Classpath scanning does not work in tests using the module path [SPR-16977]

Andy Wilkinson opened SPR-16977 and commented

It appears the classpath scanning doesn’t work when Surefire launches the JVM configured to use the module path. target/classes is placed on the module path and target/test-classes is patched into this module but classpath scanning only finds classes in target/test-classes.

I have attached a minimal sample that should reproduce the problem when built (mvn test) with Java 10. The sysout from the test should show that only the test class has been found:

[INFO] Running com.example.ScanningTest
[file [/Users/awilkinson/dev/temp/module-path-scanning/target/test-classes/com/example/ScanningTest.class]]

To my rather untrained eye, building with -X and examining the arguments that Surefire uses to launch the forked JVM (in target/surefire) suggests that Surefire’s configuration of the JVM is correct.

When the sample is modified to work with Java 8 (remove module-info.java and change the compiler plugin configuration to remove <release>10</release>) the class in target/classes is also found:

[INFO] Running com.example.ScanningTest
[file [/Users/awilkinson/dev/temp/module-path-scanning/target/test-classes/com/example/ScanningTest.class], file [/Users/awilkinson/dev/temp/module-path-scanning/target/classes/com/example/One.class]]

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Affects: 5.0.7

Reference URL: https://github.com/spring-projects/spring-boot/issues/13581

Attachments:

• module-path-scanning.zip (3.66 kB)

Issue Links:

• #20937 Compatibility with JDK 11

2 votes, 7 watchers

[kopper]

I had the same (or very similar) issue running tests with maven-failsafe-plugin 3.0.0-M5 on AdoptOpen JDK 11. The work around is to disable using module path in plugin’s configuration <useModulePath>false</useModulePath>

[eiswind]

Another year has passed. To me this still is a showstopper.