Remove the random state caching (#690)

Author: adamchainz

CHANGELOG.rst

@@ -2,6 +2,14 @@
 Changelog
 =========
 
+Unreleased
+----------
+
+* Removed the random state caching, which would grow without bound, leaking memory in long test runs.
+  The caching was added to slightly speed up re-using the same (final) seed, but since the final seed is now different for each test, it has no effect.
+
+  `PR #690 <https://github.com/pytest-dev/pytest-randomly/issues/687>`__.
+
 4.0.0 (2025-09-10)
 ------------------
 

src/pytest_randomly/__init__.py

@@ -140,38 +140,28 @@ def pytest_configure_node(self, node: Item) -> None:
         node.workerinput["randomly_seed"] = seed  # type: ignore [attr-defined]
 
 
-random_states: dict[int, tuple[Any, ...]] = {}
-np_random_states: dict[int, Any] = {}
-
-
 entrypoint_reseeds: list[Callable[[int], None]] | None = None
 
 
 def _reseed(config: Config, offset: int = 0) -> int:
     global entrypoint_reseeds
     seed: int = config.getoption("randomly_seed") + offset
-    if seed not in random_states:
-        random.seed(seed)
-        random_states[seed] = random.getstate()
-    else:
-        random.setstate(random_states[seed])
+
+    random.seed(seed)
+    random_state = random.getstate()
 
     if have_factory_boy:  # pragma: no branch
-        factory_set_random_state(random_states[seed])
+        factory_set_random_state(random_state)
 
     if have_faker:  # pragma: no branch
-        faker_random.setstate(random_states[seed])
+        faker_random.setstate(random_state)
 
     if have_model_bakery:  # pragma: no branch
-        baker_random.setstate(random_states[seed])
+        baker_random.setstate(random_state)
 
     if have_numpy:  # pragma: no branch
         numpy_seed = _truncate_seed_for_numpy(seed)
-        if numpy_seed not in np_random_states:
-            np_random.seed(numpy_seed)
-            np_random_states[numpy_seed] = np_random.get_state()
-        else:
-            np_random.set_state(np_random_states[numpy_seed])
+        np_random.seed(numpy_seed)
 
     if entrypoint_reseeds is None:
         eps = entry_points(group="pytest_randomly.random_seeder")