fix(cosmic-swingset): straighten out shutdown signals and exit code

packages/cosmic-swingset/src/shutdown.js

@@ -4,33 +4,35 @@ import anylogger from 'anylogger';
 
 const console = anylogger('shutdown');
 
-export const makeFreshShutdown = () => {
+export const makeFreshShutdown = (verbose = true) => {
   const shutdownThunks = new Set();
 
   let shuttingDown = false;
   /** @type {NodeJS.SignalsListener & NodeJS.BeforeExitListener} */
   const shutdown = code => {
     const sig = typeof code === 'string' && code.startsWith('SIG');
     if (sig) {
-      process.exitCode = 99;
+      process.exitCode = 98;
     }
     if (shuttingDown) {
-      process.exit();
+      return;
     }
     shuttingDown = true;
-    console.error('Shutting down cleanly...');
+    // Allow an explicit exit to terminate the process.
+    process.off('beforeExit', shutdown);
+    verbose && console.error(`Shutting down cleanly...`);
     const shutdowners = [...shutdownThunks.keys()];
     shutdownThunks.clear();
     Promise.allSettled([...shutdowners].map(t => Promise.resolve().then(t)))
       .then(statuses => {
         for (const status of statuses) {
           if (status.status === 'rejected') {
-            console.warn(status.reason);
+            verbose && console.warn(status.reason);
           }
         }
-        console.log('Process terminated!');
+        verbose && console.warn('Process terminated!');
       })
-      .catch(error => console.warn('Error shutting down', error))
+      .catch(error => verbose && console.warn('Error shutting down', error))
       .finally(() => {
         process.exit();
       });
@@ -39,7 +41,6 @@ export const makeFreshShutdown = () => {
   // gracefully shut down the thunks on process exit
   process.on('SIGTERM', shutdown);
   process.on('SIGINT', shutdown);
-  process.on('SIGQUIT', shutdown);
   process.on('beforeExit', shutdown);
   process.on('uncaughtException', e => {
     console.error(e);
@@ -57,9 +58,11 @@ export const makeFreshShutdown = () => {
 };
 
 let cachedShutdown = null;
-export const makeCachedShutdown = () => {
+export const makeCachedShutdown = (...args) => {
+  // It's possible our caller has specified different arguments.
+  // Since they control verbosity only, first-one-wins is acceptable.
   if (!cachedShutdown) {
-    cachedShutdown = makeFreshShutdown();
+    cachedShutdown = makeFreshShutdown(...args);
   }
   return cachedShutdown;
 };