tractor/tests/conftest.py

"""
``tractor`` testing!!
"""
import sys
import subprocess
import os
import random
import signal
import platform
import time

import pytest
import tractor

# export for tests
from tractor.testing import tractor_test  # noqa


pytest_plugins = ['pytester']
_arb_addr = '127.0.0.1', random.randint(1000, 9999)


# Sending signal.SIGINT on subprocess fails on windows. Use CTRL_* alternatives
if platform.system() == 'Windows':
    _KILL_SIGNAL = signal.CTRL_BREAK_EVENT
    _INT_SIGNAL = signal.CTRL_C_EVENT
    _INT_RETURN_CODE = 3221225786
    _PROC_SPAWN_WAIT = 2
else:
    _KILL_SIGNAL = signal.SIGKILL
    _INT_SIGNAL = signal.SIGINT
    _INT_RETURN_CODE = 1 if sys.version_info < (3, 8) else -signal.SIGINT.value
    _PROC_SPAWN_WAIT = 0.6 if sys.version_info < (3, 7) else 0.4


no_windows = pytest.mark.skipif(
    platform.system() == "Windows",
    reason="Test is unsupported on windows",
)


def pytest_addoption(parser):
    parser.addoption(
        "--ll", action="store", dest='loglevel',
        default=None, help="logging level to set when testing"
    )

    parser.addoption(
        "--spawn-backend", action="store", dest='spawn_backend',
        default='trio',
        help="Processing spawning backend to use for test run",
    )


def pytest_configure(config):
    backend = config.option.spawn_backend

    if backend == 'mp':
        tractor._spawn.try_set_start_method('spawn')
    elif backend == 'trio':
        tractor._spawn.try_set_start_method(backend)


@pytest.fixture(scope='session', autouse=True)
def loglevel(request):
    orig = tractor.log._default_loglevel
    level = tractor.log._default_loglevel = request.config.option.loglevel
    yield level
    tractor.log._default_loglevel = orig


@pytest.fixture(scope='session')
def spawn_backend(request):
    return request.config.option.spawn_backend


@pytest.fixture(scope='session')
def travis():
    """Bool determining whether running inside TravisCI.
    """
    return os.environ.get('TRAVIS', False)


@pytest.fixture(scope='session')
def arb_addr():
    return _arb_addr


def pytest_generate_tests(metafunc):
    spawn_backend = metafunc.config.option.spawn_backend
    if not spawn_backend:
        # XXX some weird windows bug with `pytest`?
        spawn_backend = 'mp'
    assert spawn_backend in ('mp', 'trio')

    if 'start_method' in metafunc.fixturenames:
        if spawn_backend == 'mp':
            from multiprocessing import get_all_start_methods
            methods = get_all_start_methods()
            if 'fork' in methods:
                # fork not available on windows, so check before
                # removing XXX: the fork method is in general
                # incompatible with trio's global scheduler state
                methods.remove('fork')
        elif spawn_backend == 'trio':
            methods = ['trio']

        metafunc.parametrize("start_method", methods, scope='module')


def sig_prog(proc, sig):
    "Kill the actor-process with ``sig``."
    proc.send_signal(sig)
    time.sleep(0.1)
    if not proc.poll():
        # TODO: why sometimes does SIGINT not work on teardown?
        # seems to happen only when trace logging enabled?
        proc.send_signal(_KILL_SIGNAL)
    ret = proc.wait()
    assert ret


@pytest.fixture
def daemon(loglevel, testdir, arb_addr):
    """Run a daemon actor as a "remote arbiter".
    """
    cmdargs = [
        sys.executable, '-c',
        "import tractor; tractor.run_daemon((), arbiter_addr={}, loglevel={})"
        .format(
            arb_addr,
            "'{}'".format(loglevel) if loglevel else None)
    ]
    kwargs = dict()
    if platform.system() == 'Windows':
        # without this, tests hang on windows forever
        kwargs['creationflags'] = subprocess.CREATE_NEW_PROCESS_GROUP

    proc = testdir.popen(
        cmdargs,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        **kwargs,
    )
    assert not proc.returncode
    time.sleep(_PROC_SPAWN_WAIT)
    yield proc
    sig_prog(proc, _INT_SIGNAL)