A handler for Node process ending. Good for clean up. By default on Ctrl+C, process.exit() and uncaught exceptions.

onProcessExit.js

/**
 * Handles cleanup after basic close events, if the handler returns nothing
 *
 * @param {Function} handler
 * @param {Array<string>} [events=['SIGINT', 'uncaughtException', 'exit']]
 */
export const onProcessExit = (
	handler,
	events = ['SIGINT', 'uncaughtException', 'exit']
) => {
	const closeHandler = type => exitCode => {
		// NB: Should probably log if it equals uncaughtException...
		// Ensure the handler response is a promise, then handle the value returned
		Promise.resolve(handler(type, exitCode)).then(returned => {
			if (shouldExit(returned)) {
				process.exit(exitCode);
			}
		});
	};

	for (const event of events) {
		process.on(event, closeHandler(event));
	}
};

const shouldExit = (handlerResponse, exitType) => {
	// If the handler explicitly returns a bool to say whether to close, then make it exit (unless the eventType is 'exit')
	return typeof handlerResponse === 'boolean'
		? handlerResponse
		: exitType !== 'exit';
};