support the rememberUpgrade option

src/test/java/com/github/nkzawa/engineio/client/ServerConnectionTest.java

@@ -311,4 +311,127 @@ public class ServerConnectionTest {
         assertThat(messages.take(), is("foo"));
         socket.close();
     }
+
+    @Test(timeout = TIMEOUT)
+    public void rememberWebsocket() throws URISyntaxException, InterruptedException {
+        final Semaphore semaphore = new Semaphore(0);
+
+        EventThread.exec(new Runnable() {
+            @Override
+            public void run() {
+                Socket.Options opts = new Socket.Options();
+                opts.port = PORT;
+
+                final Socket socket = new Socket(opts) {
+                    @Override
+                    public void onopen() {
+                    }
+
+                    @Override
+                    public void onmessage(String data) {
+                    }
+
+                    @Override
+                    public void onclose() {
+                    }
+
+                    @Override
+                    public void onerror(Exception err) {
+                    }
+                };
+
+                socket.on(Socket.EVENT_UPGRADE, new Emitter.Listener() {
+                    @Override
+                    public void call(Object... args) {
+                        Transport transport = (Transport) args[0];
+                        socket.close();
+                        if (WebSocket.NAME.equals(transport.name)) {
+                            Socket.Options opts = new Socket.Options();
+                            opts.port = PORT;
+                            opts.rememberUpgrade = true;
+
+                            final Socket socket2 = new Socket(opts) {
+                                @Override
+                                public void onopen() {
+                                }
+
+                                @Override
+                                public void onmessage(String data) {
+                                }
+
+                                @Override
+                                public void onclose() {
+                                }
+
+                                @Override
+                                public void onerror(Exception err) {
+                                }
+                            };
+                            socket2.open();
+                            assertThat(socket2.transport.name, is(WebSocket.NAME));
+                        }
+                        semaphore.release();
+                    }
+                });
+                socket.open();
+                assertThat(socket.transport.name, is(Polling.NAME));
+            }
+        });
+        semaphore.acquire();
+    }
+
+    @Test(timeout = TIMEOUT)
+    public void notRememberWebsocket() throws URISyntaxException, InterruptedException {
+        final Semaphore semaphore = new Semaphore(0);
+
+        EventThread.exec(new Runnable() {
+            @Override
+            public void run() {
+                Socket.Options opts = new Socket.Options();
+                opts.port = PORT;
+
+                final Socket socket = new Socket(opts) {
+                    @Override
+                    public void onopen() {}
+                    @Override
+                    public void onmessage(String data) {}
+                    @Override
+                    public void onclose() {}
+                    @Override
+                    public void onerror(Exception err) {}
+                };
+
+                socket.on(Socket.EVENT_UPGRADE, new Emitter.Listener() {
+                    @Override
+                    public void call(Object... args) {
+                        Transport transport = (Transport)args[0];
+                        socket.close();
+                        if (WebSocket.NAME.equals(transport.name)) {
+                            Socket.Options opts = new Socket.Options();
+                            opts.port = PORT;
+                            opts.rememberUpgrade = false;
+
+                            final Socket socket2 = new Socket(opts) {
+                                @Override
+                                public void onopen() {}
+                                @Override
+                                public void onmessage(String data) {}
+                                @Override
+                                public void onclose() {}
+                                @Override
+                                public void onerror(Exception err) {}
+                            };
+                            socket2.open();
+                            assertThat(socket2.transport.name, is(not(WebSocket.NAME)));
+                        }
+                        semaphore.release();
+                    }
+                });
+                socket.open();
+                assertThat(socket.transport.name, is(Polling.NAME));
+            }
+        });
+        semaphore.acquire();
+    }
+
 }

src/test/java/com/github/nkzawa/engineio/client/SocketTest.java

@@ -12,6 +12,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Timer;
 import java.util.TimerTask;
+import java.util.concurrent.Semaphore;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
@@ -42,13 +43,14 @@ public class SocketTest {
     }
 
     /**
-     * should not emit close on incorrect connection.
+     * should emit close on incorrect connection.
      *
      * @throws URISyntaxException
      * @throws InterruptedException
      */
     @Test
     public void socketClosing() throws URISyntaxException, InterruptedException {
+        final Semaphore semaphore = new Semaphore(0);
         Socket socket = new Socket("ws://0.0.0.0:8080") {
             @Override
             public void onopen() {}
@@ -68,7 +70,8 @@ public class SocketTest {
                 timer.schedule(new TimerTask() {
                     @Override
                     public void run() {
-                        assertThat(closed[0], is(false));
+                        assertThat(closed[0], is(true));
+                        semaphore.release();
                     }
                 }, 20);
             }
@@ -81,5 +84,7 @@ public class SocketTest {
             }
         });
         socket.open();
+        semaphore.acquire();
     }
+
 }

src/test/java/com/github/nkzawa/engineio/client/TransportTest.java

@@ -14,6 +14,8 @@ import static org.junit.Assert.assertThat;
 @RunWith(JUnit4.class)
 public class TransportTest {
 
+    // NOTE: tests for the rememberUpgrade option are on ServerConnectionTest.
+
     @Test
     public void uri() {
         Transport.Options opt = new Transport.Options();