fix(sveltekit): Don't crash build when CLI credentials are missing (#7846)

Previously, a project build would crash when users didn't specify org, project slugs or auth tokens. This patch fixes that by catching the error and providing additional information to the Sentry CLI error message.

Author: Lms24

packages/sveltekit/src/vite/sourceMaps.ts

@@ -94,7 +94,7 @@ export function makeCustomSentryVitePlugin(options?: SentryVitePluginOptionsOpti
 
     // We need to start uploading source maps later than in the original plugin
     // because SvelteKit is still doing some stuff at closeBundle.
-    closeBundle: () => {
+    closeBundle: async () => {
       if (!upload) {
         return;
       }
@@ -131,8 +131,21 @@ export function makeCustomSentryVitePlugin(options?: SentryVitePluginOptionsOpti
         }
       });
 
-      // @ts-ignore - this hook exists on the plugin!
-      sentryPlugin.writeBundle();
+      try {
+        // @ts-ignore - this hook exists on the plugin!
+        await sentryPlugin.writeBundle();
+      } catch (_) {
+        // eslint-disable-next-line no-console
+        console.warn('[Source Maps Plugin] Failed to upload source maps!');
+        // eslint-disable-next-line no-console
+        console.log(
+          '[Source Maps Plugin] Please make sure, you specified a valid Sentry auth token, as well as your org and project slugs.',
+        );
+        // eslint-disable-next-line no-console
+        console.log(
+          '[Source Maps Plugin] Further information: https://github.com/getsentry/sentry-javascript/blob/develop/packages/sveltekit/README.md#uploading-source-maps',
+        );
+      }
     },
   };