Fatal Exception: java.lang.IllegalArgumentException: The generic type <V extends MvpView> must be the first generic type argument of class

[ptsiogas]

Mosby Version:
3.1.1

Expected behavior
Not to crash.

Actual behavior (include a stacktrace if crash)

Fatal Exception: java.lang.IllegalArgumentException: The generic type <V extends MvpView> must be the first generic type argument of class PostRegisterPresenter (per convention). Otherwise we can't determine which type of View this Presenter coordinates.
       at com.hannesdorfmann.mosby3.mvp.MvpNullObjectBasePresenter.<init>(MvpNullObjectBasePresenter.java:73)
       at mypackage.com.sdk.ui.base.BasePresenter.<init>(BasePresenter.java:15)
       at mypackage.com.sdk.ui.flow.register.PostRegisterPresenter.<init>(PostRegisterPresenter.java:16)
       at mypackage.com.sdk.core.di.module.PresenterModule.providePostRegisterPresenter(PresenterModule.java:227)
       at mypackage.com.sdk.core.di.module.PresenterModule_ProvidePostRegisterPresenterFactory.providePostRegisterPresenter(PresenterModule_ProvidePostRegisterPresenterFactory.java:29)
       at mypackage.com.sdk.core.di.component.DaggerLiveDIComponent.injectPostRegisterFragment(DaggerLiveDIComponent.java:786)
       at mypackage.com.sdk.core.di.component.DaggerLiveDIComponent.inject(DaggerLiveDIComponent.java:516)
       at mypackage.com.sdk.ui.flow.register.PostRegisterFragment.injectFragment(PostRegisterFragment.java:76)
       at mypackage.com.sdk.ui.base.BaseFragment.onAttach(BaseFragment.java:115)
       at androidx.fragment.app.Fragment.onAttach(Fragment.java:1603)
       at androidx.fragment.app.Fragment.performAttach(Fragment.java:2673)
       at androidx.fragment.app.FragmentStateManager.attach(FragmentStateManager.java:263)
       at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1182)
       at androidx.fragment.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1255)
       at androidx.fragment.app.FragmentTransition.calculateFragments(FragmentTransition.java:1138)
       at androidx.fragment.app.FragmentTransition.startTransitions(FragmentTransition.java:136)
       at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2001)
       at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1959)
       at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1861)
       at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
       at android.os.Handler.handleCallback(Handler.java:873)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loop(Looper.java:214)
       at android.app.ActivityThread.main(ActivityThread.java:7094)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)

Caused by java.lang.ClassCastException: libcore.reflect.TypeVariableImpl cannot be cast to java.lang.Class
       at com.hannesdorfmann.mosby3.mvp.MvpNullObjectBasePresenter.<init>(MvpNullObjectBasePresenter.java:58)
       at mypackage.com.ui.base.BasePresenter.<init>(BasePresenter.java:15)
       at mypackage.com.ui.flow.register.PostRegisterPresenter.<init>(PostRegisterPresenter.java:16)
       at mypackage.com.core.di.module.PresenterModule.providePostRegisterPresenter(PresenterModule.java:227)
       at mypackage.com.core.di.module.PresenterModule_ProvidePostRegisterPresenterFactory.providePostRegisterPresenter(PresenterModule_ProvidePostRegisterPresenterFactory.java:29)
       at mypackage.com.core.di.component.DaggerLiveDIComponent.injectPostRegisterFragment(DaggerLiveDIComponent.java:786)
       at mypackage.com.core.di.component.DaggerLiveDIComponent.inject(DaggerLiveDIComponent.java:516)
       at mypackage.com.ui.flow.register.PostRegisterFragment.injectFragment(PostRegisterFragment.java:76)
       at mypackage.com.ui.base.BaseFragment.onAttach(BaseFragment.java:115)
       at androidx.fragment.app.Fragment.onAttach(Fragment.java:1603)
       at androidx.fragment.app.Fragment.performAttach(Fragment.java:2673)
       at androidx.fragment.app.FragmentStateManager.attach(FragmentStateManager.java:263)
       at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1182)
       at androidx.fragment.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1255)
       at androidx.fragment.app.FragmentTransition.calculateFragments(FragmentTransition.java:1138)
       at androidx.fragment.app.FragmentTransition.startTransitions(FragmentTransition.java:136)
       at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2001)
       at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1959)
       at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1861)
       at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
       at android.os.Handler.handleCallback(Handler.java:873)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loop(Looper.java:214)
       at android.app.ActivityThread.main(ActivityThread.java:7094)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)

Our classes:

@EFragment
public class PostRegisterFragment extends BaseFragment<PostRegisterView, PostRegisterPresenter> implements PostRegisterView

public abstract class BaseFragment<V extends BaseView, P extends BasePresenter<V>> extends MvpFragment<V, P> implements BaseView

public interface PostRegisterView extends BaseView

public interface BaseView extends MvpView

public class PostRegisterPresenter extends BasePresenter<PostRegisterView>

public abstract class BasePresenter<V extends BaseView> extends MvpNullObjectBasePresenter<V>

Steps to reproduce the behavior or link to a sample repository

• We received the logs from Google Play Store crashlytics. Until now we do not have any replication steps.
• It seems that it doesn't affect all of our users.
• Also we have proguard enabled.
• The issue appeared out of the blue, we did not made any changes at those classes in our latest release.
• We used to have mosby 2.0.1 when we first got the issue yesterday, we updated to 3.1.1 in order to fix the problem.
• The problem seems to be contained a little but it still persists.

[ptsiogas]

Guys do you have any news about that? Is this project still active?

[luiscurini]

Hi!

I'm not quite sure why this is happening. I'm encountering the same issue but only with AS gradle plugin 4.2+ and gradle 6.7+. I reverted my configuration to use temporarily gradle plugin 4.1.3 and gradle 6.5.

This seems to me like an R8 / proguard rule that it's missing. Debug builds, which are not obfuscated, work without any issues.

[Stonos]

Try adding the following keep rules if you're using R8 with Full Mode enabled:

-keep,allowobfuscation,allowshrinking class com.hannesdorfmann.mosby3.mvp.MvpNullObjectBasePresenter { *; }
-keep,allowobfuscation,allowshrinking class * extends com.hannesdorfmann.mosby3.mvp.MvpNullObjectBasePresenter