How to use JSzip external library in angularjs(1.x) application

I’m trying to include typical javascript library(JSZip) in to my angularjs application.

At first i have added included JSZip library in to my application and then added script reference to my index page.

Next i have created a simple object of JSZip in one of my module and trying to create zip. but all of sudden, i am getting compilation error in typescript while building my application in VS2015(visual studio), saying that “Cannot find name JSZip”.

How to load non angular dependency in angular application. i have spent a complete day. i didn’t find any clue.

i have tried multiple ways to get the dependency dynamically and also tried oclazyload to load JSZip dependency ..but not helps.

            var zip = new JSZip(); <=== this is where the problem is..
            zip.file("File1", atob(response.Data));
            zip.file("File2", atob(response.Data));
            zip.generateAsync({ type: "blob" })
                .then(function (content) {
                    // saveAs is from FileSaver.js
                    saveAs(content, "example.zip");
                });

Source: AngularJS