chore: MockTiming - move impl to _pytest.timing

src/_pytest/timing.py

@@ -8,9 +8,45 @@ Fixture "mock_timing" also interacts with this module for pytest's own tests.
 
 from __future__ import annotations
 
+import dataclasses
+from datetime import datetime
 from time import perf_counter
 from time import sleep
 from time import time
+from typing import TYPE_CHECKING
+
+
+if TYPE_CHECKING:
+    from pytest import MonkeyPatch
+
+
+@dataclasses.dataclass
+class MockTiming:
+    """Mocks _pytest.timing with a known object that can be used to control timing in tests
+    deterministically.
+
+    pytest itself should always use functions from `_pytest.timing` instead of `time` directly.
+
+    This then allows us more control over time during testing, if testing code also
+    uses `_pytest.timing` functions.
+
+    Time is static, and only advances through `sleep` calls, thus tests might sleep over large
+    numbers and obtain accurate time() calls at the end, making tests reliable and instant."""
+
+    _current_time: float = datetime(2020, 5, 22, 14, 20, 50).timestamp()  # noqa: RUF009
+
+    def sleep(self, seconds: float) -> None:
+        self._current_time += seconds
+
+    def time(self) -> float:
+        return self._current_time
+
+    def patch(self, monkeypatch: MonkeyPatch) -> None:
+        from _pytest import timing  # noqa: PLW0406
+
+        monkeypatch.setattr(timing, "sleep", self.sleep)
+        monkeypatch.setattr(timing, "time", self.time)
+        monkeypatch.setattr(timing, "perf_counter", self.time)
 
 
 __all__ = ["perf_counter", "sleep", "time"]

testing/conftest.py

@@ -1,7 +1,6 @@
 # mypy: allow-untyped-defs
 from __future__ import annotations
 
-import dataclasses
 import re
 import sys
 from typing import Generator
@@ -226,24 +225,8 @@ def mock_timing(monkeypatch: MonkeyPatch):
     Time is static, and only advances through `sleep` calls, thus tests might sleep over large
     numbers and obtain accurate time() calls at the end, making tests reliable and instant.
     """
-
+    from _pytest.timing import MockTiming
-    @dataclasses.dataclass
-    class MockTiming:
-        _current_time: float = 1590150050.0
-
-        def sleep(self, seconds: float) -> None:
-            self._current_time += seconds
-
-        def time(self) -> float:
-            return self._current_time
-
-        def patch(self) -> None:
-            from _pytest import timing
-
-            monkeypatch.setattr(timing, "sleep", self.sleep)
-            monkeypatch.setattr(timing, "time", self.time)
-            monkeypatch.setattr(timing, "perf_counter", self.time)
 
     result = MockTiming()
-    result.patch()
+    result.patch(monkeypatch)
     return result