Add method to control native tracing

[wbinarytree]

Currently when set a tracesSampleRate or tracesSampler. It's not sync into native during initNativeSdk. However if I set autoInitializeNativeSdk to false. The frame data from RNSentryModule will be lost because of native sdk isn't initialized via RNSentryModule. The only thing I can do for that is using patch-package to have a tracesSampleRate or tracesSampler to have both. I'm not sure this is expected feature or unexpected bug. I leave it as feature request here.

[bruno-garcia]

Sorry for the delay on replying. We have disabled passing down these values from JS into Native because that would result in double-reporting transactions. And the transactions from Native are not necessarly actionable from your end if you're writing JS.

What are you trying to accomplish by setting this flag?

[wbinarytree]

I can understand that tracesSampleRate/tracesSampler can not be transmit to native especially for tracesSampler. However when I disable autoInitializeNativeSdk. I would assume I can still have frame tracing enabled. Which is the case for iOS but not for Android. Here is my work around by use patch-package

in RNSentryModule:

public class RNSentryModule extends ReactContextBaseJavaModule {
  //.. other methods
     
   // same code from initNativeSdk 
   @ReactMethod
    public void enablePerformance() {
                      if (androidXAvailable) {
                    frameMetricsAggregator = new FrameMetricsAggregator();
                    final Activity currentActivity = getCurrentActivity();

                    if (frameMetricsAggregator != null && currentActivity != null) {
                        try {
                            frameMetricsAggregator.add(currentActivity);
                        } catch (Throwable ignored) {
                            // throws ConcurrentModification when calling addOnFrameMetricsAvailableListener
                            // this is a best effort since we can't reproduce it
                            logger.warning("Error adding Activity to frameMetricsAggregator.");
                        }
                    }
                } else {
                    logger.warning("androidx.core' isn't available as a dependency.");
                }
    }
  //.. other methods
}

in my App.js:

      Sentry.init({});
      if (Platform.OS === "android") {
        NativeModules.RNSentry.enablePerformance();
      }

[marandaneto]

If you want to enable performance on the Native SDKs, you can do with https://docs.sentry.io/platforms/react-native/manual-setup/native-init/ Maybe we should init the frameMetricsAggregator variable even if autoInitializeNativeSdk is disabled, but enableAutoPerformanceTracking is enabled, agreed, otherwise it's more boilerplate for the final user.

[wbinarytree]

@marandaneto Yeah but that would not add frame data into my JavaScript transaction. In order to have both tracesSampleRate on native and react-native. I need to disable JS auto init native SDK. Init native SDK myself. then use the alternative I provide about to enable frame rate data in react-native.

Maybe we should init the frameMetricsAggregator variable even if autoInitializeNativeSdk is disabled

That's exactly what I'm looking for. frameMetricsAggregator probably shouldn't be part of nativeInit.

[marandaneto]

Relates to https://github.com/getsentry/sentry-cocoa/issues/2262