.ts file
generateQRCode(data){
let reader = new FileReader();
reader.readAsDataURL(data);
reader.onload = ()=>{
this.QRcode = reader.result;
}
}
.spec.ts file
it('generateQRCode',()=>{
const fakeFile = new File([new Blob(['123'])], 'abc.gif',{type:'image/gif'})
component.generateQRCode(fakeFile)
**expect(component.QRcode).toBeDefined();**
})
how to "component.QRcode" will be defined in the test file