Async await support#74
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The SwiftStateTests test target pointed at `path:"Sources"`, which overlapped the library target's sources and broke `swift build`, running zero tests. Point it at `Tests/SwiftStateTests`.
Without an explicit `platforms:` floor, SPM assumes an ancient deployment target and `async` code fails with "concurrency is only available in iOS 13.0.0 or newer". Set iOS 13 / macOS 10.15 / tvOS 13 / watchOS 6.
AsyncStateMachine<S, E> wraps a private StateMachine and exposes
`async` transition handlers plus `async` tryEvent/tryState that return
only after all matching handlers have finished. This lets consumers
await async work as part of a transition instead of fire-and-forget
`Task {}`.
Implemented as a thin wrapper so the existing sync API is unchanged:
each async handler is registered on the wrapped machine as a tiny
synchronous collector that enqueues the matched (handler, context); the
async drive then commits the transition via the wrapped machine (which
performs all routing, conditions, ordering and error matching) and
awaits the queued handlers in order. No routing logic is duplicated.
Conditions and route mappings remain synchronous. AsyncStateMachine is
not re-entrancy/concurrency safe; drive it from a single context.
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We've been using SwiftState in Element X for quite some time now and we love it so thank you! There are places were we need to call async methods in the handlers though, so I've been toying with the idea of an async verion of the state machine.
This is what I came up with (heavily LLMed) and would love to hear your thoughts on it:
Adds
AsyncStateMachine<S, E>, a thin wrapper aroundStateMachinethat lets transition handlers beasync.tryEventandtryStateare nowasyncand return only after all matched handlers have finished — no more fire-and-forgetTask {}workarounds.All routing, conditions, orderin g, and state commits are delegated entirely to the wrapped
StateMachine. The only addition is that handlers can nowawaitwork before the caller continues.Thread safety is not provided, that's left to the caller and the machine must be driven from a single thread or actor.
Also makes two
Package.swiftchanges:platforms(iOS 13 / macOS 10.15 / tvOS 13 / watchOS 6) — required forasyncsupportSources(nowTests/SwiftStateTests), which brokeswift buildbecause of overlapping sources