FFmpegEngine derives progress as stats.time / durationMs * 100, and the
statistics callback runs on every conversion in FFmpegEngineTest -- they
all pass durationMs = 3_000. But every call site omits onProgress, so
nothing on any source set had ever looked at the number. Replacing percent
with a constant reddened nothing.
What already existed covers the plumbing downstream and not this: #196
covered the worker's progress lambda with a fake engine that reports
whatever the test tells it to, and ProgressNotificationTest covers the
throttling the same way. The arithmetic was the one part with no reader.
The new test passes 30 s as the duration for a fixture that is exactly
3.000 s, so the conversion still encodes the whole clip and the reported
percentage tops out around 10 rather than 100.
That is what makes it bite. A range check alone is worthless: a constant 0
satisfies both "every value is in 0..100" and "the values never go
backwards", and so does a list of [0, 100]. Pinning the band rejects every
constant, and because the band sits a tenth of the way up it also rejects
an implementation that ignores durationMs, which would report ~100 for the
same run. The bound is loose -- 5..25 for an expected 10 -- because the
last statistics callback can land slightly before the final frame.
Verified on a local API 34 emulator: 61 tests, 0 failures, 3 skipped.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
JMR-devandClaude Opus 5