Fixed problem with processing of client ACK packet

  * Problem in missed ```fallthrough``` in switch between _ACK and _BINARY_ACK
  * Added tests for checking _ACK and _BINARY_ACK client packet processing

Author: CyberLight

handler.go

@@ -134,6 +134,7 @@ func (h *socketHandler) onPacket(decoder *decoder, packet *packet) ([]interface{
 	case _ERROR:
 		message = "error"
 	case _ACK:
+		fallthrough
 	case _BINARY_ACK:
 		return nil, h.onAck(packet.Id, decoder, packet)
 	default:

handler_test.go

@@ -0,0 +1,105 @@
+package socketio
+
+import (
+	"testing"
+
+	. "github.com/smartystreets/goconvey/convey"
+	"net/http"
+	"io"
+	"github.com/googollee/go-engine.io"
+)
+
+type FakeBroadcastAdaptor struct {}
+
+func (f *FakeBroadcastAdaptor) Join(room string, socket Socket) error {
+	return nil
+}
+
+func (f *FakeBroadcastAdaptor) Leave(room string, socket Socket) error {
+	return nil
+}
+
+func (f *FakeBroadcastAdaptor) Send(ignore Socket, room, event string, args ...interface{}) error {
+	return nil
+}
+
+type FakeReadCloser struct {}
+
+func (fr *FakeReadCloser) Read(p []byte) (n int, err error) {
+	p = append(p, byte(128))
+	return 1, nil
+}
+
+func (fr *FakeReadCloser) Close() error {
+	return nil
+}
+
+type FakeWriteCloser struct {}
+
+func (fr *FakeWriteCloser) Write(p []byte) (n int, err error) {
+	return len(p), nil
+}
+
+func (fr *FakeWriteCloser) Close() error {
+	return nil
+}
+
+type FakeSockConnection struct {}
+
+func (f *FakeSockConnection) Id() string {
+	return "test1"
+}
+
+func (f *FakeSockConnection) Request() *http.Request {
+	return &http.Request{}
+}
+
+func (f *FakeSockConnection) Close() error {
+	return nil
+}
+
+func (f *FakeSockConnection) NextReader() (engineio.MessageType, io.ReadCloser, error) {
+	return engineio.MessageText, &FakeReadCloser{}, nil
+}
+
+func (f *FakeSockConnection) NextWriter(messageType engineio.MessageType) (io.WriteCloser, error) {
+	return &FakeWriteCloser{}, nil
+}
+
+
+func TestHandler(t *testing.T) {
+	//BugFix missed
+	//Method: handler.onPacket
+	//Reason: missed fallthrough after case _ACK:
+	//
+	// 	case _ACK:
+	//		fallthrough   <---- fixed problem
+	//
+	Convey("Call ACK handler by ACK id received from client", t, func() {
+		saver := &FrameSaver{}
+		var handlerCalled bool
+		baseHandlerInstance := newBaseHandler("some:event", &FakeBroadcastAdaptor{})
+		socketInstance := newSocket(&FakeSockConnection{}, baseHandlerInstance)
+		c, _ := newCaller(func () {handlerCalled = true})
+
+		socketInstance.acks[0] = c
+		socketInstance.onPacket(newDecoder(saver), &packet{Type:_ACK, Id:0, Data:"[]", NSP:"/"})
+
+		So(len(socketInstance.acks), ShouldEqual, 0)
+		So(handlerCalled, ShouldBeTrue)
+	})
+
+	Convey("Call BINARY ACK handler by BINARY ACK id received from client", t, func() {
+		saver := &FrameSaver{}
+		var handlerCalled bool
+		baseHandlerInstance := newBaseHandler("some:event", &FakeBroadcastAdaptor{})
+		socketInstance := newSocket(&FakeSockConnection{}, baseHandlerInstance)
+		c, _ := newCaller(func () {handlerCalled = true})
+
+		socketInstance.acks[0] = c
+		socketInstance.onPacket(newDecoder(saver), &packet{Type:_BINARY_ACK, Id:0, Data:"[]", NSP:"/"})
+
+		So(len(socketInstance.acks), ShouldEqual, 0)
+		So(handlerCalled, ShouldBeTrue)
+	})
+}