fix: do not send error when error code is fine

src/invoker.ts

@@ -28,7 +28,7 @@ import * as http from 'http';
 import * as onFinished from 'on-finished';
 
 import {FUNCTION_STATUS_HEADER_FIELD} from './types';
-import {logAndSendError} from './logger';
+import {sendCrashResponse} from './logger';
 import {isBinaryCloudEvent, getBinaryCloudEventContext} from './cloudevents';
 import {
   HttpFunction,
@@ -111,7 +111,7 @@ function makeHttpHandler(execute: HttpFunction): express.RequestHandler {
         console.error(`Exception from a finished function: ${err}`);
       } else {
         res.locals.functionExecutionFinished = true;
-        logAndSendError(err, res);
+        sendCrashResponse({err, res});
       }
     });
     d.run(() => {
@@ -305,16 +305,20 @@ export class ErrorHandler {
   register() {
     process.on('uncaughtException', err => {
       console.error('Uncaught exception');
-      logAndSendError(err, latestRes, killInstance);
+      sendCrashResponse({err, res: latestRes, callback: killInstance});
     });
 
     process.on('unhandledRejection', err => {
       console.error('Unhandled rejection');
-      logAndSendError(err, latestRes, killInstance);
+      sendCrashResponse({err, res: latestRes, callback: killInstance});
     });
 
     process.on('exit', code => {
-      logAndSendError(new Error(`Process exited with code ${code}`), latestRes);
+      sendCrashResponse({
+        err: new Error(`Process exited with code ${code}`),
+        res: latestRes,
+        silent: code === 0,
+      });
     });
 
     ['SIGINT', 'SIGTERM'].forEach(signal => {

src/logger.ts

@@ -22,13 +22,21 @@ import {FUNCTION_STATUS_HEADER_FIELD} from './types';
  * @param res Express response object.
  * @param callback A function to be called synchronously.
  */
-export function logAndSendError(
+export function sendCrashResponse({
+  err,
+  res,
+  callback,
+  silent = false,
+}: {
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  err: Error | any,
-  res: express.Response | null,
-  callback?: Function
-) {
-  console.error(err.stack || err);
+  err: Error | any;
+  res: express.Response | null;
+  callback?: Function;
+  silent?: boolean;
+}) {
+  if (!silent) {
+    console.error(err.stack || err);
+  }
 
   // If user function has already sent response headers, the response with
   // error message cannot be sent. This check is done inside the callback,