Gson crashes when minified with R8 strict mode

[wiyarmir]

The proguard rules are not exhaustive enough, and crash when running R8 in strict mode.

Here <init>() is being accessed by reflection but not kept:

Auth0.Android/auth0/src/main/java/com/auth0/android/authentication/storage/SecureCredentialsManager.kt

Line 436 in 801140e

val bridgeCredentials = gson.fromJson(json, OptionalCredentials::class.java)

Example stacktrace:

java.lang.RuntimeException: Unable to create instance of class mdi.sdk.jr5. Registering an InstanceCreator or a TypeAdapter for this type, or adding a no-args constructor may fix this problem.
    com.google.gson.internal.ConstructorConstructor$16.construct(ConstructorConstructor.java:275)
    com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:211)
    com.auth0.android.request.internal.JsonRequiredTypeAdapterFactory$1.read(JsonRequiredTypeAdapterFactory.java:31)
    com.google.gson.TypeAdapter$1.read(TypeAdapter.java:199)
    com.google.gson.Gson.fromJson(Gson.java:991)
    com.google.gson.Gson.fromJson(Gson.java:956)
    com.google.gson.Gson.fromJson(Gson.java:905)
    com.google.gson.Gson.fromJson(Gson.java:876)
    com.auth0.android.authentication.storage.SecureCredentialsManager.continueGetCredentials$lambda-3(SecureCredentialsManager.java:436)
    com.auth0.android.authentication.storage.SecureCredentialsManager$$InternalSyntheticLambda$1$c09ebe59feb1659569cade6fd369c5089a7c5416c6136c04dd1d923283ecba7f$0.run(SecureCredentialsManager.java:85)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637)
    java.lang.Thread.run(Thread.java:1012)
Caused by: java.lang.UnsupportedOperationException: Abstract class can't be instantiated! Class name: mdi.sdk.jr5
    com.google.gson.internal.UnsafeAllocator.assertInstantiable(UnsafeAllocator.java:121)
    com.google.gson.internal.UnsafeAllocator$1.newInstance(UnsafeAllocator.java:49)
    com.google.gson.internal.ConstructorConstructor$16.construct(ConstructorConstructor.java:272)
    com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:211)
    com.auth0.android.request.internal.JsonRequiredTypeAdapterFactory$1.read(JsonRequiredTypeAdapterFactory.java:31)
    com.google.gson.TypeAdapter$1.read(TypeAdapter.java:199)
    com.google.gson.Gson.fromJson(Gson.java:991)
    com.google.gson.Gson.fromJson(Gson.java:956)
    com.google.gson.Gson.fromJson(Gson.java:905)
    com.google.gson.Gson.fromJson(Gson.java:876)
    com.auth0.android.authentication.storage.SecureCredentialsManager.continueGetCredentials$lambda-3(SecureCredentialsManager.java:436)
    com.auth0.android.authentication.storage.SecureCredentialsManager$$InternalSyntheticLambda$1$c09ebe59feb1659569cade6fd369c5089a7c5416c6136c04dd1d923283ecba7f$0.run(SecureCredentialsManager.java:85)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1137)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:637)
    java.lang.Thread.run(Thread.java:1012)

Reproduced on AGP 7.4.0

Changes

Updated proguard rules to the ones suggested by Google.

References

Relevant Issue Tracker Bug

Testing

Build release version of app that uses SecureCredentialsManager and run.

Checklist

• I have read the Auth0 general contribution guidelines

• I have read the Auth0 Code of Conduct

• All existing and new tests complete without errors

[poovamraj]

Thanks @wiyarmir, this is a really nice contribution. I will approve the workflow and check it manually once before merging this to our main branch.

[poovamraj]

LGTM 👍