create testable LocalHTTPDManager for controlling the webserver

The RxJava tricks were a nightmare...

app/src/testFull/java/org/fdroid/fdroid/localrepo/LocalHTTPDManagerTest.java

@@ -0,0 +1,72 @@
+package org.fdroid.fdroid.localrepo;
+
+import android.content.Context;
+import org.fdroid.fdroid.FDroidApp;
+import org.fdroid.fdroid.Utils;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.shadows.ShadowLog;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+
+@RunWith(RobolectricTestRunner.class)
+public class LocalHTTPDManagerTest {
+
+    @Test
+    public void testStartStop() throws InterruptedException {
+        ShadowLog.stream = System.out;
+        Context context = RuntimeEnvironment.application;
+
+        final String host = "localhost";
+        final int port = 8888;
+        assertFalse(Utils.isServerSocketInUse(port));
+        LocalHTTPDManager.stop(context);
+
+        FDroidApp.ipAddressString = host;
+        FDroidApp.port = port;
+
+        LocalHTTPDManager.start(context, false);
+        final CountDownLatch startLatch = new CountDownLatch(1);
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                while (!Utils.isServerSocketInUse(port)) {
+                    try {
+                        Thread.sleep(500);
+                    } catch (InterruptedException e) {
+                        fail();
+                    }
+                }
+                startLatch.countDown();
+            }
+        }).start();
+        assertTrue(startLatch.await(30, TimeUnit.SECONDS));
+        assertTrue(Utils.isServerSocketInUse(port));
+        assertTrue(Utils.canConnectToSocket(host, port));
+
+        LocalHTTPDManager.stop(context);
+        final CountDownLatch stopLatch = new CountDownLatch(1);
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                while (!Utils.isServerSocketInUse(port)) {
+                    try {
+                        Thread.sleep(500);
+                    } catch (InterruptedException e) {
+                        fail();
+                    }
+                }
+                stopLatch.countDown();
+            }
+        }).start();
+        assertTrue(stopLatch.await(10, TimeUnit.SECONDS));
+    }
+}