Is there a way to control how pytest-xdist runs tests in parallel?
- by superselector
I have the following directory layout:
runner.py
lib/
tests/
      testsuite1/
                 testsuite1.py
      testsuite2/
                 testsuite2.py
      testsuite3/
                 testsuite3.py
      testsuite4/
                 testsuite4.py
The format of testsuite*.py modules is as follows:
import pytest 
class testsomething:
      def setup_class(self):
          ''' do some setup '''
          # Do some setup stuff here      
      def teardown_class(self):
          '''' do some teardown'''
          # Do some teardown stuff here
      def test1(self):
          # Do some test1 related stuff
      def test2(self):
          # Do some test2 related stuff
      ....
      ....
      ....
      def test40(self):
          # Do some test40 related stuff
if __name__=='__main()__'
   pytest.main(args=[os.path.abspath(__file__)])
The problem I have is that I would like to execute the 'testsuites' in parallel i.e. I want testsuite1, testsuite2, testsuite3 and testsuite4 to start execution in parallel but individual tests within the testsuites need to be executed serially.
When I use the 'xdist' plugin from py.test and kick off the tests using 'py.test -n 4', py.test is gathering all the tests and randomly load balancing the tests among 4 workers. This leads to the 'setup_class' method to be executed every time of each test within a 'testsuitex.py' module (which defeats my purpose. I want setup_class to be executed only once per class and tests executed serially there after).
Essentially what I want the execution to look like is:
worker1: executes all tests in testsuite1.py serially
worker2: executes all tests in testsuite2.py serially
worker3: executes all tests in testsuite3.py serially
worker4: executes all tests in testsuite4.py serially
while  worker1, worker2, worker3 and worker4  are all executed in parallel.
Is there a way to achieve this in 'pytest-xidst' framework?
The only option that I can think of is to kick off different processes to execute each test suite individually within runner.py:
def test_execute_func(testsuite_path):
    subprocess.process('py.test %s' % testsuite_path)
if __name__=='__main__':
   #Gather all the testsuite names
   for each testsuite:
       multiprocessing.Process(test_execute_func,(testsuite_path,))