review comments

Author: iamAbhi-916

packages/@react-native-windows/perf-testing/src/ci/BaselineComparator.ts

@@ -106,7 +106,9 @@ export class BaselineComparator {
       base.medianDuration > 0
         ? ((head.medianDuration - base.medianDuration) / base.medianDuration) *
           100
-        : 0;
+        : head.medianDuration > 0
+          ? Infinity
+          : 0;
 
     const errors: string[] = [];
 

packages/@react-native-windows/perf-testing/src/core/measurePerf.ts

@@ -185,8 +185,11 @@ async function runSingleMeasurement(
     act(() => {
       renderer.unmount();
     });
-  } catch {
-    // Already unmounted
+  } catch (e: unknown) {
+    const msg = e instanceof Error ? e.message : String(e);
+    if (!msg.includes('unmount') && !msg.includes('not mounted')) {
+      throw e;
+    }
   }
 
   // Prefer Profiler actualDuration, fallback to manual timing

vnext/Scripts/perf/compare-results.js

@@ -88,12 +88,14 @@ function resolveThreshold(threshold) {
 }
 
 function compareEntry(head, base, threshold) {
-  // Use median for comparison — robust to outlier spikes
+  // median for comparison
   const percentChange =
     base.medianDuration > 0
       ? ((head.medianDuration - base.medianDuration) / base.medianDuration) *
         100
-      : 0;
+      : head.medianDuration > 0
+        ? Infinity
+        : 0;
 
   const errors = [];