document how and when subprocesses send coverage to nyc & that coverage will be lost for SIGKILLed processes

[jedwards1211]

It seems obvious in retrospect, but I spent hours trying to figure out why I wasn't getting coverage for certain files until I realized it was because I was killing subprocesses that ran those files with SIGKILL. Documentation of this in the README would help others with the same situation figure out why quickly, and I'd be happy to make a PR.

It would be nice to get a high-level overview before digging through the code though. Do subprocesses send coverage to nyc in a process.on('exit', ...) hook, or where? And do they send it via IPC, some kind of sockets, or some other mechanism? If its a coverage channel that can possibly get blocked it would be helpful to document so that people can troubleshoot why files aren't getting covered.

[bcoe]

@jedwards1211 seems like a great idea to document this better, I'll update this thread with some thorough information about how coverage is collected when I have a few more cycles this week.

[JaKXz]

I'm going to move this issue to our website repo for now, thank you for reporting it. Please feel free to make a PR, anyone who is able!