[BE2] #1749 Start connection upon start

be2-scala/src/main/scala/ch/epfl/pop/decentralized/Monitor.scala

@@ -105,6 +105,8 @@ private class FileMonitor(mediatorRef: ActorRef) extends Runnable {
   directory.register(watchService, ENTRY_MODIFY)
 
   override def run(): Unit = {
+    // Upon start, we connect to the servers
+    mediatorRef ! ConnectionMediator.ConnectTo(readServerPeers())
     try {
       while (!Thread.currentThread().isInterrupted) {
         // Blocks until an event happen

be2-scala/src/test/scala/ch/epfl/pop/decentralized/MonitorSuite.scala

@@ -105,13 +105,38 @@ class MonitorSuite extends TestKit(ActorSystem("MonitorSuiteActorSystem")) with
     testProbe.expectMsgType[Monitor.GenerateAndSendHeartbeat](timeout)
   }
 
-  test("monitor should send ConnectTo() requests to ConnectionMediator upon relevant config file change") {
+  test("monitor should send a ConnectTo() upon creation") {
     val mockConnectionMediator = TestProbe()
+
+    // Write to mock server peers config file
+    val mockConfig = List("mockConfig")
+    testWriteToServerPeersConfig(mockConfig)
+
     val monitorRef = system.actorOf(Monitor.props(ActorRef.noSender))
 
     // Ping monitor to inform it of ConnectionMediatorRef
     mockConnectionMediator.send(monitorRef, ConnectionMediator.Ping())
 
+    // Expect first read of the server peers list
+    mockConnectionMediator.expectMsgType[ConnectionMediator.ConnectTo](timeout)
+
+  }
+
+  test("monitor should send ConnectTo() requests to ConnectionMediator upon relevant config file change besides first read") {
+    val mockConnectionMediator = TestProbe()
+
+    // Write to mock server peers config file
+    val mockConfig = List("mockConfig")
+    testWriteToServerPeersConfig(mockConfig)
+
+    val monitorRef = system.actorOf(Monitor.props(ActorRef.noSender))
+
+    // Ping monitor to inform it of ConnectionMediatorRef
+    mockConnectionMediator.send(monitorRef, ConnectionMediator.Ping())
+
+    // Expect first read of the server peers list
+    mockConnectionMediator.expectMsgType[ConnectionMediator.ConnectTo](timeout)
+
     // Expect no message as long as the server peers list is untouched
     mockConnectionMediator.expectNoMessage(timeout)
 
@@ -121,13 +146,20 @@ class MonitorSuite extends TestKit(ActorSystem("MonitorSuiteActorSystem")) with
     mockConnectionMediator.expectMsgType[ConnectionMediator.ConnectTo](timeout)
   }
 
-  test("monitor should not react upon non relevant events in config directory") {
+  test("monitor should not react upon non relevant events in config directory besides first read") {
     val mockConnectionMediator = TestProbe()
     val monitorRef = system.actorOf(Monitor.props(ActorRef.noSender))
 
+    // Write to mock server peers config file
+    val mockConfig = List("mockConfig")
+    testWriteToServerPeersConfig(mockConfig)
+
     // Ping monitor to inform it of ConnectionMediatorRef
     mockConnectionMediator.send(monitorRef, ConnectionMediator.Ping())
 
+    // Expect first read of the server peers list
+    mockConnectionMediator.expectMsgType[ConnectionMediator.ConnectTo](timeout)
+
     // Create new file in the directory
     val filePath = Path.of(serverPeersListPath).getParent.toString + File.separator + "DELETE_ME"
     val file = new PrintWriter(filePath)