fix: Avoid overwriting local contexts with retry decorator (#479)

* Avoid overwriting local contexts with retry decorator

* Add reno release note

Author: hasier

releasenotes/notes/fix-local-context-overwrite-94190ba06a481631.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Avoid overwriting local contexts when applying the retry decorator.

tenacity/__init__.py

@@ -329,13 +329,19 @@ def wraps(self, f: WrappedFn) -> WrappedFn:
             f, functools.WRAPPER_ASSIGNMENTS + ("__defaults__", "__kwdefaults__")
         )
         def wrapped_f(*args: t.Any, **kw: t.Any) -> t.Any:
-            return self(f, *args, **kw)
+            # Always create a copy to prevent overwriting the local contexts when
+            # calling the same wrapped functions multiple times in the same stack
+            copy = self.copy()
+            wrapped_f.statistics = copy.statistics  # type: ignore[attr-defined]
+            return copy(f, *args, **kw)
 
         def retry_with(*args: t.Any, **kwargs: t.Any) -> WrappedFn:
             return self.copy(*args, **kwargs).wraps(f)
 
-        wrapped_f.retry = self  # type: ignore[attr-defined]
+        # Preserve attributes
+        wrapped_f.retry = wrapped_f  # type: ignore[attr-defined]
         wrapped_f.retry_with = retry_with  # type: ignore[attr-defined]
+        wrapped_f.statistics = {}  # type: ignore[attr-defined]
 
         return wrapped_f  # type: ignore[return-value]
 

tenacity/asyncio/__init__.py

@@ -175,18 +175,23 @@ async def __anext__(self) -> AttemptManager:
                 raise StopAsyncIteration
 
     def wraps(self, fn: WrappedFn) -> WrappedFn:
-        fn = super().wraps(fn)
+        wrapped = super().wraps(fn)
         # Ensure wrapper is recognized as a coroutine function.
 
         @functools.wraps(
             fn, functools.WRAPPER_ASSIGNMENTS + ("__defaults__", "__kwdefaults__")
         )
         async def async_wrapped(*args: t.Any, **kwargs: t.Any) -> t.Any:
-            return await fn(*args, **kwargs)
+            # Always create a copy to prevent overwriting the local contexts when
+            # calling the same wrapped functions multiple times in the same stack
+            copy = self.copy()
+            async_wrapped.statistics = copy.statistics  # type: ignore[attr-defined]
+            return await copy(fn, *args, **kwargs)
 
         # Preserve attributes
-        async_wrapped.retry = fn.retry  # type: ignore[attr-defined]
-        async_wrapped.retry_with = fn.retry_with  # type: ignore[attr-defined]
+        async_wrapped.retry = async_wrapped  # type: ignore[attr-defined]
+        async_wrapped.retry_with = wrapped.retry_with  # type: ignore[attr-defined]
+        async_wrapped.statistics = {}  # type: ignore[attr-defined]
 
         return async_wrapped  # type: ignore[return-value]
 

tests/test_issue_478.py

@@ -0,0 +1,118 @@
+import asyncio
+import typing
+import unittest
+
+from functools import wraps
+
+from tenacity import RetryCallState, retry
+
+
+def asynctest(
+    callable_: typing.Callable[..., typing.Any],
+) -> typing.Callable[..., typing.Any]:
+    @wraps(callable_)
+    def wrapper(*a: typing.Any, **kw: typing.Any) -> typing.Any:
+        loop = asyncio.get_event_loop()
+        return loop.run_until_complete(callable_(*a, **kw))
+
+    return wrapper
+
+
+MAX_RETRY_FIX_ATTEMPTS = 2
+
+
+class TestIssue478(unittest.TestCase):
+    def test_issue(self) -> None:
+        results = []
+
+        def do_retry(retry_state: RetryCallState) -> bool:
+            outcome = retry_state.outcome
+            assert outcome
+            ex = outcome.exception()
+            _subject_: str = retry_state.args[0]
+
+            if _subject_ == "Fix":  # no retry on fix failure
+                return False
+
+            if retry_state.attempt_number >= MAX_RETRY_FIX_ATTEMPTS:
+                return False
+
+            if ex:
+                do_fix_work()
+                return True
+
+            return False
+
+        @retry(reraise=True, retry=do_retry)
+        def _do_work(subject: str) -> None:
+            if subject == "Error":
+                results.append(f"{subject} is not working")
+                raise Exception(f"{subject} is not working")
+            results.append(f"{subject} is working")
+
+        def do_any_work(subject: str) -> None:
+            _do_work(subject)
+
+        def do_fix_work() -> None:
+            _do_work("Fix")
+
+        try:
+            do_any_work("Error")
+        except Exception as exc:
+            assert str(exc) == "Error is not working"
+        else:
+            assert False, "No exception caught"
+
+        assert results == [
+            "Error is not working",
+            "Fix is working",
+            "Error is not working",
+        ]
+
+    @asynctest
+    async def test_async(self) -> None:
+        results = []
+
+        async def do_retry(retry_state: RetryCallState) -> bool:
+            outcome = retry_state.outcome
+            assert outcome
+            ex = outcome.exception()
+            _subject_: str = retry_state.args[0]
+
+            if _subject_ == "Fix":  # no retry on fix failure
+                return False
+
+            if retry_state.attempt_number >= MAX_RETRY_FIX_ATTEMPTS:
+                return False
+
+            if ex:
+                await do_fix_work()
+                return True
+
+            return False
+
+        @retry(reraise=True, retry=do_retry)
+        async def _do_work(subject: str) -> None:
+            if subject == "Error":
+                results.append(f"{subject} is not working")
+                raise Exception(f"{subject} is not working")
+            results.append(f"{subject} is working")
+
+        async def do_any_work(subject: str) -> None:
+            await _do_work(subject)
+
+        async def do_fix_work() -> None:
+            await _do_work("Fix")
+
+        try:
+            await do_any_work("Error")
+        except Exception as exc:
+            assert str(exc) == "Error is not working"
+        else:
+            assert False, "No exception caught"
+
+        assert results == [
+            "Error is not working",
+            "Fix is working",
+            "Error is not working",
+        ]