moving to scripts

asq-env/lib/python3.9/site-packages/trio/tests/test_timeouts.py

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+import outcome
+import pytest
+import time
+
+from .._core.tests.tutil import slow
+from .. import _core
+from ..testing import assert_checkpoints
+from .._timeouts import *
+
+
+async def check_takes_about(f, expected_dur):
+    start = time.perf_counter()
+    result = await outcome.acapture(f)
+    dur = time.perf_counter() - start
+    print(dur / expected_dur)
+    # 1.5 is an arbitrary fudge factor because there's always some delay
+    # between when we become eligible to wake up and when we actually do. We
+    # used to sleep for 0.05, and regularly observed overruns of 1.6x on
+    # Appveyor, and then started seeing overruns of 2.3x on Travis's macOS, so
+    # now we bumped up the sleep to 1 second, marked the tests as slow, and
+    # hopefully now the proportional error will be less huge.
+    #
+    # We also also for durations that are a hair shorter than expected. For
+    # example, here's a run on Windows where a 1.0 second sleep was measured
+    # to take 0.9999999999999858 seconds:
+    #   https://ci.appveyor.com/project/njsmith/trio/build/1.0.768/job/3lbdyxl63q3h9s21
+    # I believe that what happened here is that Windows's low clock resolution
+    # meant that our calls to time.monotonic() returned exactly the same
+    # values as the calls inside the actual run loop, but the two subtractions
+    # returned slightly different values because the run loop's clock adds a
+    # random floating point offset to both times, which should cancel out, but
+    # lol floating point we got slightly different rounding errors. (That
+    # value above is exactly 128 ULPs below 1.0, which would make sense if it
+    # started as a 1 ULP error at a different dynamic range.)
+    assert (1 - 1e-8) <= (dur / expected_dur) < 1.5
+    return result.unwrap()
+
+
+# How long to (attempt to) sleep for when testing. Smaller numbers make the
+# test suite go faster.
+TARGET = 1.0
+
+
+@slow
+async def test_sleep():
+    async def sleep_1():
+        await sleep_until(_core.current_time() + TARGET)
+
+    await check_takes_about(sleep_1, TARGET)
+
+    async def sleep_2():
+        await sleep(TARGET)
+
+    await check_takes_about(sleep_2, TARGET)
+
+    with pytest.raises(ValueError):
+        await sleep(-1)
+
+    with assert_checkpoints():
+        await sleep(0)
+    # This also serves as a test of the trivial move_on_at
+    with move_on_at(_core.current_time()):
+        with pytest.raises(_core.Cancelled):
+            await sleep(0)
+
+
+@slow
+async def test_move_on_after():
+    with pytest.raises(ValueError):
+        with move_on_after(-1):
+            pass  # pragma: no cover
+
+    async def sleep_3():
+        with move_on_after(TARGET):
+            await sleep(100)
+
+    await check_takes_about(sleep_3, TARGET)
+
+
+@slow
+async def test_fail():
+    async def sleep_4():
+        with fail_at(_core.current_time() + TARGET):
+            await sleep(100)
+
+    with pytest.raises(TooSlowError):
+        await check_takes_about(sleep_4, TARGET)
+
+    with fail_at(_core.current_time() + 100):
+        await sleep(0)
+
+    async def sleep_5():
+        with fail_after(TARGET):
+            await sleep(100)
+
+    with pytest.raises(TooSlowError):
+        await check_takes_about(sleep_5, TARGET)
+
+    with fail_after(100):
+        await sleep(0)
+
+    with pytest.raises(ValueError):
+        with fail_after(-1):
+            pass  # pragma: no cover