ClasspathScanner#determineSubpackageName sometimes resolves to wrong subpackageName starting with '...'

[hosuaby]

This bug was introduced in JUnit 5.7.1. 5.7.0 have no such a problem.

Example:

Path baseDir = "/com/fasterxml/jackson/core/base/";
Path classFile = "/com/fasterxml/jackson/core/base/ParserMinimalBase.class";
String subpackageName = determineSubpackageName(baseDir, classFile);
// subpackageName now equals "...base"

The bug is probaby due to commit #2531 (Fix package path computation in ClasspathScanner )

I got this bug because I use ReflectionSupport#findAllClassesInPackage inside my JUnit Jupiter plugin.

Steps to reproduce

To reproduce the bug is quite a trick. So project https://github.com/jlrosa/testwithresources was created. Here the steps to do

1. Clone the project, execute mvn clean install, and open the project in IDE.
2. Setup a breakpoint in ClasspathScanner#processClassFileSafely line 131.
3. Run the test InjectResourcesTest in debug mode.
4. Java debugger will stop. Check the value of the variable fullyQualifiedClassName. It will be something like: "com.adelean.inject.resources.junit.jupiter....jupiter.WithJacksonMapper"

Context

• Used versions (Jupiter/Vintage/Platform): JUnit 5.7.1
• Build Tool/IDE: Intellij

Deliverables

• ...

[sormuras]

Thanks for the report and the reproducer, Alexei.

I recently reopened #2500 in order to find a better fix -- my current plan is to revert #2531 first and write a dedicated ModulepathScanner.

[sormuras]

The URI https://github.com/jlrosa/testwithresources is wrong. Typo?

[hosuaby]

@sormuras Sorry, I forgot that project is private. I will ask author to make it public.

[hosuaby]

Hello @sormuras .

Here the repository that can be used to reproduce the bug following steps above:
https://github.com/hosuaby/junit-bug-2612

[sormuras]

Perfect timing, Alexei! I'll include it (or a similar check) in the PR I just submitted.