Unit Tests

Normally, code should be tested (explicitly or implicitly) by FAT tests which run test applications that access APIs exposed by configured features. This is partly because unit tests are only run during compile/build phase, and when the full test suites are run, the compile/build phase is generally only run on one or a few machines, rather than all of them (FAT tests run on all).

However, in some cases, it may be useful to write unit tests outside of the FAT infrastructure.

Unit tests are housed within the test subfolder of a project.

Adding Unit Tests to a Project that doesn't have them

1. Add to .classpath:

   <classpathentry kind="src" output="bin_test" path="test"/>
   

2. Add to bnd.bnd:

   -testpath: \
     ../build.sharedResources/lib/junit/old/junit.jar;version=file
   

Logging for Unit Tests

If you want to capture the trace.log and messages*.log in the collected regression cloud tests then you can do this in the Java Junit tearDown method with:

        outputMgr.copyTraceStream();
        outputMgr.copyMessageStream();

e.g. have a look at this https://github.com/OpenLiberty/open-liberty/pull/25810/files#diff-b95e89cebd843b07c2f84aea4a6b5ce02ee4b732a9ed889d89caf7c865a4f59eR86

You can also send output to the gradle log file with: add to the build.gradle file (or create one) and add:

test {
    testLogging {
        outputs.upToDateWhen {false}
        showStandardStreams = true
    }
}

Running Unit Tests

Different ways to run unit tests:

• ./gradlew com.ibm.ws.whatever:test
• ./gradlew com.ibm.ws.whatever:build
• In Eclipse, right-click on the test directory and select Run As > JUnit Test
• If you want a code coverage report to be generated (in addition to running the unit tests), you can do ./gradlew com.ibm.ws.whatever:jacocoTestReport - the report is output to com.ibm.ws.whatever/build/libs/reports/jacoco/test/html/jacoco-sessions.html

Running Individual Classes/Tests

Individual tests can be run using --tests followed by the fully qualified class or test name.

./gradlew com.ibm.ws.whatever:test --tests com.ibm.ws.whatever.ImportantTest

./gradlew com.ibm.ws.whatever:test --tests com.ibm.ws.whatever.ImportantTest.testImportantThings

Note: Using --tests seems to cause a lot of additional startup with bnd, so it can take over a minute to initialize before running the tests.

Debugging Unit Tests

Tests can be debugged by attaching the Eclipse debugger. Start by adding the --debug-jvm flag to your gradle command. For example:

./gradlew com.ibm.ws.whatever:test --debug-jvm

By default this will pause before running tests, and wait for a debugger to attach on port 5005.

In eclipse, create a Debug Configuration for Remote Java Application for the project containing the unit tests. Under Connection Properties, set the port to 5005.

When gradle says Listening for transport dt_socket at address: 5005 run the eclipse debug configuration.

Adding test-only dependencies

If you need to add extra dependencies to your unit test classpath, do so via -testpath in bnd.bnd instead of -buildpath. Note that -buildpath gets inherited into the -testpath.