Testing Effect.run containing Task

[Dmitry-Pliushchai]

HI. I got stuck with testing store in case if action returns Effect.run containing Task. As there is no LongLivingEffect await store.receive does not wait for result but failes immediately. Could you advise how to deal with the issue?

case .optimizeCars:
 return .run { [cars = state.uploaderModel.cars] send in
       for car in cars { 
         Task {
           do {
             let result = try await environment.optimizer.optimize(
               car: car
             )
             await send(.carOptimizedSuccess(optimizationResult))
           } catch {
             await send(. carOptimizedFailure(error))
           }
         }
       }
     }

await store.send(.optimizeCars)
await store.receive(. carOptimizedSuccess(.mock)

[stephencelis]

@dpliushchaiIOS Effect.run provides an asynchronous context for you to do async work in, but Task leaves the world of structured concurrency (unless you await the result explicitly, set up cancellation handlers, etc.).

So instead, do the work directly in the task. If you want to parallelize the work done for each item in the loop, you can use a task group, which stays in the structural concurrency world:

case .optimizeCars:
  return .run { [cars = state.uploaderModel.cars] send in
    await withTaskGroup(of: Void.self) { group in
      for car in cars {
        group.addTask {
          do {
            let result = try await environment.optimizer.optimize(
              car: car
            )
            await send(.carOptimizedSuccess(optimizationResult))
          } catch {
            await send(.carOptimizedFailure(error))
          }
        }
      }
    }
  }