fix(performance): app start frames can start with zeroed values (#3881)

Author: krystofwoldrich

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Fixes
+
+- App Start Native Frames can start with zeroed values ([#3881](https://github.com/getsentry/sentry-react-native/pull/3881))
+
 ## 5.24.0
 
 ### Features

android/src/main/java/io/sentry/react/RNSentryModuleImpl.java

@@ -381,11 +381,6 @@ public void fetchNativeFrames(Promise promise) {
                     }
                 }
 
-                if (totalFrames == 0 && slowFrames == 0 && frozenFrames == 0) {
-                    promise.resolve(null);
-                    return;
-                }
-
                 WritableMap map = Arguments.createMap();
                 map.putInt("totalFrames", totalFrames);
                 map.putInt("slowFrames", slowFrames);

ios/RNSentry.mm

@@ -415,12 +415,6 @@ - (NSDictionary*) fetchNativeStackFramesBy: (NSArray<NSNumber*>*)instructionsAdd
         NSNumber *total = [NSNumber numberWithLong:frames.total];
         NSNumber *frozen = [NSNumber numberWithLong:frames.frozen];
         NSNumber *slow = [NSNumber numberWithLong:frames.slow];
-        NSNumber *zero = [NSNumber numberWithLong:0L];
-
-        if ([total isEqualToNumber:zero] && [frozen isEqualToNumber:zero] && [slow isEqualToNumber:zero]) {
-            resolve(nil);
-            return;
-        }
 
         resolve(@{
             @"totalFrames": total,

src/js/tracing/nativeframes.ts

@@ -192,6 +192,17 @@ export class NativeFramesInstrumentation {
       },
     };
 
+    if (
+      measurements.frames_frozen.value <= 0 &&
+      measurements.frames_slow.value <= 0 &&
+      measurements.frames_total.value <= 0
+    ) {
+      logger.warn(
+        `[NativeFrames] Detected zero slow or frozen frames. Not adding measurements to traceId (${traceId}).`,
+      );
+      return null;
+    }
+
     return measurements;
   }
 

test/tracing/nativeframes.test.ts

@@ -98,6 +98,80 @@ describe('NativeFramesInstrumentation', () => {
     );
   });
 
+  it('sets native frames measurements on a transaction event (start frames zero)', async () => {
+    const startFrames = {
+      totalFrames: 0,
+      slowFrames: 0,
+      frozenFrames: 0,
+    };
+    const finishFrames = {
+      totalFrames: 100,
+      slowFrames: 20,
+      frozenFrames: 5,
+    };
+    mockFunction(NATIVE.fetchNativeFrames).mockResolvedValueOnce(startFrames).mockResolvedValueOnce(finishFrames);
+
+    await startSpan({ name: 'test' }, async () => {
+      await Promise.resolve(); // native frames fetch is async call this will flush the start frames fetch promise
+    });
+
+    await jest.runOnlyPendingTimersAsync();
+    await client.flush();
+
+    expect(client.event!).toEqual(
+      expect.objectContaining<Partial<Event>>({
+        measurements: expect.objectContaining<Measurements>({
+          frames_total: {
+            value: 100,
+            unit: 'none',
+          },
+          frames_slow: {
+            value: 20,
+            unit: 'none',
+          },
+          frames_frozen: {
+            value: 5,
+            unit: 'none',
+          },
+        }),
+      }),
+    );
+  });
+
+  it('does not sent zero value native frames measurements', async () => {
+    const startFrames = {
+      totalFrames: 100,
+      slowFrames: 20,
+      frozenFrames: 5,
+    };
+    const finishFrames = {
+      totalFrames: 100,
+      slowFrames: 20,
+      frozenFrames: 5,
+    };
+    mockFunction(NATIVE.fetchNativeFrames).mockResolvedValueOnce(startFrames).mockResolvedValueOnce(finishFrames);
+
+    await startSpan({ name: 'test' }, async () => {
+      await Promise.resolve(); // native frames fetch is async call this will flush the start frames fetch promise
+    });
+
+    await jest.runOnlyPendingTimersAsync();
+    await client.flush();
+
+    expect(client.event!).toEqual(
+      expect.objectContaining<Partial<Event>>({
+        measurements: expect.toBeOneOf([
+          expect.not.objectContaining<Measurements>({
+            frames_total: expect.any(Object),
+            frames_slow: expect.any(Object),
+            frames_frozen: expect.any(Object),
+          }),
+          undefined,
+        ]),
+      }),
+    );
+  });
+
   it('does not set measurements on transactions without startFrames', async () => {
     const startFrames = null;
     const finishFrames = {