Tested on Mac, tests are working as expected.
I have included some notes below based on discussion with Sravani.
In the project pom.xml, the following line is required:
<configuration>
<argLine>-XX:+EnableDynamicAgentLoading</argLine>
</configuration>
This is due to mockito using byte-buddy-agent which causes the warning in Java 21 - see https://openjdk.org/jeps/451 and https://github.com/raphw/byte-buddy/issues/1396
Testing is successful with no internet for the two test files (UCSCRestSymloaderTest and RestApiDataProviderTest) - indicating the tests do not need access to the UCSC API (i.e. the results are being successfully mocked).
Also modified is EndPointTest.java in the ExternalView plugin to test the UCSC API. If the API is not available then several warnings should be thrown, but the build will not fail.
Written test cases to test all methods in RestApiDataProvider class, currently working on UCSCRestSymLoader, written a test case but it isn't working when I create the Symloader directly, investigating a way to make it work. Also, found a way to debug the application using IntelliJ run configuration: Add a JAR file configuration with VM options, copy and paste all the options available in run_igb.sh file into the VM options.