Add more tests (#84)

* Add testBadAuthenticationMethod and testAuth

* Don't throw error on already closed channel when closing

* swift format

Author: adam-fowler

Sources/MQTTNIO/MQTTClient.swift

@@ -185,7 +185,11 @@ public final class MQTTClient {
             let closeError: Error?
             switch result {
             case .failure(let error):
-                closeError = error
+                if case ChannelError.alreadyClosed = error {
+                    closeError = nil
+                } else {
+                    closeError = error
+                }
             case .success:
                 closeError = nil
             }

Tests/MQTTNIOTests/MQTTNIOv5Tests.swift

@@ -284,6 +284,19 @@ final class MQTTNIOv5Tests: XCTestCase {
         try client2.disconnect().wait()
     }
 
+    func testBadAuthenticationMethod() throws {
+        let client = self.createClient(identifier: "testSessionExpiryInterval")
+        defer { XCTAssertNoThrow(try client.syncShutdownGracefully()) }
+        XCTAssertThrowsError(_ = try client.v5.connect(properties: [.authenticationMethod("test")]).wait()) { error in
+            switch error {
+            case MQTTError.reasonError(let reason):
+                XCTAssertEqual(reason, .badAuthenticationMethod)
+            default:
+                XCTFail("\(error)")
+            }
+        }
+    }
+
     func testInvalidTopicName() throws {
         let client = self.createClient(identifier: "testInvalidTopicName")
         defer { XCTAssertNoThrow(try client.syncShutdownGracefully()) }
@@ -327,6 +340,24 @@ final class MQTTNIOv5Tests: XCTestCase {
         try client.disconnect().wait()
     }
 
+    func testAuth() throws {
+        let client = self.createClient(identifier: "testReauth")
+        defer { XCTAssertNoThrow(try client.syncShutdownGracefully()) }
+
+        _ = try client.v5.connect().wait()
+        let authFuture = client.v5.auth(properties: []) { _, eventLoop in
+            return eventLoop.makeSucceededFuture(.init(reason: .continueAuthentication, properties: []))
+        }
+        XCTAssertThrowsError(try authFuture.wait()) { error in
+            switch error {
+            case MQTTError.serverClosedConnection:
+                break
+            default:
+                XCTFail("\(error)")
+            }
+        }
+    }
+
     func testSubscribeAll() throws {
         if ProcessInfo.processInfo.environment["CI"] != nil {
             return