cleanup-before-nodejs-exits.js

// Register a handler for process.on('exit') and in any other case(SIGINT or unhandled exception) to call process.exit()

process.stdin.resume();//so the program will not close instantly

function exitHandler(options, exitCode) {
    if (options.cleanup) console.log('clean');
    if (exitCode || exitCode === 0) console.log(exitCode);
    if (options.exit) process.exit();
}

//do something when app is closing
process.on('exit', exitHandler.bind(null,{cleanup:true}));

//catches ctrl+c event
process.on('SIGINT', exitHandler.bind(null, {exit:true}));

// catches "kill pid" (for example: nodemon restart)
process.on('SIGUSR1', exitHandler.bind(null, {exit:true}));
process.on('SIGUSR2', exitHandler.bind(null, {exit:true}));

//catches uncaught exceptions
process.on('uncaughtException', exitHandler.bind(null, {exit:true}));

/* This solution has numerous issues. 
(1) It doesn't report signals to parent processes. 
(2) It doesn't convey the exit code to the parent process. 
(3) It doesn't allow for Emacs-like children that ignore Ctrl-C SIGINT. 
(4) It doesn't allow asynchronous cleanup. 
(5) It doesn't coordinate a single stderr message across multiple cleanup handlers. I've written a module that does all this, github.com/jtlapp/node-cleanup, originally based on the cleanup.js solution below, but greatly revised based on feedback. I hope it proves helpful. –
*/