Developing new classes for LAVA V2¶
Test with simple scripts¶
Prove that your idea of a test job actually works on the hardware
Build the requirements of automation into your tests
Consider the needs of a serial console.
Think about all the steps, including temporary paths
Write a simple script that covers all the steps.
Start with new classes¶
For a completely new strategy, new classes are often best going into new files.
Follow the example of existing files but concentrate on just the
functions and imports at this stage. Adding the summary and description
elements should help you identify how to divide the work between the classes.
Add support files for unit tests¶
Create a device configuration YAML file with the help of the Online YAML parser using examples of existing files.
Create a job submission YAML file, again with the parser and existing examples.
At each stage, consider which elements of the job and device configuration may need to be overridden by test writers and instance admins.
Add unit tests¶
It may seem strange to add one or more unit test files at this stage but it helps write the validate functions which come up next. Adapt an existing Factory class to load the device configuration file and sample job file and then create a Job. In the test cases, inspect the pipeline created from these YAML files. Whenever the validate or populate functions are modified, add checks to the unit test that the new data exists in the correct type and content. Re-run the unit test each time to spot regressions.
Run all the unit tests¶
There are a number of unit tests which parse all jobs and devices in the test
directories, so ensure that the new additions do not interfere with the
existing tests. This is the basis of what needs to go into the
function of the Strategy class and into the job and device YAML. Make sure that
there is sufficient differentiation between the new files and the existing
files without causing duplication.
Incorporate the test script into the classes¶
If the new classes are properly aligned with the workload of the test job, the sections of the test script will fall naturally into the classes in the same sequence.
Handle all of the static data from
validatefunction. It is often useful to assemble some these parameters into member variables, checking that the final form is correct in the test case.
validateinstead of raising an exception of allowing calls within
validatefrom raising unhandled exceptions. If
validateshould not continue executing after a particular error, always ensure that an error is set before returning from
Test that all of the parameters appear in the class in the correct type and with the correct content after running
job.validate(). The simplest way to do this is to inspect the
job.pipeline.actionsusing a list comprehension based on the action
Handle only dynamic data in the
runfunction (which does not need to be completed at this stage).
Separate constants from parameters.
utils.constantswill provide a way for instance admins to make changes. If there is a chance that either a different device-type or a different test job plan, then add the default to the job or device file and fetch the value in the parameters. Ensure that
validateshows that the correct value is available.
Use existing classes where the support
just works, e.g. by adding
Check the new classes¶
pylint can be annoying but it is also useful - providing that some of the
warnings and errors are disabled. Check similar files but do be cautious about
disabling lots of warnings in the early stages. Pay particular attention to
missing imports, unused variables, unused imports, and invalid names. Logging
not lazy is less relevant, overall, in the LAVA codebase - there are situations
where lazy logging results in the wrong values being entered into the logs.
pep8 is essential - no reviews will be accepted if there
pep8 errors beyond
line-too-long (E501). This is the first check
./ci-run (which must also pass).
From this point, standard code development takes over. To get the code accepted, some guidelines must be followed:
./ci-runmust complete without errors
Every set of new classes should have some unit tests.
Every new Strategy must have new unit tests.
Part of the review will be whether the unit tests have sufficient coverage of the new code and possible side-effects with existing code.