FV3-JEDI comes with an extensive suite of ctests. These tests are designed to makes sure as much as possible of the source code in FV3-JEDI is regularly exercised and that all common applications are tested. This ensures continued functionality of the code as changes are made and saves time by not requiring code reviewers to run all the tests themselves and instead be focused on design implications.

Continuous integration

FV3-JEDI has an extensive continuous integration (CI) suite running on Amazon Web Services. Each time a pull request is issued against develop in the JCSDA public repository the FV3-JEDI part of the FV3-BUNDLE package is built with Intel, GNU and Clang compilers and all the FV3-JEDI tests are executed. Unless all the tests pass a failure blocks the pull request from being merged. In addition to running all the tests the CI includes a code coverage report. The main purpose of the code coverage test is to make sure that any changes to the code are included in one of the tests that run. If the coverage of the code that is added through the pull request is less than the coverage of the existing code it will issue a failure that blocks the merge.

Adding a test to FV3-JEDI

Having the CI means that developers are responsible for adding a test that covers any code they wish to add to the system. All the testing in FV3-JEDI is controlled through fv3-jedi/test/CMakeLists.txt. Broadly there are two kinds of ctests in FV3-JEDI, and JEDI in general. The first is a so-called interface test. These kinds of tests measure individual methods (units) in each class. It might have an expected result or allow for a result to within some tolerance. The other kind of ctest is an application test, where an entire application is run. In these application tests there is a reference log file that is compared with the actual output, usually with some tolerance to allow for small differences.

Adding a test to FV3-JEDI will typically involve at least three files, source code for the test, an executable, and a configuration file. A fourth file, a reference file, must be supplied in the case of application tests, see below. Tests need to be registered with CTest which we can do with a call to ecbuild_add_test() in the test/CMakeLists.txt file which may look something like the call below.

ecbuild_add_test( TARGET   fv3jedi_test    #name of the test
                  MPI      6    #number of MPI tasks
                  ARGS     testinput/mytest.yaml    #configuration file
                  COMMAND  fv3jedi_test.x    #executable to run
                  TEST_DEPENDS other_test_name #other test this one may depend on )

The TARGET option defines the name of the test, while the COMMAND option specifies the executable to be run. ARGS specifies the configuration file to be used while the MPI option specifies the number of MPI tasks needed. If the test you are adding depends on another test this can be specified using the TEST_DEPENDS option. In addition, with the ARGS option, you can run yaml validation only and not the test with ARGS –validate-only testinput/mytest.yaml or skip the validation and run the test only with ARGS –no-validate testinput/mytest.yaml. The best source for information on available arguments is the file that defines the macro itself, cmake/ecbuild_add_test.cmake in ECMWF’s ecbuild repository.

In addition to registering the test with CTest, we also must let it know about the configuration file, “mytest.yaml”. To do this, edit the CMakeLists.txt file and look for a list of input files like this one from fv3-jedi/test/CMakeLists.txt:

list( APPEND fv3jedi_testinput
  testinput/mytest.yaml    #add your configuration file

When adding an application test for which you want to compare the output of the test executable to a known solution, a test reference file, “mytest.ref”, must also be provided. Reference files define the known solutions and are found in the test/testoutput. These files must also be specified in fv3-jedi/test/CMakeLists.txt: e.g.

list( APPEND fv3jedi_testoutput
  testoutput/mytest.ref    # add your reference file

If you need to generate your own reference file, the file can be generated by running the application with the test configuration and writing the output to a log file. The below provides and example of how to generate the log and reference file:

# cd to test directory
cd build/fv3-jedi/test

# Run the application
mpirun -np 6 ../../bin/fv3jedi_forecast.x testinput/forecast.yaml forecast.log

# Generate the test reference file with grep 'Test     :' (five spaces followed by :)
grep 'Test     :' forecast.log > forecast.ref

For more on application testing, configuring numerical tolerances and other options see the documentation here: Application Testing . For more detailed instructions on the pieces of adding a test see the documentation here: Adding A Test .

Timing test

FV3-JEDI includes a timing test that runs as part of the Continuous integration. In this test the time each test takes to run is compared with some predetermined values. If a change is made that dramatically increases the time any of the tests take to run it will result in a failure. Reference timings for each test are located at e.g. test/testoutput/CTestCostData.txt.awsintel.test and the tests for which the run times are checked are at test/testinput/test_time.yaml.