Use ByteBuddy to instrument classes instead Javassist

[thekingn0thing]

The main issue with Javassist it's that it read classes from disk before instrumenting. Such behaviour breaks compatibility with other tools which are instrumenting classes (see discussion jacoco/jacoco#51)

ByteBuddy could help us to resolve the issue and supporting online Jacoco Instrumenting.

ByteBudy agent has to be used for implementation of powermock-agent

[fabriziomieli]

Hi, When this is supposed to be ready?

[thekingn0thing]

Hi, I hope I will finish by the end of June. I've created an issue for ByteBuddy project to clarify what is possible to do with using ByteBuddy (raphw/byte-buddy#296). Best regrads, Arthur Zagretdinov On 26 Apr 2017, at 10:49, fabriziomieli <notifications@github.com<mailto:notifications@github.com>> wrote: Hi, When this is supposed to be ready? — You are receiving this because you were assigned. Reply to this email directly, view it on GitHub<#727 (comment)>, or mute the thread<https://github.com/notifications/unsubscribe-auth/AMkKAFdZCxJDidiRZ435ivYLJgm0Tsbyks5rzwUkgaJpZM4LBFW1>.

[fabriziomieli]

Thank you very much

[peter-janssen]

Will you release this feature when it is ready or only as part of PowerMock 2.0?

[thekingn0thing]

I'm going to release it as part of PowerMock 2.0, because the change for ButyBuddy is close intertwined with clearing PowerMock from copy-pasted mockito code.

[peter-janssen]

The 2.0 release looks quite big so I guess the earlier estimate of end of june (you did mean 2017, right?) will be pushed back quite a bit?

[benken-parasoft]

Thanks for the update. For background, enterprise users like myself are moving ahead with newer java releases which now release every six months. For existing unit test bases that use powermock, we have to either switch to 2.x or hold our entire unit test bases to older java versions.

the last beta was released last May

Thanks for the clarification. I only found the source tag but not any released binaries. Up until now, I've always pulled powermock releases from maven central, including the latest 1.7.4 release from April. Are you no longer releasing binaries to maven central for 2.x? Was this intentional or an oversight? Or should users stop using maven central and use the maven repository from bintray instead?

[thekingn0thing]

@benken-parasoft,

I only found the source tag but not any released binaries. Up until now, I've always pulled powermock releases from maven central, including the latest 1.7.4 release from April. Are you no longer releasing binaries to maven central for 2.x? Was this intentional or an oversight?

It was done intentionally as I don't want to span Maven Central with a lot of beta version. PowerMocks migrated to continue delivery, so it means that each pull request merged to release branches is being published to a repository as an artifact. However, I understood that could development PowerMock 2.0 could take a lot time (not so many as it already has taken), I decided to split beta release to Bintray and GA release to maven central.

[thekingn0thing]

I'm excluding this feature from PowerMock 2.0.0 as working on it took to many time and I'm not able to finish it in near future. I will release PowerMock 2.0.0 with all changes and full supporting Mockito 2.x and then will continue work on this feature as a part of PowerMock 3.x where I will drop supporting Java less than 1.8

[Tibor17]

@thekingnothing
I respect your decision.
I think here your work is to use very low level bytecode instructions. I saw similar work in JaCoCo project. So. If you involved committers from JaCoCo, their experiences would be beneficial and you would have more spare time for yourself.

[benken-parasoft]

@thekingnothing, I notice ByteBuddy changes backed out as part of PR 948. Then I saw PR 910 mentioned in the release notes 2.0.0 RC1 but I assume this is just referring to what you had backed out. However, I still might not be understanding these changes correctly. Can you clarify what is or isn't being included with respect to ByteBuddy for the 2.0.0 release?

I am primarily concerned about java version support. My organization needs to be able to support new Java releases as they come out, which is now every six months. Based on my observations, this appears to depend on which version of what byte code library being used, ByteBuddy vs Javassist. For example, I seemed to be able to do static mocking in Java 11 with PowerMock 2.0.0 beta 11 with Mockito 2.23 and ByteBuddy 1.9. So, if PowerMock 2.0.0 switches back to using Javassist then will static mocking no long work in java > 8 again? To support new java, such as java 11, will I be able to switch to the 2.0.0 release or should I should stay on beta 11 or use later a 3.0 snapshot with preliminary ByteBuddy support re-introduced?

[benken-parasoft]

I am primarily concerned about java version support.

With PowerMock 22 using Javassist again, it looks like PowerMock would only work with Java 9 but not 10 or 11. At least, the pom.xml for PowerMock 2.0.0-RC.2 shows a dependency on Javassist 3.22.0-GA which looks to support Java 9. Perhaps it be possible to use PowerMock with Javassist 3.24.0-GA for Java 11 support instead? Previously, with PowerMock 2.0.0 beta 11, I was able to use ByteBuddy 1.9 for Java 11 support.

[thekingn0thing]

@benken-parasoft

I agree that ByteBuddy is a great well-supported library. However, it does not cover all PowerMock needs, at least for now.

It’s well applied when you need advice your code or generates a code. However, to support such features as constructor stubbing, mocking constructor calls or mocking System class I have to modify bytecode in instruction level where ByteBuddy features end. I have only one option - use ASM in addition to ByteBuddy. As it means that I have to:

• go deep into JVM implantation.
• manually track stack, local variables and so on (with a help from the ByteBuddy side, however, there are still a lot of work to do)
• care about JVM changes and aspect of implementation

As result, it takes a lot of time to implement the features that already worked with Javassist. I tried to implement it for 6 months, however, with a time that I can give to PowerMock I did not achieve a big progress. The task is too complicated. You need fully focus on it - what hardly achievable when you work for 30-60 minutes per day.

I’m not going to stop working at all on migrating to ByteBuddy. I just changed priorities to be able to release what was already implemented the year ago.

At the end of the day, my decision is aimed to be able to deliver supporting new Java. Thank @ijuma, he provided the pull request to support Java 11 (#952) and @eolivelli who raised the pull request with the fix for Java 12 (#939).

[jhyry-gcpud]

Is this issue still on the table?

[Tibor17]

I understand it so that ByteBuddy should be on the table. Without it the JaCoCo report would not cover these tests with PowerMock or Mockito. At least this is my understanding, and some people would see other reasons especially internal ones in PowerMock.

[nEdAy]

Is this issue still on the table?

[vijjukumar]

Is this issue still on the table ? we do have any alternative approach. Thanks

[Vampire]

How is the current state of this?
I used JaCoCo online instrumentation with PowerMock for mocking a system class.
It seems there was JaCoCo data recorded, but it doesn't match the class files when the report is generated, so I guess only the order of instrumentation is a problem maybe?

[ninjubohra]

Hello,

Just another user affected by the 'zero' JaCoCo results with Powermock 😢
The top of this issue thread now says that the issue was fixed by another issue (#911 )

If so can somebody do the following:

• Add an 'affirmative' message to the thread and close issue
• Update the Powermock documentation here to reflect the updated state
• Have a virtual cookie in appreciation of all the hard work that goes into supporting a great tool like Powermock (thanks!) 🍪

[Techtony96]

The PR #911 that says fixes this issue is unrelated and must be a typo in the commit message.

As a user eagerly awaiting online instrumentation I thank you for all the hard work towards this goal.

[fredwilliamson]

Hello ByteBuddy implementation will be in your next release ?
BR

[chengyinjie]

Really looking forward to the ByteBuddy release to fix the Jacoco problem.

[minhnguyenvan95]

Looking forward to ByteBuddy release

[OluwoleOyetoke]

Really looking forward to the ByteBuddy release

[splf32]

Really looking forward to the ByteBuddy release

[SangHakLee]

Really looking forward to the ByteBuddy release.

I want to use JaCoCo and Powermock comfortably.

[jhyry-gcpud]

Been watching this thread for over a year.
Any progress?

[sarajcarbajal]

any progress with this issue?