LWC - catch block is always getting executed in loadscript LWC

Question

My static resource

Trying to load this script using loadscript. Below is my code...

    import { api,track,LightningElement } from 'lwc';
        import {
            loadScript
        } from 'lightning/platformResourceLoader';
        import instascan from '@salesforce/resourceUrl/instascan';


    export default class QRCodeScanner extends LightningElement {
        @track instascanInitialized = false;

        renderedCallback() {
                if(this.instascanInitialized){
                    return;
                }
                this.instascanInitialized = true;
                loadScript(this, instascan)
                    .then(() => { 
                        console.log('hii then'+then);
                    })
                    .catch(error => {
                        console.log('hii error' +error);
                    });
            }
  }

Always getting the same thing in the console

According to the console the catch block is getting executed. But in the network tab I see the static resource is been initialized properly!

Please let me know why am I getting this error even if the static resource is been loaded and how do I resolve this?

Answer 1

Its not the problem with your implementation.

Instascan is not compliant with Locker service. A quick read from this article - Is there any way to validate a third party JavaScript library against Lightning LockerService?, and checking instascan library, below will be observations:

• It has new function
• It has eval() usage
• It does not have global use strict

Comparatively JQuery is locker service compliant and will have no problem loading in LWC.