PNP.js is not working in Internet Explorer. Am not using SPFx. Custom SharePoint page

Question

I am doing CRUD operation using pnp.js in SharePoint site through custom page. I am able to perform all the actions in EDGE and Chrome browser.

But when I try to do the same in IE browser its not working.

Getting the error as 401.

I received Request header:

Accept: image/gif, image/jpeg, image/pjpeg, application/x-ms-application, application/xaml+xml, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*Accept-Encoding: gzip, deflateAccept-Language: en-USAuthorization: NTLM TlRMTVNTUAABAAAAB4IIogAAAAAAAAAAAAAAAAAAAAAKAO5CAAAADw==Connection: Keep-AliveCookie: WSS_FullScreenMode=falseHost: portaldev.ibx.comIf-Modified-Since: Mon, 13 May 2019 12:09:39 GMTUser-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 10.0; WOW64; Trident/7.0; .NET4.0C; .NET4.0E; .NET CLR 2.0.50727; .NET CLR 3.0.30729; .NET CLR 3.5.30729; InfoPath.3; Zoom 3.6.0) 

Response header:

Content-Length: 0
Date: Mon, 13 May 2019 12:13:30 GMT
MicrosoftSharePointTeamServices: 16.0.0.4822
request-id: 9934dc9e-a935-0049-b7d0-2c747ec5a0ba
Server: Microsoft-IIS/10.0
SPIisLatency: 0
SPRequestDuration: 1
SPRequestGuid: 9934dc9e-a935-0049-b7d0-2c747ec5a0ba
WWW-Authenticate: NTLM TlRMTVNTUAACAAAAEAAQADgAAAAFgomiUcK1cn/yL0oAAAAAAAAAAIoAigBIAAAACgA5OAAAAA9MAEEATgBHAFIATwBVAFAAAgAQAEwAQQBOAEcAUgBPAFUAUAABABAAVwBTAFMAUABMAE4AMAAxAAQADgBpAGIAeAAuAGMAbwBtAAMAIABXAFMAUwBQAEwATgAwADEALgBpAGIAeAAuAGMAbwBtAAUAGABhAGQAZgBvAHIAZQBzAHQALgBjAG8AbQAHAAgAGR2VR4UJ1QEAAAAA
X-Content-Type-Options: nosniff
X-FRAME-OPTIONS: SAMEORIGIN
X-MS-InvokeApp: 1; RequireReadOnly
X-Powered-By: ASP.NET

Answer 1

Internet Explorer does not implement some of the ECMAScipt 6 types used in PnP.js. Because of this you need to use a couple ployfill libraries that implement the missing types. There are a few options on which polyfill libraries you can use, I use fetch and es6-promise.

Adding the following script elements to your page should get things working in Internet Explorer.

<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/fetch/2.0.3/fetch.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/es6-promise/4.1.1/es6-promise.auto.js"></script>