pytest_plugin.py

import asyncio
import contextlib
import inspect
import warnings
from typing import Any, Awaitable, Callable, Dict, Generator, Optional, Type, Union

import pytest

from aiohttp.web import Application

from .test_utils import (
    BaseTestServer,
    RawTestServer,
    TestClient,
    TestServer,
    loop_context,
    setup_test_loop,
    teardown_test_loop,
    unused_port as _unused_port,
)

try:
    import uvloop
except ImportError:  # pragma: no cover
    uvloop = None

try:
    import tokio
except ImportError:  # pragma: no cover
    tokio = None

AiohttpClient = Callable[[Union[Application, BaseTestServer]], Awaitable[TestClient]]


def pytest_addoption(parser):  # type: ignore[no-untyped-def]
    parser.addoption(
        "--aiohttp-fast",
        action="store_true",
        default=False,
        help="run tests faster by disabling extra checks",
    )
    parser.addoption(
        "--aiohttp-loop",
        action="store",
        default="pyloop",
        help="run tests with specific loop: pyloop, uvloop, tokio or all",
    )
    parser.addoption(
        "--aiohttp-enable-loop-debug",
        action="store_true",
        default=False,
        help="enable event loop debug mode",
    )


def pytest_fixture_setup(fixturedef):  # type: ignore[no-untyped-def]
    """Set up pytest fixture.

    Allow fixtures to be coroutines. Run coroutine fixtures in an event loop.
    """
    func = fixturedef.func

    if inspect.isasyncgenfunction(func):
        # async generator fixture
        is_async_gen = True
    elif asyncio.iscoroutinefunction(func):
        # regular async fixture
        is_async_gen = False
    else:
        # not an async fixture, nothing to do
        return

    strip_request = False
    if "request" not in fixturedef.argnames:
        fixturedef.argnames += ("request",)
        strip_request = True

    def wrapper(*args, **kwargs):  # type: ignore[no-untyped-def]
        request = kwargs["request"]
        if strip_request:
            del kwargs["request"]

        # if neither the fixture nor the test use the 'loop' fixture,
        # 'getfixturevalue' will fail because the test is not parameterized
        # (this can be removed someday if 'loop' is no longer parameterized)
        if "loop" not in request.fixturenames:
            raise Exception(
                "Asynchronous fixtures must depend on the 'loop' fixture or "
                "be used in tests depending from it."
            )

        _loop = request.getfixturevalue("loop")

        if is_async_gen:
            # for async generators, we need to advance the generator once,
            # then advance it again in a finalizer
            gen = func(*args, **kwargs)

            def finalizer():  # type: ignore[no-untyped-def]
                try:
                    return _loop.run_until_complete(gen.__anext__())
                except StopAsyncIteration:
                    pass

            request.addfinalizer(finalizer)
            return _loop.run_until_complete(gen.__anext__())
        else:
            return _loop.run_until_complete(func(*args, **kwargs))

    fixturedef.func = wrapper


@pytest.fixture
def fast(request):  # type: ignore[no-untyped-def]
    """--fast config option"""
    return request.config.getoption("--aiohttp-fast")


@pytest.fixture
def loop_debug(request):  # type: ignore[no-untyped-def]
    """--enable-loop-debug config option"""
    return request.config.getoption("--aiohttp-enable-loop-debug")


@contextlib.contextmanager
def _runtime_warning_context():  # type: ignore[no-untyped-def]
    """Context manager which checks for RuntimeWarnings.

    This exists specifically to
    avoid "coroutine 'X' was never awaited" warnings being missed.

    If RuntimeWarnings occur in the context a RuntimeError is raised.
    """
    with warnings.catch_warnings(record=True) as _warnings:
        yield
        rw = [
            "{w.filename}:{w.lineno}:{w.message}".format(w=w)
            for w in _warnings
            if w.category == RuntimeWarning
        ]
        if rw:
            raise RuntimeError(
                "{} Runtime Warning{},\n{}".format(
                    len(rw), "" if len(rw) == 1 else "s", "\n".join(rw)
                )
            )

    # Propagate warnings to pytest
    for msg in _warnings:
        warnings.showwarning(
            msg.message, msg.category, msg.filename, msg.lineno, msg.file, msg.line
        )


@contextlib.contextmanager
def _passthrough_loop_context(loop, fast=False):  # type: ignore[no-untyped-def]
    """Passthrough loop context.

    Sets up and tears down a loop unless one is passed in via the loop
    argument when it's passed straight through.
    """
    if loop:
        # loop already exists, pass it straight through
        yield loop
    else:
        # this shadows loop_context's standard behavior
        loop = setup_test_loop()
        yield loop
        teardown_test_loop(loop, fast=fast)


def pytest_pycollect_makeitem(collector, name, obj):  # type: ignore[no-untyped-def]
    """Fix pytest collecting for coroutines."""
    if collector.funcnamefilter(name) and asyncio.iscoroutinefunction(obj):
        return list(collector._genfunctions(name, obj))


def pytest_pyfunc_call(pyfuncitem):  # type: ignore[no-untyped-def]
    """Run coroutines in an event loop instead of a normal function call."""
    fast = pyfuncitem.config.getoption("--aiohttp-fast")
    if asyncio.iscoroutinefunction(pyfuncitem.function):
        existing_loop = pyfuncitem.funcargs.get(
            "proactor_loop"
        ) or pyfuncitem.funcargs.get("loop", None)
        with _runtime_warning_context():
            with _passthrough_loop_context(existing_loop, fast=fast) as _loop:
                testargs = {
                    arg: pyfuncitem.funcargs[arg]
                    for arg in pyfuncitem._fixtureinfo.argnames
                }
                _loop.run_until_complete(pyfuncitem.obj(**testargs))

        return True


def pytest_generate_tests(metafunc):  # type: ignore[no-untyped-def]
    if "loop_factory" not in metafunc.fixturenames:
        return

    loops = metafunc.config.option.aiohttp_loop
    avail_factories = {"pyloop": asyncio.DefaultEventLoopPolicy}

    if uvloop is not None:  # pragma: no cover
        avail_factories["uvloop"] = uvloop.EventLoopPolicy

    if tokio is not None:  # pragma: no cover
        avail_factories["tokio"] = tokio.EventLoopPolicy

    if loops == "all":
        loops = "pyloop,uvloop?,tokio?"

    factories = {}  # type: ignore[var-annotated]
    for name in loops.split(","):
        required = not name.endswith("?")
        name = name.strip(" ?")
        if name not in avail_factories:  # pragma: no cover
            if required:
                raise ValueError(
                    "Unknown loop '%s', available loops: %s"
                    % (name, list(factories.keys()))
                )
            else:
                continue
        factories[name] = avail_factories[name]
    metafunc.parametrize(
        "loop_factory", list(factories.values()), ids=list(factories.keys())
    )


@pytest.fixture
def loop(loop_factory, fast, loop_debug):  # type: ignore[no-untyped-def]
    """Return an instance of the event loop."""
    policy = loop_factory()
    asyncio.set_event_loop_policy(policy)
    with loop_context(fast=fast) as _loop:
        if loop_debug:
            _loop.set_debug(True)  # pragma: no cover
        asyncio.set_event_loop(_loop)
        yield _loop


@pytest.fixture
def proactor_loop():  # type: ignore[no-untyped-def]
    policy = asyncio.WindowsProactorEventLoopPolicy()  # type: ignore[attr-defined]
    asyncio.set_event_loop_policy(policy)

    with loop_context(policy.new_event_loop) as _loop:
        asyncio.set_event_loop(_loop)
        yield _loop


@pytest.fixture
def aiohttp_unused_port():  # type: ignore[no-untyped-def]
    """Return a port that is unused on the current host."""
    return _unused_port


@pytest.fixture
def aiohttp_server(loop):  # type: ignore[no-untyped-def]
    """Factory to create a TestServer instance, given an app.

    aiohttp_server(app, **kwargs)
    """
    servers = []

    async def go(app, *, port=None, **kwargs):  # type: ignore[no-untyped-def]
        server = TestServer(app, port=port)
        await server.start_server(**kwargs)
        servers.append(server)
        return server

    yield go

    async def finalize() -> None:
        while servers:
            await servers.pop().close()

    loop.run_until_complete(finalize())


@pytest.fixture
def aiohttp_raw_server(loop):  # type: ignore[no-untyped-def]
    """Factory to create a RawTestServer instance, given a web handler.

    aiohttp_raw_server(handler, **kwargs)
    """
    servers = []

    async def go(handler, *, port=None, **kwargs):  # type: ignore[no-untyped-def]
        server = RawTestServer(handler, port=port)
        await server.start_server(**kwargs)
        servers.append(server)
        return server

    yield go

    async def finalize() -> None:
        while servers:
            await servers.pop().close()

    loop.run_until_complete(finalize())


@pytest.fixture
def aiohttp_client_cls() -> Type[TestClient]:
    """
    Client class to use in ``aiohttp_client`` factory.

    Use it for passing custom ``TestClient`` implementations.

    Example::

       class MyClient(TestClient):
           async def login(self, *, user, pw):
               payload = {"username": user, "password": pw}
               return await self.post("/login", json=payload)

       @pytest.fixture
       def aiohttp_client_cls():
           return MyClient

       def test_login(aiohttp_client):
           app = web.Application()
           client = await aiohttp_client(app)
           await client.login(user="admin", pw="s3cr3t")

    """
    return TestClient


@pytest.fixture
def aiohttp_client(
    loop: asyncio.AbstractEventLoop, aiohttp_client_cls: Type[TestClient]
) -> Generator[AiohttpClient, None, None]:
    """Factory to create a TestClient instance.

    aiohttp_client(app, **kwargs)
    aiohttp_client(server, **kwargs)
    aiohttp_client(raw_server, **kwargs)
    """
    clients = []

    async def go(
        __param: Union[Application, BaseTestServer],
        *,
        server_kwargs: Optional[Dict[str, Any]] = None,
        **kwargs: Any
    ) -> TestClient:
        if isinstance(__param, Application):
            server_kwargs = server_kwargs or {}
            server = TestServer(__param, **server_kwargs)
            client = aiohttp_client_cls(server, **kwargs)
        elif isinstance(__param, BaseTestServer):
            client = aiohttp_client_cls(__param, **kwargs)
        else:
            raise ValueError("Unknown argument type: %r" % type(__param))

        await client.start_server()
        clients.append(client)
        return client

    yield go

    async def finalize() -> None:
        while clients:
            await clients.pop().close()

    loop.run_until_complete(finalize())