1 files changed, 46 insertions, 0 deletions
diff --git a/node_modules/exit-hook/index.js b/node_modules/exit-hook/index.js
new file mode 100644
index 0000000..fc309b0
--- /dev/null
+++ b/node_modules/exit-hook/index.js
@@ -0,0 +1,46 @@
+'use strict';
+
+const callbacks = new Set();
+let isCalled = false;
+let isRegistered = false;
+
+function exit(exit, signal) {
+	if (isCalled) {
+		return;
+	}
+
+	isCalled = true;
+
+	for (const callback of callbacks) {
+		callback();
+	}
+
+	if (exit === true) {
+		process.exit(128 + signal); // eslint-disable-line unicorn/no-process-exit
+	}
+}
+
+module.exports = callback => {
+	callbacks.add(callback);
+
+	if (!isRegistered) {
+		isRegistered = true;
+
+		process.once('exit', exit);
+		process.once('SIGINT', exit.bind(null, true, 2));
+		process.once('SIGTERM', exit.bind(null, true, 15));
+
+		// PM2 Cluster shutdown message. Caught to support async handlers with pm2, needed because
+		// explicitly calling process.exit() doesn't trigger the beforeExit event, and the exit
+		// event cannot support async handlers, since the event loop is never called after it.
+		process.on('message', message => {
+			if (message === 'shutdown') {
+				exit(true, -128);
+			}
+		});
+	}
+
+	return () => {
+		callbacks.delete(callback);
+	};
+};