Interface MicroTaskOptions

Provide a custom scheduling function to use when native queueMicrotask is unavailable. When specified, this takes precedence over both the Promise fallback and the timer-backed queue fallback, regardless of whether Promise support is available.

When true, skips the Promise fallback and uses scheduleTimeout(..., 0) instead. When scheduleFn is not provided, this option controls whether to use scheduleTimeout(..., 0) as the fallback instead of Promise.resolve().then(...). A per-call value of false explicitly opts back in to the Promise fallback even when the global default set via setMicroTaskFallbackOptions has useTimeout: true.