Use a specific error code (99) for inactivity shutdowns

Shouldn't matter much, but this might enable us to debug this better if
it starts happening spuriously in future.

Author: pimterry

src/api/api-server.ts

@@ -122,7 +122,7 @@ export class HttpToolkitServerApi extends events.EventEmitter {
             httpClient,
             {
                 onTriggerUpdate: () => this.emit('update-requested'),
-                onTriggerShutdown: () => shutdown('API call')
+                onTriggerShutdown: () => shutdown(0, 'API call')
             }
         )
 

src/index.ts

@@ -138,7 +138,9 @@ function manageBackgroundServices(
             }
 
             shutdownTimer = setTimeout(() => {
-                if (activeSessions === 0) shutdown('10 minutes inactive');
+                if (activeSessions === 0) {
+                    shutdown(99, '10 minutes inactive');
+                }
             }, 1000 * 60 * 10).unref();
         }
     });

src/shutdown.ts

@@ -5,15 +5,15 @@ type ShutdownHandler = () => Promise<unknown>;
 const shutdownHandlers: Array<ShutdownHandler> = [];
 
 export function registerShutdownHandler() {
-    process.on('SIGTERM', () => shutdown('SIGTERM'));
-    process.on('SIGINT', () => shutdown('SIGINT'));
+    process.on('SIGTERM', () => shutdown(0, 'SIGTERM'));
+    process.on('SIGINT', () => shutdown(0, 'SIGINT'));
 }
 
 export function addShutdownHandler(handler: ShutdownHandler) {
     shutdownHandlers.push(handler);
 }
 
-export async function shutdown(cause: string) {
+export async function shutdown(code: number, cause: string) {
     console.log(`Shutting down after ${cause}...`);
 
     const shutdownPromises = Promise.all(shutdownHandlers.map(
@@ -31,6 +31,6 @@ export async function shutdown(cause: string) {
         delay(2000) // After 2 seconds, we just close anyway, we're done.
     ]);
 
-    process.exit(0);
+    process.exit(code);
 }