Promise() { [native code] }, 未被更改
</script>
GitHub 地址 : https://github.com/stefanpenner/es6-promise?utm_source=cdnjs&utm_medium=cdnjs_link&utm_campaign=cdnjs_library