foundationdb/bindings/java/src

Adding JUnit tests

For java development, it's often useful to use JUnit for testing due to the excellent tooling support.

To add a new unit test, do the following:

1. Write your test
2. Add the test path to tests.cmake, using the relative path starting at src(for example, src/junit/com/apple/foundationdb/tuple/ArrayUtilTests.java will add the ArrayUtilTests test file).
3. re-run the build (both cmake and make/xcode/ninja)

To add a new integration test:

1. Write the test, using JUnit.
2. Add the test path to tests.cmake, using the relative path starting at src (i.e. src/integration/com/apple/foundationdb/DirectoryTest.java).
3. re-run the build (both cmake and make/xcode/ninja)

To run all unit and integration tests, execute ctest . from ${BUILD_DIR}/bindings/java.

To skip integration tests, execute ctest -E integration from ${BUILD_DIR}/bindings/java.

To run only integration tests, run ctest -R integration from ${BUILD_DIR}/bindings/java.

There are lots of other useful ctest commands, which we don't need to get into here. For more information, see the [https://cmake.org/cmake/help/v3.19/manual/ctest.1.html](ctest documentation).

Multi-Client tests

Multi-Client tests are integration tests that can only be executed when multiple clusters are running. To write a multi-client test, do the following:

1. Tag all tests that require multiple clients with @Tag("MultiClient")
2. Ensure that your tests have the MultiClientHelper extension present, and Registered as an extension
3. Ensure that your test class is in the the JAVA_INTEGRATION_TESTS list in test.cmake

( see BasicMultiClientIntegrationTest for a good reference example)

It is important to note that it requires significant time to start and stop 3 separate clusters; if the underying test takes a long time to run, ctest will time out and kill the test. When that happens, there is no guarantee that the FDB clusters will be properly stopped! It is thus in your best interest to ensure that all tests run in a relatively small amount of time, or have a longer timeout attached.