fix: make writeFile sync on finish

[alfonsograziano]

I'm investigating on this issue on the node-clinic repo.

Basically, when the script which is profiled by clinic.js calls process.exit(0), the profile file is not written. The file is created but internally it is empty. Changing the writeFile to its synchronous version is fixing this issue locally

[marco-ippolito]

I think the issue might be caused by writeFile inside a setInterval on the same destination without waiting for the callback.
Quoting Node.js documentation:

It is unsafe to use fs.writeFile() multiple times on the same file without waiting for the callback. For this scenario, fs.createWriteStream() is recommended.

I think it's accettable to use writeFileSync or createWriteStream.

[RafaelGSS]

can you add a test?

[alfonsograziano]

@RafaelGSS I'd love to, but unfortunately the tests are failing for me locally (with and without this change).
At the same time, I already created a test for this case in the clinic-library. Not sure if that's enough :)

[RafaelGSS]

@RafaelGSS I'd love to, but unfortunately the tests are failing for me locally (with and without this change). At the same time, I already created a test for this case in the clinic-library. Not sure if that's enough :)

Did you try using v18?

[RafaelGSS]

You can also cherry pick your commit in the last github tag which is supposed to be passing in CI