Robolectric builds an Application per test class that asks for one, and each
onCreate launched a staging sweep on Dispatchers.IO over the shared
<cacheDir>/conversions/. Nothing joined them, so a test asserting about a staged
file was racing every sweep the classes before it had left in flight (#159).
It was CI-only until wave 4 added ten Robolectric classes, at which point
OutputPublisherStagingTest started failing locally too.
LibreMediaConverterApp gains a protected open sweepScope and publishes the Job
onCreate started; the JVM suite substitutes TestLibreMediaConverterApp, whose
scope is Dispatchers.Unconfined so the sweep -- a plain function that never
suspends -- runs to completion inline. The SupervisorJob is kept so this differs
from production in the dispatcher alone.
Suite-wide rather than per-test: 27 of the 58 Robolectric classes touch that
directory, so opt-in was not a real option.
It costs one assertion, knowingly. AppStartSweepTest opened by asserting that
the manifest's android:name is what Robolectric instantiated. An application=
override replaces the manifest rather than being checked against it, and
applicationInfo.className reports the override too, so that claim is now
unobservable from this source set and a rewritten version would assert the
override against itself. The manifest link is device-only; the cast in setUp
still catches the test app ceasing to extend the real one.
AppStartSweepTest also joins the published Job instead of polling for ten
seconds -- a poll cannot tell "swept" from "not started yet" -- and gains a test
pinning that the sweep is complete when onCreate returns, which is the property
the substitution exists for and the only place it is checked.
Verified by mutation rather than by repetition. Putting the test app back on
Dispatchers.IO reddens that test 5 times out of 5, while running the whole suite
six times per arm caught nothing either way: at the rate #159 was observed at, a
clean six-run arm is roughly a coin flip, so the comparison was underpowered and
is not offered as evidence.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
JMR-devandClaude Opus 5
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