fix: don't crash if event name is not a string

src/socket.io/index.js

@@ -120,7 +120,12 @@ async function onMessage(socket, payload) {
 		return winston.warn('[socket.io] Empty method name');
 	}
 
-	const parts = eventName.toString().split('.');
+	if (typeof eventName !== 'string') {
+		const escapedName = validator.escape(String(eventName));
+		return callback({ message: `[[error:invalid-event, ${escapedName}]]` });
+	}
+
+	const parts = eventName.split('.');
 	const namespace = parts[0];
 	const methodToCall = parts.reduce((prev, cur) => {
 		if (prev !== null && prev[cur] && (!prev.hasOwnProperty || prev.hasOwnProperty(cur))) {

test/socket.io.js

@@ -107,6 +107,15 @@ describe('socket.io', () => {
 		});
 	});
 
+	it('should return error for invalid eventName type', (done) => {
+		const eventName = ['topics.loadMoreTags'];
+		io.emit(eventName, function (err) {
+			const eventAsString = String(eventName);
+			assert.strictEqual(err.message, `[[error:invalid-event, ${eventAsString}]]`);
+			done();
+		});
+	});
+
 	it('should get installed themes', (done) => {
 		const themes = ['nodebb-theme-lavender', 'nodebb-theme-persona', 'nodebb-theme-vanilla'];
 		io.emit('admin.themes.getInstalled', (err, data) => {