How to test received data equals content of json file - Angular 2+

How would one test the received response data from a function equals the contents of a .json file?

For example: I have a function that will fill in some json fields with the values passed to it, and I am wanting to test that this of course works correctly.

What I am thinking...

var firstName: string = 'Jim';
var lastName: string = 'Ross';
var jsonDataMaker: any = service.jsonifyData(firstName, lastName);

const expectedJson = require('./expectedJson.json');

expect(jsonDataMaker).toBe(expectedJson);

Any pointers would be great :-)