fromJson fails if multiple Levels of generics are involved

[ChrisSchoe]

Describe the bug
I was directed here from reporting this as a Quarkus bug here.
Using classes implementing generics in a certain way can lead to fromJson not working properly and failing with the stacktrace posted below:

java.lang.ClassCastException: class model.AbstractChild cannot be cast to class model.ConcreteChild (model.AbstractChild and model.ConcreteChild are in unnamed module of loader io.quarkus.bootstrap.classloading.QuarkusClassLoader @dddacdd) at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:106) at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:372) at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:218) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:519) at org.jboss.resteasy.core.SynchronousDispatcher.lambda$invoke$4(SynchronousDispatcher.java:261) at org.jboss.resteasy.core.SynchronousDispatcher.lambda$preprocess$0(SynchronousDispatcher.java:161) at org.jboss.resteasy.core.interception.jaxrs.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:364) at org.jboss.resteasy.core.SynchronousDispatcher.preprocess(SynchronousDispatcher.java:164) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:247) at io.quarkus.resteasy.runtime.standalone.RequestDispatcher.service(RequestDispatcher.java:73) at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler.dispatch(VertxRequestHandler.java:138) at io.quarkus.resteasy.runtime.standalone.VertxRequestHandler$1.run(VertxRequestHandler.java:93) at io.quarkus.vertx.core.runtime.VertxCoreRecorder$14.runWith(VertxCoreRecorder.java:481) at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2442) at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1476) at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:29) at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:29) at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) at java.base/java.lang.Thread.run(Thread.java:834) Caused by: java.lang.ClassCastException: class model.AbstractChild cannot be cast to class model.ConcreteChild (model.AbstractChild and model.ConcreteChild are in unnamed module of loader io.quarkus.bootstrap.classloading.QuarkusClassLoader @dddacdd) at org.acme.getting.started.GreetingResource.testYasson(GreetingResource.java:34) at org.acme.getting.started.GreetingResource_Subclass.testYasson$$superforward1(GreetingResource_Subclass.zig:132) at org.acme.getting.started.GreetingResource_Subclass$$function$$4.apply(GreetingResource_Subclass$$function$$4.zig:24) at io.quarkus.arc.impl.AroundInvokeInvocationContext.proceed(AroundInvokeInvocationContext.java:54) at io.quarkus.arc.runtime.devconsole.InvocationInterceptor.proceed(InvocationInterceptor.java:62) at io.quarkus.arc.runtime.devconsole.InvocationInterceptor.monitor(InvocationInterceptor.java:49) at io.quarkus.arc.runtime.devconsole.InvocationInterceptor_Bean.intercept(InvocationInterceptor_Bean.zig:521) at io.quarkus.arc.impl.InterceptorInvocation.invoke(InterceptorInvocation.java:41) at io.quarkus.arc.impl.AroundInvokeInvocationContext.perform(AroundInvokeInvocationContext.java:41) at io.quarkus.arc.impl.InvocationContexts.performAroundInvoke(InvocationContexts.java:32) at org.acme.getting.started.GreetingResource_Subclass.testYasson(GreetingResource_Subclass.zig:280) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:170) at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:130) at org.jboss.resteasy.core.ResourceMethodInvoker.internalInvokeOnTarget(ResourceMethodInvoker.java:660) at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTargetAfterFilter(ResourceMethodInvoker.java:524) at org.jboss.resteasy.core.ResourceMethodInvoker.lambda$invokeOnTarget$2(ResourceMethodInvoker.java:474) at org.jboss.resteasy.core.interception.jaxrs.PreMatchContainerRequestContext.filter(PreMatchContainerRequestContext.java:364) at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:476) at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:434) at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:408) at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:69) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:492) ... 15 more

To Reproduce
Using the model classes from the minimal example( https://github.com/ChrisSchoe/quarkus-resteasy-bug-minimal-example )
try to create an object of type ConcreteContainer from a Json-String (either given as a string or obtained via fromJson such as in the testYassonmethod here. The child-field of the resulting object is of type AbstractChild and the above error is thrown when trying to access the fields only contained in the subclass ConcreteChild.

Expected behavior
An object of type ConcreteContainer should be created and its field child should contain an object of type ConcreteChild whose fields are all accessible.

System information:

• OS: MacOS BigSur
• Java Version: 11.0.10
• Yasson Version: 1.0.9
  Note: With Yasson 1.0.8 everything works fine

[Verdent]

Hi @ChrisSchoe ,
Thank you for reaching out. It really looks like a bug. I will make a fix for this.