Fixing a bug when stopping a disconnected connection (#283)

* fixing a bug when stopping a disconnected connection

* add stop connection when disconnected unit test

* check disconnected state refactoring

Author: marwendoukh

Sources/SignalRClient/ReconnectableConnection.swift

@@ -71,8 +71,11 @@ internal class ReconnectableConnection: Connection {
 
     func stop(stopError: Error?) {
         logger.log(logLevel: .info, message: "Received connection stop request")
-        _ = changeState(from: nil, to: .stopping)
-        underlyingConnection.stop(stopError: stopError)
+        if changeState(from: [.starting, .reconnecting, .running], to: .stopping) != nil {
+          underlyingConnection.stop(stopError: stopError)
+        } else {
+          logger.log(logLevel: .warning, message: "Reconnectable connection is already in the disconnected state. Ignoring stop request")
+        }
     }
 
     private func startInternal() {

Tests/SignalRClientTests/ReconnectableConnectionTests.swift

@@ -235,29 +235,65 @@ class ReconnectableConnectionTests: XCTestCase {
 
         waitForExpectations(timeout: 2 /*seconds*/)
     }
-
-
+    
+    public func testReconnectableConnectionIgnoreStopRequestWhenDisconnected() {
+        
+        var isConnectionOpen = false
+        
+        let testConnection = TestConnection()
+        let delegate = TestConnectionDelegate()
+        let reconnectableConnection = ReconnectableConnection(connectionFactory: {return testConnection}, reconnectPolicy: NoReconnectPolicy(), callbackQueue: callbackQueue, logger: PrintLogger())
+        reconnectableConnection.delegate = delegate
+        
+        delegate.connectionDidOpenHandler = { connection in
+            isConnectionOpen = true
+        }
+        
+        delegate.connectionDidCloseHandler = { connection in
+            isConnectionOpen = false
+        }
+        
+        reconnectableConnection.start()
+        XCTAssertTrue(isConnectionOpen)
+        
+        reconnectableConnection.stop(stopError: nil)
+        XCTAssertTrue(!isConnectionOpen)
+        
+        // stop the connection while it is disconnected
+        reconnectableConnection.stop(stopError: nil)
+        XCTAssertTrue(!isConnectionOpen)
+        
+        reconnectableConnection.start()
+        XCTAssertTrue(isConnectionOpen)
+    }
+    
     class TestConnection: Connection {
         var delegate: ConnectionDelegate?
         var openError: Error?
-
+        
         var connectionId: String?
         var inherentKeepAlive = false
-
+        var isClosed: Bool = false
+        
         func start() {
             if let e = openError {
                 delegate?.connectionDidFailToOpen(error: e)
             } else {
                 delegate?.connectionDidOpen(connection: self)
+                self.isClosed = false
             }
         }
-
+        
         func send(data: Data, sendDidComplete: (Error?) -> Void) {
             sendDidComplete(nil)
         }
-
+        
         func stop(stopError: Error?) {
+            // Recreating the logic as in HTTPConnection. (the delegate method would only be called when the connection state changes to stopped. Therefore the state transition of ReconnectableConnection to disconnected will not be executed
+            guard !self.isClosed else { return }
+            self.isClosed = true
             delegate?.connectionDidClose(error: stopError)
         }
+        
     }
 }