Tests not found via classpath scanning within nested JAR in Spring Boot JAR

[ferstl]

We are providing a test suite for our applications as Spring Boot application. The test suite is basically a set of regular JUnit 5 tests that are launched in the Spring Boot application.
The application is packaged as Spring Boot JAR (created with the spring-boot-maven-plugin).

We do now have the problem, that the tests are not found when we are using DiscoverySelectors.selectPackage() and run the application as Spring Boot JAR. Everything works fine, when we select the tests by classname. Executing the application within an IDE works fine as well.

The problem seems to be in ClasspathScanner#findClassesForPath()). Files.walkFileTree() does not work with nested JAR files. A similar problem was already reported in #399.

Steps to reproduce

I created a project on GitHub to reproduce this issue. When the Application is run within the IDE, everything works fine. When it is executed as Spring Boot JAR, the test is not found.

Context

• Used versions (Jupiter/Vintage/Platform): junit-bom 5.3.2
• Build Tool/IDE: Maven, OpenJDK11, IntelliJ
• Spring Boot: 2.1.1.RELEASE

[sbrannen]

Thanks for raising the issue.

I've tentatively slated this for 5.4 M2 for the purpose of team discussion.

[sormuras]

Today I stumbled over the same problems. Thanks for creating a demo project @ferstl!

I'll a) push an integration test showing the issue is even applicable when test classes are jarred (not nested) and b) tackle the underlying missing feature/enhancement after 5.5 GA is released.