app js getting merge conflict when merging branch with master (laravel+vue)

Ignore compiled files in your .gitignore there's no reason to push them to your repository unless you don't have node in your server

.gitignore:

/public/js/app.js

Then run

npm install
npm run prod

In your server when you're ready to deploy

Steps to correct

rm public/js/app.js
echo "/public/js/app.js" >> .gitignore
git commit -m "ignore compiled asset"
git push
npm run watch

I usually ignore all compiled assets in public directory

/public/js/*
/public/css/*
/public/fonts

Because it's cleaner and faster to push (since the compiled assets are huge in size +1MB) to have all dependencies in node_modules and write Javascript as ES6 modules in resources/js or formerly resources/assets/js and same for SASS and CSS