This document explains the practical steps for contributing code to atest.
Atest is essentially a wrapper around various test runners. Because of this division, your first step should be to identify the code involved with your change. This will help determine what tests you write and run. Note that the wrapper code is written in python, so we'll be referring to it as the "Python Code".
This code defines atest's command line interface. Its job is to translate user inputs into (1) build targets and (2) information needed for the test runner to run the test. It then invokes the appropriate test runner code to run the tests. As the tests are run it also parses the test runner's output into the output seen by the user. It uses Test Finder and Test Runner classes to do this work. If your contribution involves any of this functionality, this is the code you'll want to work on.
This is the code that actually runs the test. If your change involves how the test is actually run, you'll need to work with this code.
Each test runner will have a different workflow. Atest currently supports the following test runners:
The python code lives here: tools/tradefederation/core/atest/ (path relative to android repo root)
Test files go in the same directory as the file being tested. The test file should have the same name as the file it's testing, except it should have "_unittests" appended to the name. For example, tests for the logic in cli_translator.py go in the file cli_translator_unittests.py in the same directory.
Python tests are just python files executable by the Python interpreter. You can run ALL the python tests by executing this bash script in the atest root dir: ./run_atest_unittests.sh. Alternatively, you can directly execute any individual unittest file. However, you'll need to first add atest to your PYTHONPATH via entering in your terminal: PYTHONPATH=<atest_dir>:$PYTHONPATH.
All tests should be passing before you submit your change.
The TradeFed code lives here: tools/tradefederation/core/src/com/android/tradefed/ (path relative to android repo root).
The testtype/suite/AtestRunner.java is the most important file in the TradeFed Code. It defines the TradeFed API used by the Python Code, specifically by test_runners/atest_tf_test_runner.py. This is the file you'll want to edit if you need to make changes to the TradeFed code.
Tradefed test files live in a parallel /tests/ file tree here: tools/tradefederation/core/tests/src/com/android/tradefed/. A test file should have the same name as the file it's testing, except with the word "Test" appended to the end. For example, the tests for tools/tradefederation/core/src/com/android/tradefed/testtype/suite/AtestRunner.java can be found in tools/tradefederation/core/tests/src/com/android/tradefed/testtype/suite/AtestRunnerTest.java.
TradeFed itself is used to run the TradeFed unittests so you'll need to build TradeFed first. See the TradeFed README for information about setting up TradeFed. There are so many TradeFed tests that you'll probably want to first run the test file your code change affected individually. The command to run an individual test file is:
tradefed.sh run host -n --class <fully.qualified.ClassName>
Thus, to run all the tests in AtestRunnerTest.java, you'd enter:
tradefed.sh run host -n --class com.android.tradefed.testtype.suite.AtestRunnerTest
To run ALL the TradeFed unittests, enter: ./tools/tradefederation/core/tests/run_tradefed_tests.sh (from android repo root)
Before submitting code you should run all the TradeFed tests.
The VTS-Tradefed code lives here: test/vts/tools/vts-tradefed/ (path relative to android repo root)
You shouldn't need to edit vts-tradefed code, so there is no need to write vts-tradefed tests. Reach out to the vts team if you need information on their unittests.
Again, you shouldn't need to change vts-tradefed code.
The Robolectric code lives here: prebuilts/misc/common/robolectric/3.6.1/ (path relative to android repo root)
You shouldn't need to edit this code, so no need to write tests.
Again, you shouldn't need to edit this code, so no need to run test.