Rename start to start0

And wait for connection start to fail

Author: dnadoba

Sources/AsyncHTTPClient/ConnectionPool/HTTP2/HTTP2Connection.swift

@@ -129,7 +129,7 @@ final class HTTP2Connection {
             delegate: delegate,
             logger: logger
         )
-        return connection.start().map { maxStreams in (connection, maxStreams) }
+        return connection.start0().map { maxStreams in (connection, maxStreams) }
     }
 
     func executeRequest(_ request: HTTPExecutableRequest) {
@@ -164,7 +164,7 @@ final class HTTP2Connection {
         return promise.futureResult
     }
 
-    func start() -> EventLoopFuture<Int> {
+    func start0() -> EventLoopFuture<Int> {
         self.channel.eventLoop.assertInEventLoop()
 
         let readyToAcceptConnectionsPromise = self.channel.eventLoop.makePromise(of: Int.self)

Tests/AsyncHTTPClientTests/HTTP2ConnectionTests.swift

@@ -54,11 +54,13 @@ class HTTP2ConnectionTests: XCTestCase {
             delegate: TestHTTP2ConnectionDelegate(),
             logger: logger
         )
-        _ = connection.start()
+        let startFuture = connection.start0()
 
         XCTAssertNoThrow(try embedded.close().wait())
         // to really destroy the channel we need to tick once
         embedded.embeddedEventLoop.run()
+        
+        XCTAssertThrowsError(try startFuture.wait())
 
         // should not crash
         connection.shutdown()