Socket connect no longer synchronous and blocking

Summary:
Never really liked this code. Before this change, calls to connect were blocking.

Because of this, we had to make use of promises and a bit of really not that good-looking code.

So, this change makes connect non-blocking meaning that we make full use of our event handler.

These changes contain:
- CSR is not getting generated after each failed attempt.
- Connect is no longer blocking.
- Do not report events via the handler when explicitly disconnecting.

Reviewed By: jknoxville

Differential Revision: D46853228

fbshipit-source-id: 00e6a9c7c039a756175fe14982959e078d92bacb

iOS/FlipperKit/FlipperPlatformWebSocket.mm

@@ -181,11 +181,6 @@ static constexpr int connectionKeepaliveSeconds = 10;
 
   [_dispatchQueue cancelAllOperations];
   [_dispatchQueue waitUntilAllOperationsAreFinished];
-
-  // Manually trigger a 'close' event as SocketRocket close method will
-  // not notify the delegate. SocketRocket only triggers the close event
-  // when the connection is closed from the server.
-  _eventHandler(facebook::flipper::SocketEvent::CLOSE);
 }
 
 - (void)send:(NSString*)message

iOS/FlipperKit/FlipperWebSocket.h

@@ -39,7 +39,7 @@ class FlipperWebSocket : public FlipperSocket {
   virtual void setEventHandler(SocketEventHandler eventHandler) override;
   virtual void setMessageHandler(SocketMessageHandler messageHandler) override;
 
-  virtual bool connect(FlipperConnectionManager* manager) override;
+  virtual void connect(FlipperConnectionManager* manager) override;
   virtual void disconnect() override;
 
   virtual void send(const folly::dynamic& message, SocketSendHandler completion)

iOS/FlipperKit/FlipperWebSocket.mm

@@ -53,9 +53,9 @@ void FlipperWebSocket::setMessageHandler(SocketMessageHandler messageHandler) {
   messageHandler_ = std::move(messageHandler);
 }
 
-bool FlipperWebSocket::connect(FlipperConnectionManager* manager) {
+void FlipperWebSocket::connect(FlipperConnectionManager* manager) {
   if (socket_ != NULL) {
-    return true;
+    return;
   }
 
   std::string connectionURL = endpoint_.secure ? "wss://" : "ws://";
@@ -72,43 +72,16 @@ bool FlipperWebSocket::connect(FlipperConnectionManager* manager) {
     connectionURL += payload;
   }
 
-  __block bool fullfilled = false;
-  __block std::promise<bool> promise;
-  auto connected = promise.get_future();
-
   NSURL* urlObjc = [NSURL
       URLWithString:[NSString stringWithUTF8String:connectionURL.c_str()]];
 
-  auto eventHandler = eventHandler_;
   socket_ = [[FlipperPlatformWebSocket alloc] initWithURL:urlObjc];
   socket_.eventHandler = ^(SocketEvent event) {
-    /**
-       Only fulfill the promise the first time the event handler is used. If the
-       open event is received, then set the promise value to true. For any other
-       event, consider a failure and set to false.
-     */
-    if (!fullfilled) {
-      fullfilled = true;
-      if (event == SocketEvent::OPEN) {
-        promise.set_value(true);
-      } else if (event == SocketEvent::SSL_ERROR) {
-        try {
-          promise.set_exception(
-              std::make_exception_ptr(SSLException("SSL handshake failed")));
-        } catch (...) {
-          // set_exception() may throw an exception
-          // In that case, just set the value to false.
-          promise.set_value(false);
-        }
-      } else {
-        promise.set_value(false);
-      }
-    }
-    eventHandler(event);
+    eventHandler_(event);
   };
-  auto messageHandler = messageHandler_;
+
   socket_.messageHandler = ^(const std::string& message) {
-    messageHandler(message);
+    messageHandler_(message);
   };
 
   if (endpoint_.secure) {
@@ -124,8 +97,6 @@ bool FlipperWebSocket::connect(FlipperConnectionManager* manager) {
   }
 
   [socket_ connect];
-
-  return connected.get();
 }
 
 void FlipperWebSocket::disconnect() {
@@ -157,9 +128,9 @@ void FlipperWebSocket::send(
 }
 
 /**
-    Only ever used for insecure connections to receive the device_id from a
-    signCertificate request. If the intended usage ever changes, then a better
-    approach needs to be put in place.
+ * Only ever used for insecure connections to receive the device_id from a
+ * signCertificate request. If the intended usage ever changes, then a better
+ * approach needs to be put in place.
  */
 void FlipperWebSocket::sendExpectResponse(
     const std::string& message,