Executors

Here are informations about how the tests are executed and how you can extend this behaviour.

About

An Executor is a class that runs the tests and it must implement the ITestExecutor interface.

The default executor

The default test executor runs test in sequential order in a single thread. You don’t have to do anything to use this executor.

Parallel executor

The parallel executor run the tests in parallel. In order to use this executor, you have to add in your trial.json:

  "executor": "parallel"

or pass -e parallel on the command line. The tests run on a pool of maxThreads worker threads that are reused from one test to the next. 0, the default, uses as many threads as your CPU can run at once.

This executor is experimental. Keep in mind that D module variables are thread local, so a test that reads state set up by another thread sees its own empty copy. Tests that rely on that kind of shared state can fail here while they pass with the default executor.

Process executor

This executor runs each test in a separate process, by starting the test executable again with exact filters (-s "=<suite>" -t "=<test>") so that each child runs exactly one test. A crash, like a segmentation fault, then fails only that test instead of stopping the whole run. It does not run the processes in parallel.

To use this executor, add in yout trial.json:

  "executor": "process"

or pass -e process on the command line.

Extending

In order to write your executor, your class must implement the ITestExecutor method.

If you want to use your custom test executor, you can replace the default one by adding it to the LifeCycleListeners:

static this() {
    LifeCycleListeners.instance.add(new MyCustomExecutor);
}

Be aware that by adding a test executor, you will replace the previous one, since it does not make sense to have more than one executor at a time.