Add Trio support (#43)

* Add Trio support

Ref #42

* Add versionadded tags

* Add PR#

* Use consistently bare Trio URL

* Mention Trio in tutorial

* Be smart

CHANGELOG.md

@@ -15,6 +15,11 @@ You can find our backwards-compatibility policy [here](https://github.com/hynek/
 
 ## [Unreleased](https://github.com/hynek/stamina/compare/23.2.0...HEAD)
 
+### Added
+
+- [Trio](https://trio.readthedocs.io/) support!
+  [#43](https://github.com/hynek/stamina/pull/43)
+
 
 ## [23.2.0](https://github.com/hynek/stamina/compare/23.1.0...23.2.0) - 2023-10-30
 

README.md

@@ -19,7 +19,7 @@ It is the result of years of copy-pasting the same configuration over and over a
 - Retry only on certain exceptions.
 - Exponential **backoff** with **jitter** between retries.
 - Limit the number of retries **and** total time.
-- Automatic **async** support.
+- Automatic **async** support – including [Trio](https://trio.readthedocs.io/).
 - Preserve **type hints** of the decorated callable.
 - Flexible **instrumentation** with [Prometheus](https://github.com/prometheus/client_python), [*structlog*](https://www.structlog.org/), and standard library's `logging` support out-of-the-box.
 - Easy _global_ deactivation for testing.

docs/tutorial.md

@@ -49,7 +49,8 @@ for attempt in stamina.retry_context(on=httpx.HTTPError):
 
 ## Async
 
-Async works with the same functions and arguments -- you just have to use async functions and `async for`:
+Async works with the same functions and arguments for both [`asyncio`](https://docs.python.org/3/library/asyncio.html) and [Trio](https://trio.readthedocs.io/).
+Just use async functions and `async for`:
 
 ```python
 import datetime as dt

noxfile.py

@@ -69,7 +69,9 @@ def _get_pkg(posargs: list[str]) -> tuple[str, list[str]]:
 
 
 @nox.session(python=ALL_SUPPORTED)
-@nox.parametrize("opt_deps", [[], ["structlog", "prometheus-client"]])
+@nox.parametrize(
+    "opt_deps", [[], ["structlog", "prometheus-client"], ["trio"]]
+)
 def tests(session: nox.Session, opt_deps: list[str]) -> None:
     pkg, posargs = _get_pkg(session.posargs)
 

pyproject.toml

@@ -24,7 +24,7 @@ classifiers = [
 dependencies = ["tenacity", "typing-extensions; python_version<'3.10'"]
 
 [project.optional-dependencies]
-tests = ["pytest", "pytest-asyncio!=0.22.0"]
+tests = ["pytest", "anyio"]
 typing = ["mypy>=1.4"]
 docs = [
   "sphinx>=7.2.2",
@@ -41,6 +41,7 @@ dev = [
   "tomli; python_version<'3.11'",
   "structlog",
   "prometheus-client",
+  "trio",
 ]
 
 [project.urls]
@@ -100,7 +101,6 @@ addopts = ["-ra", "--strict-markers", "--strict-config"]
 testpaths = "tests"
 xfail_strict = true
 filterwarnings = ["once::Warning"]
-asyncio_mode = "auto"
 
 
 [tool.coverage.run]

src/stamina/_core.py

@@ -25,6 +25,29 @@
 else:
     from typing_extensions import ParamSpec
 
+try:
+    from sniffio import current_async_library
+except ImportError:  # pragma: no cover -- we always have sniffio in tests
+
+    def current_async_library() -> str:
+        return "asyncio"
+
+
+async def _smart_sleep(delay: float) -> None:
+    io = current_async_library()
+
+    if io == "asyncio":
+        import asyncio
+
+        await asyncio.sleep(delay)
+    elif io == "trio":
+        import trio
+
+        await trio.sleep(delay)
+    else:  # pragma: no cover
+        msg = f"Unknown async library: {io!r}"
+        raise RuntimeError(msg)
+
 
 T = TypeVar("T")
 P = ParamSpec("P")
@@ -46,6 +69,7 @@ def retry_context(
     Arguments have the same meaning as for :func:`stamina.retry`.
 
     .. versionadded:: 23.1.0
+    .. versionadded:: 23.3.0 `Trio <https://trio.readthedocs.io/>`_ support.
     """
 
     return _RetryContextIterator.from_params(
@@ -113,7 +137,9 @@ class _LazyNoAsyncRetry:
     __slots__ = ()
 
     def __aiter__(self) -> _t.AsyncRetrying:
-        return _t.AsyncRetrying(reraise=True, stop=_STOP_NO_RETRY).__aiter__()
+        return _t.AsyncRetrying(
+            reraise=True, stop=_STOP_NO_RETRY, sleep=_smart_sleep
+        ).__aiter__()
 
 
 _LAZY_NO_ASYNC_RETRY = _LazyNoAsyncRetry()
@@ -197,6 +223,7 @@ def __iter__(self) -> Iterator[Attempt]:
     def __aiter__(self) -> AsyncIterator[Attempt]:
         if CONFIG.is_active:
             self._t_a_retrying = _t.AsyncRetrying(
+                sleep=_smart_sleep,
                 before_sleep=_make_before_sleep(
                     self._name, CONFIG, self._args, self._kw
                 ),
@@ -323,6 +350,8 @@ def retry(
 
        All time-related parameters can now be specified as a
        :class:`datetime.timedelta`.
+
+    .. versionadded:: 23.3.0 `Trio <https://trio.readthedocs.io/>`_ support.
     """
     retry_ctx = _RetryContextIterator.from_params(
         on=on,

tests/conftest.py

@@ -2,6 +2,8 @@
 #
 # SPDX-License-Identifier: MIT
 
+import importlib.util
+
 import pytest
 
 import stamina._config
@@ -14,3 +16,13 @@ def _reset_config():
     """
     stamina.set_active(True)
     stamina.instrumentation.set_on_retry_hooks(None)
+
+
+BACKENDS = [pytest.param(("asyncio", {}), id="asyncio")]
+if importlib.util.find_spec("trio"):
+    BACKENDS += [pytest.param(("trio", {}), id="trio")]
+
+
+@pytest.fixture(params=BACKENDS)
+def anyio_backend(request):
+    return request.param

tests/test_async.py

@@ -9,6 +9,9 @@
 import stamina
 
 
+pytestmark = pytest.mark.anyio
+
+
 @pytest.mark.parametrize("attempts", [None, 1])
 @pytest.mark.parametrize("timeout", [None, 1, dt.timedelta(days=1)])
 @pytest.mark.parametrize("duration", [1, dt.timedelta(days=1)])

tests/test_instrumentation.py

@@ -135,6 +135,7 @@ def f():
             ("stamina", 30, "stamina.retry_scheduled")
         ] == caplog.record_tuples
 
+    @pytest.mark.anyio()
     async def test_async(self, caplog):
         """
         Async retries are logged.

tests/test_structlog.py

@@ -47,6 +47,7 @@ def f():
     ] == log_output
 
 
+@pytest.mark.anyio()
 async def test_decorator_async(log_output):
     """
     Retries decorators log correct name / arguments.
@@ -97,6 +98,7 @@ def test_context_sync(log_output):
     ] == log_output
 
 
+@pytest.mark.anyio()
 async def test_context_async(log_output):
     """
     Retries context blocks log correct name / arguments.