Proof

react-native-background-timer

native-seam only — the real upstream BackgroundTimer class (uniqueId counter, callbacks map keyed by timer id, runBackgroundTimer/backgroundClockMethod, setTimeout/clearTimeout/setInterval/clearInterval multiplexing through NativeEventEmitter) runs from the bundle. sootsim registers the RNBackgroundTimer TurboModule; setTimeout(id, timeout) schedules a real browser setTimeout that emits `backgroundTimer.timeout` carrying the id (NativeEventEmitter consumes via the __sootsimEmitBus slot), clearTimeout cancels.

90%

API coverage

No visual proof cases have been published for this package yet. The registry summary below describes what the compat layer implements.

Working (7)

real upstream BackgroundTimer class running from the bundlerunBackgroundTimer / stopBackgroundTimer (start + listener bookkeeping)startstopsetTimeout / clearTimeout (multiplexed by id, real browser scheduling)setInterval / clearInterval (re-arming via the same id)backgroundClockMethod recursive scheduling

Missing

background execution not possible in browser — timers pause when tabs are backgrounded (inherent platform limit, identical to iOS losing its background-execution budget)