webpack - How to append custom code to the generated service worker file -

i'm using webpack , swprecache. swprecache generates service-worker.js file me , want append custom code generated file.

i created webpack plugin appends babel transformed code service-worker.js file, so:

swprecache.write(filepath, options, (function(err) {    // if want append additional file.   if (options.appendfile) {     var sync = fs.readfile(options.appendfile, (error, code) => {       if (error) {         throw error;       }       let transformed = babel.transform(code, options.babelconfig || {});       fs.appendfile(filepath, transformed.code);     });   }    callback(err); })); 

this not include code make require() work in file i'm appending. believe need use webpack generate service-worker.js file i'm unsure how that, possibly via custom entry point?

to include custom script generated serviceworker, recommended way use importscripts option in sw-precache config.you can find more details here.