pyodide/conftest.py

"""
Various common utilities for testing.
"""
import pathlib
import re
import sys

import pytest

ROOT_PATH = pathlib.Path(__file__).parents[0].resolve()
DIST_PATH = ROOT_PATH / "dist"

sys.path.append(str(ROOT_PATH / "pyodide-build"))
sys.path.append(str(ROOT_PATH / "src" / "py"))

import pytest_pyodide.runner
from pytest_pyodide.utils import package_is_built as _package_is_built

# There are a bunch of global objects that occasionally enter the hiwire cache
# but never leave. The refcount checks get angry about them if they aren't preloaded.
# We need to go through and touch them all once to keep everything okay.
pytest_pyodide.runner.INITIALIZE_SCRIPT = """
    pyodide.globals.get;
    pyodide._api.pyodide_code.eval_code;
    pyodide._api.pyodide_code.eval_code_async;
    pyodide._api.pyodide_code.find_imports;
    pyodide._api.pyodide_ffi.register_js_module;
    pyodide._api.pyodide_ffi.unregister_js_module;
    pyodide._api.importlib.invalidate_caches;
    pyodide._api.package_loader.unpack_buffer;
    pyodide._api.package_loader.get_dynlibs;
    pyodide._api.package_loader.sub_resource_hash;
    pyodide.runPython("");
    pyodide.pyimport("pyodide.ffi.wrappers").destroy();
"""


def pytest_addoption(parser):
    group = parser.getgroup("general")
    group.addoption(
        "--run-xfail",
        action="store_true",
        help="If provided, tests marked as xfail will be run",
    )
    group.addoption(
        "--skip-passed",
        action="store_true",
        help=(
            "If provided, tests that passed on the last run will be skipped. "
            "CAUTION: this will skip tests even if tests are modified"
        ),
    )


def maybe_skip_test(item, delayed=False):
    """If necessary skip test at the fixture level, to avoid
    loading the selenium_standalone fixture which takes a long time.
    """
    browsers = "|".join(["firefox", "chrome", "node"])
    is_common_test = str(item.fspath).endswith("test_packages_common.py")

    skip_msg = None
    # Testing a package. Skip the test if the package is not built.
    match = re.match(
        r".*/packages/(?P<name>[\w\-]+)/test_[\w\-]+\.py", str(item.parent.fspath)
    )
    if match and not is_common_test:
        package_name = match.group("name")
        if not package_is_built(package_name) and re.match(
            rf"test_[\w\-\.]+\[({browsers})[^\]]*\]", item.name
        ):
            skip_msg = f"package '{package_name}' is not built."

    # Common package import test. Skip it if the package is not built.
    if skip_msg is None and is_common_test and item.name.startswith("test_import"):
        match = re.match(rf"test_import\[({browsers})-(?P<name>[\w\-\.]+)\]", item.name)
        if match:
            package_name = match.group("name")
            if not package_is_built(package_name):
                # If the test is going to be skipped remove the
                # selenium_standalone as it takes a long time to initialize
                skip_msg = f"package '{package_name}' is not built."
        else:
            raise AssertionError(
                f"Couldn't parse package name from {item.name}. This should not happen!"
            )

    # TODO: also use this hook to skip doctests we cannot run (or run them
    # inside the selenium wrapper)

    if skip_msg is not None:
        if delayed:
            item.add_marker(pytest.mark.skip(reason=skip_msg))
        else:
            pytest.skip(skip_msg)


def pytest_configure(config):
    """Monkey patch the function cwd_relative_nodeid

    returns the description of a test for the short summary table. Monkey patch
    it to reduce the verbosity of the test names in the table.  This leaves
    enough room to see the information about the test failure in the summary.
    """
    global CONFIG

    old_cwd_relative_nodeid = config.cwd_relative_nodeid

    def cwd_relative_nodeid(*args):
        result = old_cwd_relative_nodeid(*args)
        result = result.replace("src/tests/", "")
        result = result.replace("packages/", "")
        result = result.replace("::test_", "::")
        return result

    config.cwd_relative_nodeid = cwd_relative_nodeid

    pytest.pyodide_dist_dir = config.getoption("--dist-dir")


def pytest_collection_modifyitems(config, items):
    """Called after collect is completed.
    Parameters
    ----------
    config : pytest config
    items : list of collected items
    """
    prev_test_result = {}
    if config.getoption("--skip-passed"):
        cache = config.cache
        prev_test_result = cache.get("cache/lasttestresult", {})

    for item in items:
        if prev_test_result.get(item.nodeid) in ("passed", "warnings", "skip_passed"):
            item.add_marker(pytest.mark.skip(reason="previously passed"))
            continue

        maybe_skip_test(item, delayed=True)


# Save test results to a cache
# Code adapted from: https://github.com/pytest-dev/pytest/blob/main/src/_pytest/pastebin.py
@pytest.hookimpl(trylast=True)
def pytest_terminal_summary(terminalreporter):
    tr = terminalreporter
    cache = tr.config.cache
    assert cache

    test_result = {}
    for status in tr.stats:
        if status in ("warnings", "deselected"):
            continue

        for test in tr.stats[status]:

            if test.when != "call":  # discard results from setup/teardown
                continue

            try:
                if test.longrepr and test.longrepr[2] in "previously passed":
                    test_result[test.nodeid] = "skip_passed"
                else:
                    test_result[test.nodeid] = test.outcome
            except Exception:
                pass

    cache.set("cache/lasttestresult", test_result)


@pytest.hookimpl(hookwrapper=True)
def pytest_runtest_call(item):
    """We want to run extra verification at the start and end of each test to
    check that we haven't leaked memory. According to pytest issue #5044, it's
    not possible to "Fail" a test from a fixture (no matter what you do, pytest
    sets the test status to "Error"). The approach suggested there is hook
    pytest_runtest_call as we do here. To get access to the selenium fixture, we
    imitate the definition of pytest_pyfunc_call:
    https://github.com/pytest-dev/pytest/blob/6.2.2/src/_pytest/python.py#L177

    Pytest issue #5044:
    https://github.com/pytest-dev/pytest/issues/5044
    """
    browser = None
    for fixture in item._fixtureinfo.argnames:
        if fixture.startswith("selenium"):
            browser = item.funcargs[fixture]
            break

    if not browser or not browser.pyodide_loaded:
        yield
        return

    trace_pyproxies = pytest.mark.skip_pyproxy_check.mark not in item.own_markers
    trace_hiwire_refs = (
        trace_pyproxies and pytest.mark.skip_refcount_check.mark not in item.own_markers
    )
    yield from extra_checks_test_wrapper(browser, trace_hiwire_refs, trace_pyproxies)


def extra_checks_test_wrapper(browser, trace_hiwire_refs, trace_pyproxies):
    """Extra conditions for test to pass:
    1. No explicit request for test to fail
    2. No leaked JsRefs
    3. No leaked PyProxys
    """
    browser.clear_force_test_fail()
    init_num_keys = browser.get_num_hiwire_keys()
    if trace_pyproxies:
        browser.enable_pyproxy_tracing()
        init_num_proxies = browser.get_num_proxies()
    a = yield
    try:
        # If these guys cause a crash because the test really screwed things up,
        # we override the error message with the better message returned by
        # a.result() in the finally block.
        browser.disable_pyproxy_tracing()
        browser.restore_state()
    finally:
        # if there was an error in the body of the test, flush it out by calling
        # get_result (we don't want to override the error message by raising a
        # different error here.)
        a.get_result()
    if browser.force_test_fail:
        raise Exception("Test failure explicitly requested but no error was raised.")
    if trace_pyproxies and trace_hiwire_refs:
        delta_proxies = browser.get_num_proxies() - init_num_proxies
        delta_keys = browser.get_num_hiwire_keys() - init_num_keys
        assert (delta_proxies, delta_keys) == (0, 0) or delta_keys < 0
    if trace_hiwire_refs:
        delta_keys = browser.get_num_hiwire_keys() - init_num_keys
        assert delta_keys <= 0


def package_is_built(package_name):
    return _package_is_built(package_name, pytest.pyodide_dist_dir)