feat: Provide optional shouldHandleError option for node errorHandler (#2146)

* feat: Provide optional shouldHandleError option for node errorHandler

* Update packages/node/src/handlers.ts

Co-Authored-By: Daniel Griesser <daniel.griesser.86@gmail.com>

Author: kamilogorek

packages/browser/src/integrations/trycatch.ts

@@ -70,6 +70,7 @@ export class TryCatch implements Integration {
         options?: boolean | AddEventListenerOptions,
       ): (eventName: string, fn: EventListenerObject, capture?: boolean, secure?: boolean) => void {
         try {
+          // tslint:disable-next-line:no-unbound-method strict-type-predicates
           if (typeof fn.handleEvent === 'function') {
             fn.handleEvent = wrap(fn.handleEvent.bind(fn), {
               mechanism: {

packages/node/src/handlers.ts

@@ -272,11 +272,23 @@ function getStatusCodeFromResponse(error: MiddlewareError): number {
   return statusCode ? parseInt(statusCode as string, 10) : 500;
 }
 
+/** Returns true if response code is internal server error */
+function defaultShouldHandleError(error: MiddlewareError): boolean {
+  const status = getStatusCodeFromResponse(error);
+  return status >= 500;
+}
+
 /**
  * Express compatible error handler.
  * @see Exposed as `Handlers.errorHandler`
  */
-export function errorHandler(): (
+export function errorHandler(options?: {
+  /**
+   * Callback method deciding whether error should be captured and sent to Sentry
+   * @param error Captured middleware error
+   */
+  shouldHandleError?(error: MiddlewareError): boolean;
+}): (
   error: MiddlewareError,
   req: http.IncomingMessage,
   res: http.ServerResponse,
@@ -288,20 +300,23 @@ export function errorHandler(): (
     _res: http.ServerResponse,
     next: (error: MiddlewareError) => void,
   ): void {
-    const status = getStatusCodeFromResponse(error);
-    if (status < 500) {
-      next(error);
+    const shouldHandleError = (options && options.shouldHandleError) || defaultShouldHandleError;
+
+    if (shouldHandleError(error)) {
+      withScope(scope => {
+        if (_req.headers && isString(_req.headers['sentry-trace'])) {
+          const span = Span.fromTraceparent(_req.headers['sentry-trace'] as string);
+          scope.setSpan(span);
+        }
+        const eventId = captureException(error);
+        (_res as any).sentry = eventId;
+        next(error);
+      });
+
       return;
     }
-    withScope(scope => {
-      if (_req.headers && isString(_req.headers['sentry-trace'])) {
-        const span = Span.fromTraceparent(_req.headers['sentry-trace'] as string);
-        scope.setSpan(span);
-      }
-      const eventId = captureException(error);
-      (_res as any).sentry = eventId;
-      next(error);
-    });
+
+    next(error);
   };
 }