Prompt before closing window if terminals have running children

[theIDinside]

On Linux the user is prompted with a message box that
child processes are running and if they want to quit
and thus kill them.

Implemented for:

• Linux
• Windows
• MacOS

I might be able to add Windows on this list, but MacOS users; well they're on their own. There is absolutely no way to do this in a cross platform manner. But it works on Linux. As such the pull requests should be accepted and issue updated with information that it is not implemented for the other platforms.

Additional features that could be implemented;

• When user clicks a tab to close; ask the same question as when the window is closed. This requires a lot more insight into the Hyper code base however, since when the user clicks the x (close button) on a tab, the tab immediately disappears from the UI before any "on-close" or "exit" handlers are ran, thus it's on the Electron side, so I suppose some middleware has to be set up, to first direct control back to the "app" code of Hyper, and once handled then send back to Electron to remove it from the UI. Or something like that.

The changes are only made to one file; index.ts. A utility closure called sessionHasRunningChildren checks the Session object's pid, to look in the in-memory drive /proc/.../pid/... to see if Linux has any child info of that pid there and handles it accordingly. It's nowhere near as well designed as this on Windows; instead there we have to jump through a lot of hoops, one of which involves spawning a child process that executes PowerShell and runs some commands - or calling WinAPIs through FFI directly, which in and of itself is very unstable. Poor design, but what else is new on Windows?

I commented in the issue thread here some questions, but I get that this feature isn't exactly at the top of the list.

Also, if and when the PR gets accepted could you be so kind to tag the PR as "hacktoberfest-accepted"? It would be very nice of you.

If you, @LabhanshAgrawal for instance, have some ideas on how to solve the tab thing, or where I could do what is needed, I'd gladly add that additional (though unrequested by the issue) feature, but filed under a separate issue if you would be so kind.

[LabhanshAgrawal]

Thanks a lot for your contribution
I'm on vacation this week, so will not be able to review just yet. Will get back once I've gone through it.

[LabhanshAgrawal]

Adding the label now, as it'll take time for review.

[theIDinside]

Adding the label now, as it'll take time for review.

Thank you! Much appreciated! I'll try and eek out the Windows version of this before the end of October if I can. I think it could possible involve some FFI though, which means it would have to be built during yarn run dev or something like that, which I am completely inexperienced in how to set up. We'll see if I can manage it!

[Giffen-good]

Hey I could provide the code to run a check for Mac OS. May I checkout your PR and add the condition for MacOS within your sessionHasRunningChildren method?

[PythonCoderAS]

Suggested change

	message: `There is still a process running in a hyper terminal. Closing the terminal will kill it`
	message: `There is still a process running in a hyper terminal. Closing the terminal will kill it.`