[3.x] RxJavaAssemblyTracking stack trace is not printed

[piomar123]

My test code:

package me.piomar.dataflow;

import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import hu.akarnokd.rxjava3.debug.RxJavaAssemblyTracking;
import io.reactivex.rxjava3.core.Flowable;
import io.reactivex.rxjava3.schedulers.Schedulers;

public class RxErrorApp {

    private static final Logger LOGGER = LoggerFactory.getLogger(RxErrorApp.class);

    public static void main(String[] args) {
        LOGGER.info("App start");
        RxJavaAssemblyTracking.enable();

        List<String> list = Flowable.just("a", "b", "c")
                                    .observeOn(Schedulers.computation())
                                    .map(RxErrorApp::bang)
                                    .toList()
                                    .blockingGet();
        LOGGER.info("Result: {}", list);
    }

    private static String bang(String input) {
        throw new IllegalStateException("bang");
    }
}

The result in console:

Exception in thread "main" java.lang.IllegalStateException: bang
	at me.piomar.dataflow.RxErrorApp.bang(RxErrorApp.java:29)
	at io.reactivex.rxjava3.internal.operators.flowable.FlowableMap$MapSubscriber.onNext(FlowableMap.java:64)
	at hu.akarnokd.rxjava3.debug.FlowableOnAssembly$OnAssemblySubscriber.onNext(FlowableOnAssembly.java:61)
	at io.reactivex.rxjava3.internal.operators.flowable.FlowableObserveOn$ObserveOnSubscriber.runSync(FlowableObserveOn.java:337)
	at io.reactivex.rxjava3.internal.operators.flowable.FlowableObserveOn$BaseObserveOnSubscriber.run(FlowableObserveOn.java:174)
	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.run(ScheduledRunnable.java:65)
	at io.reactivex.rxjava3.internal.schedulers.ScheduledRunnable.call(ScheduledRunnable.java:56)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: hu.akarnokd.rxjava3.debug.RxJavaAssemblyException
Caused by: hu.akarnokd.rxjava3.debug.RxJavaAssemblyException

As it can be seen, there is no stack trace printed inside RxJavaAssemblyException. I'm using OpenJDK11, compiling to Java 8 (tested on JDK8 with same result). During debug, it can be seen that there is String RxJavaAssemblyException.stacktrace field which has been filled properly but seems it's not used anywhere.

Maven dependencies:

        <dependency>
            <groupId>com.github.akarnokd</groupId>
            <artifactId>rxjava3-extensions</artifactId>
            <version>3.0.0</version>
        </dependency>
        <dependency>
            <groupId>io.reactivex.rxjava3</groupId>
            <artifactId>rxjava</artifactId>
            <version>3.0.5</version>
        </dependency>

[akarnokd]

It is designed to manually extract the stacktrace: https://github.com/akarnokd/RxJavaExtensions/blob/3.x/src/test/java/hu/akarnokd/rxjava3/debug/RxJava3AssemblyTrackingTest.java#L91

[piomar123]

I noticed it after deeper debugging. What about setting message field or overriding getMessage()?
This would result in printing the stack trace without the need to catch and look for the nested assembly exception.

[akarnokd]

I don't remember exactly why it doesn't do it, but most likely due to it breaking IDE stacktrace displaying.

[piomar123]

Do you remember which IDE could that be? In IntelliJ, printing it as an exception message works well.

[akarnokd]

Eclipse had certainly trouble with it. It is the very same situation as with ReactiveX/RxJava#6748 where the exception has to be carefully re-engineered.

You are welcome to try modifying the class and see if it works in Eclipse and IntelliJ as you'd expect.

[akarnokd]

Closing via #77.