Misc "?." for safety

Author: Vadorequest

src/pages/_app.tsx

@@ -125,7 +125,7 @@ export function reportWebVitals(metrics: NextWebVitalsMetrics): void {
   const { name } = metrics;
   const count = globalWebVitalsMetric.reportedCount;
   globalWebVitalsMetric.metrics[name] = metrics;
-  const keysLength = Object.keys(globalWebVitalsMetric.metrics).length;
+  const keysLength = Object.keys(globalWebVitalsMetric.metrics)?.length;
 
   // Temporise analytics API calls by waiting for at least 5 metrics to be received before sending the first report
   // (because 3 metrics will be received upon initial page load, and then 2 more upon first click)