more functional design principles

server/utils/shutdown.js

@@ -5,11 +5,13 @@
 import { SHUTDOWN_TIMEOUT_MS } from './constants.js'
 
 const cleanupFunctions = []
-let isShuttingDown = false
+const shutdownState = {
+  isShuttingDown: false,
+}
 
 export function clearCleanup() {
   cleanupFunctions.length = 0
-  isShuttingDown = false
+  shutdownState.isShuttingDown = false
 }
 
 export function registerCleanup(fn) {
@@ -17,17 +19,25 @@ export function registerCleanup(fn) {
   cleanupFunctions.push(fn)
 }
 
-async function executeCleanup() {
-  if (isShuttingDown) return
-  isShuttingDown = true
-  for (let i = cleanupFunctions.length - 1; i >= 0; i--) {
-    try {
-      await cleanupFunctions[i]()
-    }
-    catch (error) {
-      console.error(`[shutdown] Cleanup function ${i} failed:`, error?.message || String(error))
-    }
+const executeCleanupFunction = async (fn, index) => {
+  try {
+    await fn()
   }
+  catch (error) {
+    console.error(`[shutdown] Cleanup function ${index} failed:`, error?.message || String(error))
+  }
+}
+
+const executeCleanupReverse = async (functions, index = functions.length - 1) => {
+  if (index < 0) return
+  await executeCleanupFunction(functions[index], index)
+  return executeCleanupReverse(functions, index - 1)
+}
+
+async function executeCleanup() {
+  if (shutdownState.isShuttingDown) return
+  shutdownState.isShuttingDown = true
+  await executeCleanupReverse(cleanupFunctions)
 }
 
 export async function graceful(error) {