`the sweep tolerates a staging path that is not a directory` failed once on run
33069641674, against 468 tests that pass on this machine including under
`--rerun-tasks`:
java.io.FileNotFoundException at OutputPublisherStagingTest.kt:112
468 tests completed, 1 failed
Line 112 was `writeBytes` immediately after `deleteRecursively()`.
`FileOutputStream` answers `FileNotFoundException` for an existing directory, so
something had recreated the path inside that window. That something is
`LibreMediaConverterApp.onCreate`, which ends with
appScope.launch { OutputPublisher(...).sweepStaging() }
on `Dispatchers.IO`, and `sweepStaging` reads `stagingDir`, whose getter calls
`mkdirs()`. Robolectric builds the application for every test that asks for one,
so that background `mkdirs()` is in flight across the whole suite on a thread the
paused main looper does not control and no test awaits.
Retrying closes the window rather than narrowing it, because the race is not
symmetric: `mkdirs()` fails on an existing regular file, so the invariant only has
to survive being *established*. Once a write lands, nothing in the suite can turn
this path back into a directory -- which is also why the new assertion that the
sweep left a file behind is worth making.
The `check()` matters as much as the loop. The next failure here should say
"something recreated conversions/ as a directory", not `FileNotFoundException at
line 112` -- that is the difference between a flake someone reads and a flake
someone re-runs.
The wider problem is #159 and is deliberately not fixed here: `AppStartSweepTest`,
`JobSnapshotsTest` and `SpaceArithmeticTest` all name the same path, and the real
answer is an injectable scope rather than a retry loop in every staging test.
#159's done-when is that this loop can be deleted.
Mutation: `listFiles() ?: return` -> `listFiles()!!` reddens exactly this test.
Gate green: assembleDebug, testDebugUnitTest, compileDebugAndroidTestKotlin,
ktlintCheck, detekt, lintDebug.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
JMR-devandClaude Opus 5
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