Adds a couple of unit tests for the browser

add-on/src/addon/javascript/background.js

@@ -89,6 +89,9 @@ var listeners = [function (message, returnValue) {
         }
         switch (type)
         {
+        case "NumberPing":
+            returnValue = message.number;
+            break;
         case "CommandLoadSong":
             returnValue = () => {
                 if (message.song)

browser/build.gradle

@@ -60,7 +60,8 @@ dependencies {
 	implementation 'org.apache.logging.log4j:log4j-core:2.13.3'
 	implementation 'org.apache.logging.log4j:log4j-slf4j-impl:2.13.3'
 	implementation project(":browserCommands")
-	addon project(path: ":add-on", configuration: 'addonBuild')
+    testImplementation 'junit:junit:4.12'
+    addon project(path: ":add-on", configuration: 'addonBuild')
 }
 
 task downloadWindows_x86_64(type: Download) {

browser/src/test/java/PingTest.java

@@ -0,0 +1,76 @@
+import static org.junit.Assert.assertEquals;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import edu.regis.universeplayer.NumberPing;
+import edu.regis.universeplayer.browser.Browser;
+import edu.regis.universeplayer.browserCommands.CommandReturn;
+
+public class PingTest
+{
+    @BeforeClass
+    public static void setupBrowser() throws IOException, InterruptedException
+    {
+        System.out.println("Creating browser");
+        Browser.createBrowser();
+        System.out.println("Browser created");
+        if (Browser.getInstance() == null)
+        {
+            Browser.waitInstance();
+        }
+        Thread thread = new Thread(Browser.getInstance());
+        thread.start();
+        System.out.println("Browser fully initialized");
+    }
+
+    @AfterClass
+    public static void closeBrowser() throws IOException, InterruptedException
+    {
+        Browser.getInstance().stop();
+        System.out.println("Browser closed");
+    }
+
+    @Test
+    public void testPing() throws IOException, InterruptedException, ExecutionException
+    {
+        ArrayList<Future<Object>> futures = new ArrayList<>();
+        for (int i = 0; i < 3; i++)
+        {
+            futures.add(Browser.getInstance().sendObject("ping"));
+        }
+        System.out.println("Pings sent");
+        for (int i = 0; i < futures.size(); i++)
+        {
+            assertEquals("pong",
+                    ((CommandReturn<String>) futures.get(i).get())
+                            .getReturnValue());
+        }
+        System.out.println("Objects received");
+    }
+
+    @Test
+    public void testNumPing() throws IOException, InterruptedException,
+            ExecutionException
+    {
+        ArrayList<Future<Object>> futures = new ArrayList<>();
+        for (int i = 0; i < 3; i++)
+        {
+            futures.add(Browser.getInstance().sendObject(new NumberPing(i)));
+        }
+        System.out.println("Numbered pings sent");
+        for (int i = 0; i < futures.size(); i++)
+        {
+            assertEquals(i,
+                    ((CommandReturn<Double>) futures.get(i).get())
+                            .getReturnValue(), 0.001);
+        }
+        System.out.println("Objects received");
+    }
+}

browserCommands/src/main/java/edu/regis/universeplayer/NumberPing.java

@@ -0,0 +1,21 @@
+package edu.regis.universeplayer;
+
+import java.io.Serializable;
+
+/**
+ * A test class for pinging the browser.
+ */
+public class NumberPing implements Serializable
+{
+    public int number;
+
+    public NumberPing()
+    {
+        this(0);
+    }
+
+    public NumberPing(int number)
+    {
+        this.number = number;
+    }
+}