fix(nextjs): Check for invalid tunnel option on server

If the tunnel option will cause an error to be thrown, catch it, and re-throw
with a better error message.


Fixes GH-6381

Author: Naddiseo

packages/nextjs/src/index.server.ts

@@ -79,6 +79,15 @@ export function init(options: NextjsOptions): void {
   const activeDomain = domain.active;
   domain.active = null;
 
+  if (typeof options.tunnel !== 'undefined') {
+    try {
+      new URL(options.tunnel);
+    } catch (error) {
+      __DEBUG_BUILD__ &&
+        logger.error('The tunnel option is not a valid URL. It must be a full URL including the protocol.');
+      throw new Error('The tunnel option is not a valid URL. It must be a full URL including the protocol.');
+    }
+  }
   nodeInit(options);
 
   const filterTransactions: EventProcessor = event => {

packages/nextjs/test/index.server.test.ts

@@ -139,6 +139,24 @@ describe('Server init()', () => {
     });
   });
 
+  it('should not fail on valid tunnel option', () => {
+    expect(() =>
+      init({
+        dsn: 'https://dogsarebadatkeepingsecrets@squirrelchasers.ingest.sentry.io/12312012',
+        tunnel: 'https://example.com/api',
+      }),
+    ).not.toThrowError();
+  });
+
+  it('should fail on invalid tunnel option', () => {
+    expect(() =>
+      init({
+        dsn: 'https://dogsarebadatkeepingsecrets@squirrelchasers.ingest.sentry.io/12312012',
+        tunnel: '/invalid',
+      }),
+    ).toThrowError('The tunnel option is not a valid URL. It must be a full URL including the protocol.');
+  });
+
   describe('integrations', () => {
     // Options passed by `@sentry/nextjs`'s `init` to `@sentry/node`'s `init` after modifying them
     type ModifiedInitOptions = { integrations: Integration[] };