Building animal sniffer signatures directly from android corelib

[LikeTheSalad]

Android corelib or desugar_jdk lib is a jar containing missing JDK8 classes from Android OS versions below API 26. The idea is that apps targeting old Android devices, where said classes are missing, can add those into the app itself to avoid NoClassDefFoundException runtime errors in old devices. More info here.

However, the corelib doesn't have ALL the JDK8 missing classes, so we need to make sure we don't use those in order to avoid Android runtime exceptions. That's where Animal Sniffer helps, by checking our codebase against a signature that contains all the info about the classes available at runtime in old Android devices, both from the OS itself and from the corelib as well.

Since the corelib version of gummy-bears is not currently up-to-date with the latest corelib/desugar lib changes from Google, these changes aim to locally generate our android animal sniffer signature directly from the android lib, while also extending gummy-bears' existing plain (without the corelib parts, just the OS runtime classes) signature by following this guide on how to create/extend signatures for animal sniffer.

[LikeTheSalad]

I tested that it works by adding some code that uses java.util.Base64 and then running the task animalsnifferMain which completed without any issues (since Base64 was added in version 2.0.4). Then I changed this version to 2.0.3 and re-run the animal sniffer task which then failed.

[jack-berg]

This is awesome! I'm on board with this approach. Gives us more control and centralizes the declaration of all the versions that comprise the android compatibility we ensure.

[trask]

I agree, very nice to be explicit about the desugaring version requirement 👍

[LikeTheSalad]

Cool! I'll address the CI issues and move it to ready for review then 👍

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (b03ec3a) 91.12% compared to head (a06a0ac) 91.18%.
Report is 13 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #5973      +/-   ##
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+ Coverage     91.12%   91.18%   +0.05%     
- Complexity     5599     5613      +14     
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  Files           615      616       +1     
  Lines         16519    16566      +47     
  Branches       1639     1642       +3     
============================================
+ Hits          15053    15105      +52     
+ Misses         1014     1013       -1     
+ Partials        452      448       -4     

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[jack-berg]

Just a couple of small comments. Thanks for doing this!

[jack-berg]

How about animal-sniffer-signature?

[LikeTheSalad]

Sure no problem, I've made the changes.

[jack-berg]

Let's move google() to the repositories section of settings.gradle.kts, and delete mavenCentral() since its redundant.

[LikeTheSalad]

Thanks, it's updated now.

[jack-berg]

Is it possible to define these in dependencyManagement/build.gradle.kts and omit the versions here?

[LikeTheSalad]

I tried with both but it only worked for com.android.tools:desugar_jdk_libs so that's the only one I moved over to dependencyManagement. I'm guessing the @signature part of gummy-bears makes it difficult for Gradle to resolve the artifact when the version is defined elsewhere.