Handle uncaught errors in web server

Author: jahooma

web/instrumentation.ts

@@ -0,0 +1,48 @@
+/**
+ * Next.js Instrumentation
+ *
+ * This file runs once when the server starts and sets up global error handlers
+ * to catch unhandled promise rejections and uncaught exceptions.
+ *
+ * Without these handlers, unhandled errors can crash the Node.js process,
+ * causing Render's proxy to return 502 Bad Gateway errors.
+ */
+
+import { logger } from '@/util/logger'
+
+export function register() {
+  // Handle unhandled promise rejections (async errors that aren't caught)
+  process.on(
+    'unhandledRejection',
+    (reason: unknown, promise: Promise<unknown>) => {
+      logger.error(
+        {
+          reason:
+            reason instanceof Error
+              ? { message: reason.message, stack: reason.stack }
+              : reason,
+          promise: String(promise),
+        },
+        '[CRITICAL] Unhandled Promise Rejection',
+      )
+      // Don't exit - let the process continue to handle other requests
+      // In production, Render will restart if there's a real crash
+    },
+  )
+
+  // Handle uncaught exceptions (sync errors that aren't caught)
+  process.on('uncaughtException', (error: Error, origin: string) => {
+    logger.error(
+      {
+        message: error.message,
+        stack: error.stack,
+        origin,
+      },
+      '[CRITICAL] Uncaught Exception',
+    )
+    // Don't exit - let the process continue to handle other requests
+    // This prevents a single bad request from taking down the entire server
+  })
+
+  logger.info({}, '[Instrumentation] Global error handlers registered')
+}