The stateful outer composables hand `ConverterScreenContent` and
`JoinScreenContent` a list of `viewModel::` references. No test in the suite had
ever seen that list: the content tests build their own `ConverterActions`, so
they drive the stateless inner and never touch the wiring.
THE TICKET'S PREMISE WAS HALF WRONG, AND CHECKING BEAT ASSUMING. #156 was filed
claiming a transposition of any two of seventeen bindings would survive the
suite. Measured instead of trusted:
onVideoCodec <-> onAudioCodec -> REJECTED: "Inapplicable candidate(s):
fun setAudioCodec(codec: AudioCodec)"
onCancel <-> onReset -> COMPILES
Every typed binding -- container, both codecs, preset, suggestion, quality,
engine preference -- takes a distinct parameter type, so the compiler is already
the test. Writing assertions against those transpositions would have been
theatre, and this file says so rather than quietly including them.
WHAT IS ACTUALLY AT RISK is the `() -> Unit` bindings, which are interchangeable
to the compiler: two on the converter screen (onCancel, onReset) and *three* on
the join screen (onJoin, onCancel, onReset). A Cancel button that discards the
finished file, a Start-over that leaves it on screen, or a Join button that
cancels -- each is one wrong word and each ships.
I got that wrong in the first check too: an early run reported the onCancel/
onReset swap as rejected, from a grep-and-exit-code test that misread a stale
build. Re-running it properly printed BUILD SUCCESSFUL with the swap in place.
THE SEAM. `converterActions(viewModel, onPickInput, onConvert, onSave)` and
`joinActions(viewModel, onPickInputs, onSave)`. The launcher-backed actions stay
parameters -- they need an ActivityResultLauncher, which is the part that
genuinely needs a composition, and keeping them out means the rest needs none.
Told apart by effect rather than by a recording double: `reset()` sets the state
to Idle, `cancel()` with no active job leaves it alone (`activeWorkId?.let`,
which SettingsEditsTest pins).
Mutations -- every transposition caught, each by two tests:
converter onCancel <-> onReset | 2 tests
join onJoin <-> onCancel | 2 tests
join onReset <-> onCancel | 2 tests
a typed binding dropped to {} | 1 test
a launcher action rerouted | 1 test
The two-test symmetry is deliberate: one direction alone passes against a wiring
with BOTH actions bound to the same method, which is what a copy-pasted line
produces.
Three guard assertions earned their place during writing -- the picks land
through an injected dispatcher, and without `ParkedPickDispatcher.runAll()` all
three state-based tests sat on Idle and would have asserted nothing. They failed
loudly instead of passing quietly.
`@UnstableApi` on both builders, per CLAUDE.md; lint caught their absence, as it
did in W1.
525 -> 537 tests, 88.0% -> 88.9% line, 70.5% -> 75.4% branch. Gate green.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
JMR-devandClaude Opus 5
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