AsyncPublisher Blocks subsequent calls

Cole · June 16, 2022, 6:42am

I am experiencing an issue using AsyncPublisher. I have a project where I am waiting to receive connection status updates via a closure from Network.Framework. I am using a publisher to capture the value and report it to an observable object. From there I use Async Publisher in order to loop over the status and perform some logic accordingly. However any calls made after the monitorConnection() method will not be called. It seems we are stuck in the loop or something although the loop doesn't seem to be running after I receive the latest status. Am I forgetting to do something? Here is the link to the source code identifying the problem in a simple test case.

github.com

needle-tail/WhiteTippedSockets/blob/f3cd18fea09803a369de432e6b0245656f0d2f7d/Tests/WhiteTippedTests/WhiteTippedTests.swift#L7


      
          import XCTest
          @testable import WhiteTipped
          
          
final class WhiteTippedTests: XCTestCase {
              
              
              func testConnection() throws {
                  Task {
                  let socket = await WhiteTipped(headers: nil, urlRequest: nil, cookies: nil)
                      await socket.connect(url: URL(string: "ws://192.168.1.177:8080")!)
                      //Never Called
                      await socket.fireAfterConnection()
                  }
              }
          }

Here is where the iteration occurs.

github.com

needle-tail/WhiteTippedSockets/blob/f3cd18fea09803a369de432e6b0245656f0d2f7d/Sources/WhiteTipped/WhiteTipped.swift#L213


      
          
          

          
func notifyDisconnection(with error: NWError? = nil, _ reason: NWProtocolWebSocket.CloseCode) async {
              let result = DisconnectResult(error: error, code: reason)
              await MainActor.run {
                  receiver.disconnectionPacketReceived.send(result)
              }
          }
          
          

          
private func monitorConnection(_ betterPath: Bool = false) async  {
              do {
                  //AsyncPublish prevents currentState from finishing the suspension
                  for await state in connectionState.$currentState.values {
                      switch state {
                      case .setup:
                          logger.trace("Connection setup")
                          
                      case .waiting(let status):
                          logger.trace("Connection waiting with status - Status: \(status.localizedDescription)")

Any thoughts are appreciate,

Thanks in advance

Cole · June 17, 2022, 3:55pm

Turns out to be fairly simple. The loop never stops being monitored I believe. So, we need to exit under certain conditions.

guard state != .setup, state != .preparing else { break }