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Testing Helpers

chumicro_timing.testing provides FakeTicks, a hand-driven clock that only moves when you tell it to, plus a sleep_ms shim for host code that really does want to block. The module declares itself test support, so the deploy walker and the bundle builder drop it and it never lands on a microcontroller.

Usage with Rate and Deadline

The value objects take the current time as an explicit now_ms argument, so there is nothing to inject. Hand them FakeTicks.ticks_ms() at construction and on each poll, then use FakeTicks.advance() to move time forward:

from chumicro_timing import Rate
from chumicro_timing.testing import FakeTicks

def test_rate_fires_after_period() -> None:
    """Rate fires exactly when the period elapses."""
    fake = FakeTicks()
    rate = Rate(100, fake.ticks_ms())

    assert rate.due(fake.ticks_ms()) is False

    fake.advance(99)
    assert rate.due(fake.ticks_ms()) is False

    fake.advance(1)
    assert rate.due(fake.ticks_ms()) is True
    # The schedule has advanced, so polling again at the same time returns False.
    assert rate.due(fake.ticks_ms()) is False

A Deadline is driven the same way:

from chumicro_timing import Deadline
from chumicro_timing.testing import FakeTicks

def test_deadline_expires() -> None:
    """Deadline expires once the timeout elapses."""
    fake = FakeTicks()
    deadline = Deadline(100, fake.ticks_ms())

    assert deadline.expired(fake.ticks_ms()) is False
    assert deadline.remaining(fake.ticks_ms()) == 100

    fake.advance(100)
    assert deadline.expired(fake.ticks_ms()) is True
    assert deadline.remaining(fake.ticks_ms()) == 0

FakeTicks also answers sleep_ms(duration_ms) by advancing itself, so a Runner built with ticks=FakeTicks() idles instantly instead of stalling your test suite.

Using these fakes in your own tests

Your test suite imports the fake straight from the installed package, the same way this library's own tests do:

from chumicro_timing.testing import FakeTicks

Project convention: libraries that expose injectable services ship their own test fakes alongside the production code.

API Reference

chumicro_timing.testing

Test-support helpers: a sleep_ms shim and a hand-driven FakeTicks.

FakeTicks

Hand-driven ticks source; ticks_ms() only changes when advance() is called.

advance(amount_ms)

Bumps the current reading by amount_ms.

sleep_ms(duration_ms)

Advance the fake clock by duration_ms instead of sleeping for real.

ticks_ms()

Returns the current reading masked into the wrap-safe 29-bit range.

ticks_diff(end, start)

Returns the signed wrap-safe difference end - start.

ticks_add(ticks_val, delta)

Returns ticks_val + delta folded into the wrap-safe range.

sleep_ms(duration_ms)

Sleeps for duration_ms via time.sleep_ms when present, otherwise time.sleep in seconds.

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