Name of main file in packages.json

If I change the index.js to server .js at first after creating the project will it break anything ? does it safe?

In general? There is nothing wrong with that. index is a common name to use, but server gets used too. That line in the package.json file tells the package what to use as an entry point.

Is it a problem in the FCC projects? I don’t know. I don’t know if the test is digging in and looking at the specific files or if it is just loading the package so the package.json file will tell it where to look. I don’t know, but I’m guessing it is the latter, that it’s OK. But it should be easy to test. Just make the change and see if it still works. If it doesn’t, change it back.

But it looks like you are doing your own thing. It shouldn’t be a problem.