How to implement a Service worker to complete the content before the first page load?

Question

JavaScript

Is it possible to implement the following using the service worker and if so, how:
1) there is a code.js file included in test.html Is it possible to add a few lines of code to code.js before the first page load and code.js execution using the service worker?

2) there is a data.txt file, data from which is used in test.html using js Is it possible to add several lines to data.txt before the first page load using service worker?