tractor/tests/conftest.py

"""
``tractor`` testing!!
"""
from functools import partial
import sys
import subprocess
import os
import random
import signal
import platform
import time
from typing import (
    AsyncContextManager,
)

import pytest
import tractor
from tractor._testing import (
    examples_dir as examples_dir,
    tractor_test as tractor_test,
    expect_ctxc as expect_ctxc,
)

# TODO: include wtv plugin(s) we build in `._testing.pytest`?
pytest_plugins = ['pytester']

# 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='ERROR', 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",
    )

    parser.addoption(
        "--tpdb", "--debug-mode",
        action="store_true",
        dest='tractor_debug_mode',
        # default=False,
        help=(
            'Enable a flag that can be used by tests to to set the '
            '`debug_mode: bool` for engaging the internal '
            'multi-proc debugger sys.'
        ),
    )


def pytest_configure(config):
    backend = config.option.spawn_backend
    tractor._spawn.try_set_start_method(backend)


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


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


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


_ci_env: bool = os.environ.get('CI', False)


@pytest.fixture(scope='session')
def ci_env() -> bool:
    '''
    Detect CI envoirment.

    '''
    return _ci_env


# TODO: also move this to `._testing` for now?
# -[ ] possibly generalize and re-use for multi-tree spawning
#    along with the new stuff for multi-addrs in distribute_dis
#    branch?
#
# choose randomly at import time
_reg_addr: tuple[str, int] = (
    '127.0.0.1',
    random.randint(1000, 9999),
)


@pytest.fixture(scope='session')
def reg_addr() -> tuple[str, int]:

    # globally override the runtime to the per-test-session-dynamic
    # addr so that all tests never conflict with any other actor
    # tree using the default.
    from tractor import _root
    _root._default_lo_addrs = [_reg_addr]

    return _reg_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 = 'trio'

    # TODO: maybe just use the literal `._spawn.SpawnMethodKey`?
    assert spawn_backend in (
        'mp_spawn',
        'mp_forkserver',
        'trio',
    )

    # NOTE: used to be used to dyanmically parametrize tests for when
    # you just passed --spawn-backend=`mp` on the cli, but now we expect
    # that cli input to be manually specified, BUT, maybe we'll do
    # something like this again in the future?
    if 'start_method' in metafunc.fixturenames:
        metafunc.parametrize("start_method", [spawn_backend], scope='module')


# TODO: a way to let test scripts (like from `examples/`)
# guarantee they won't registry addr collide!
@pytest.fixture
def open_test_runtime(
    reg_addr: tuple,
) -> AsyncContextManager:
    return partial(
        tractor.open_nursery,
        registry_addrs=[reg_addr],
    )


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


# TODO: factor into @cm and move to `._testing`?
@pytest.fixture
def daemon(
    loglevel: str,
    testdir,
    reg_addr: tuple[str, int],
):
    '''
    Run a daemon root actor as a separate actor-process tree and
    "remote registrar" for discovery-protocol related tests.

    '''
    if loglevel in ('trace', 'debug'):
        # XXX: too much logging will lock up the subproc (smh)
        loglevel: str = 'info'

    code: str = (
            "import tractor; "
            "tractor.run_daemon([], registry_addrs={reg_addrs}, loglevel={ll})"
    ).format(
        reg_addrs=str([reg_addr]),
        ll="'{}'".format(loglevel) if loglevel else None,
    )
    cmd: list[str] = [
        sys.executable,
        '-c', code,
    ]
    kwargs = {}
    if platform.system() == 'Windows':
        # without this, tests hang on windows forever
        kwargs['creationflags'] = subprocess.CREATE_NEW_PROCESS_GROUP

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