axiom-assume-isolated

You can access actor-isolated state synchronously in Swift tests by confirming the current execution context is on the target actor's executor, avoiding unnecessary async/await overhead while directly interacting with the isolated data.

Yes, you can update MainActor state without async/await by using assumeIsolated to synchronously execute operations when you are certain the code is already running on the main thread's execution context.

Synchronous actor access in Swift is used to directly interact with actor state without asynchronous hops, solving performance overhead in critical code, simplifying testing scenarios, and integrating legacy callback patterns.

Yes, synchronous actor access works with legacy delegate patterns by allowing direct, non-async access to isolated data when the delegate guarantees execution is already happening on the specific actor's thread or executor.

You should not use synchronous access for Swift actors when you cannot guarantee the current execution context is on the target actor's executor, as violating this isolation requirement makes the synchronous access unsafe.

The best way to test MainActor isolation without Task overhead is to confirm you are on the main execution context and use assumeIsolated for direct, synchronous access to the isolated state during your test execution.