StackWalker.Option not found on Mockito 5.1.0

[sergiandreplace]

We have an Android project using Mockito and we tried to upgrade from 5.0.0 to 5.1.0.

When running the Android tests we always receive an error like this:

java.lang.NoClassDefFoundError: Failed resolution of: Ljava/lang/StackWalker$Option;
	at org.mockito.internal.debugging.LocationImpl.stackWalker(LocationImpl.java:138)
	at org.mockito.internal.debugging.LocationImpl.<clinit>(LocationImpl.java:40)
	at org.mockito.internal.debugging.LocationFactory.create(LocationFactory.java:17)
	at org.mockito.internal.debugging.LocationFactory.create(LocationFactory.java:13)
	at org.mockito.internal.matchers.LocalizedMatcher.<init>(LocalizedMatcher.java:19)
	at org.mockito.internal.progress.ArgumentMatcherStorageImpl.reportMatcher(ArgumentMatcherStorageImpl.java:30)
	at org.mockito.ArgumentMatchers.reportMatcher(ArgumentMatchers.java:1036)
	at org.mockito.ArgumentMatchers.any(ArgumentMatchers.java:177)
	...

After some investigation we found that:

• StackWalker is only available from Java 9. All our modules are setup to use Java 11.
• We can't see StackWalker class from the IDE
• This only happens on Android instrumental tests, not in "normal" java tests
• The class StackWalker is not available in Android SDK java implementation: https://github.com/AndroidSDKSources/android-sdk-sources-for-api-level-33/tree/master/java/lang (that would explain why is not working only for instrumental tests, as they are executed on an Android device). Checked for latest android versions.

It looks like a very specific Android issue.

For the meantime, we will halt the upgrade, but any help will be great.

Thanks in advance

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[TimvdLippe]

Two questions:

1. Are you using mockito-android?
2. Does a later version of Android ship the API?

[zsoltvilagos]

@TimvdLippe I hope @sergiandreplace doesn't mind if I answer.

We're also using Mockito and ran into the very same problem.

1. Are you using mockito-android?
   We're using mockito-android, same version 5.1.0 as mockito-core.

2. Does a later version of Android ship the API?

Nope. API 33 is the latest version, Android 13.

[SmasSive]

@TimvdLippe a colleague of Sergi here! Yes, we are using mockito-android (5.1.0 same version of core).
And as @zsoltvilagos said, no... The latest version of Android (SDK 33) does not include the API.

[TimvdLippe]

@reta if I understand correctly, we would have to revert the StackWalker change, but that would break your integration with the SecurityManager. Can we figure out a solution that would satisfy both?

[reta]

@TimvdLippe unexpected, but I agree, we probably have to revert at least the StackWalker changes and use the reflection for Android, sorry about that. I could look into it tonight if that is fine with you. Thank you.

Can we figure out a solution that would satisfy both?

Yes, I believe we can

[TWiStErRob]

Here's a minimal repro in case you want to test things out (or add an integration test for a basic case):

1. https://github.com/TWiStErRob/repros/tree/master/mockito/mockito5_StackWalkerOption
2. Unit Tests: gradlew testDebugUnitTest
   report: ./build/reports/tests/testDebugUnitTest/index.html
3. Instrumentation Tests: gradlew connectedCheck
   report: ./build/reports/androidTests/connected/index.html
4. Instrumentation Tests (alternative): gradlew pixel2api33DebugAndroidTest
   report: ./build/reports/androidTests/managedDevice/allDevices/index.html

Note: connectedCheck and pixel2api33DebugAndroidTest are almost equivalent, but pixel2api33DebugAndroidTest only needs an SDK installed, it will download and set up the emulator automatically.

I used a realistic but pointless mocking setup, also it repros using just mock() too.

Results

Mockito 5.1.0 (committed to repro):

• gradlew testDebugUnitTest: ✅ passes
• gradlew connectedCheck: ❌ fails
  NoClassDefFoundError: Failed resolution of: Ljava/lang/StackWalker$Option;
• gradlew pixel2api33DebugAndroidTest: ❌ fails
  NoClassDefFoundError: Failed resolution of: Ljava/lang/StackWalker$Option;

Mockito 5.0.0 (for control, change def mockito in build.gradle):

• gradlew testDebugUnitTest: ✅ passes
• gradlew connectedCheck (API 21): ❌ fails
  NoClassDefFoundError: org.mockito.internal.invocation.TypeSafeMatching$$ExternalSyntheticLambda0
• gradlew connectedCheck (API 31): ✅ passes
• gradlew pixel2api33DebugAndroidTest (API 33): ✅ passes

Mockito 4.11.0 (for control, change def mockito in build.gradle):

• gradlew testDebugUnitTest: ✅ passes
• gradlew connectedCheck (API 21): ❌ fails
  NoClassDefFoundError: org.mockito.internal.invocation.TypeSafeMatching$$ExternalSyntheticLambda0
• gradlew connectedCheck (API 31): ✅ passes
• gradlew pixel2api33DebugAndroidTest (API 33): ✅ passes

For reference: https://developer.android.com/reference/classes doesn't have StackWalker.

[TimvdLippe]

FWIW we started an effort to set up some basic Android tests for us: https://github.com/mockito/mockito/tree/main/subprojects/androidTest However, this stalled as we couldn't get it to work on CI. If anybody affected here would like to dedicate some time to prevent these kind of issues from happening, please take a look at the existing test suite and infrastructure and submit a PR to get it passing on CI.