Switched from plugin.getServer() to Bukkit.getServer() to enable tests

plugin.getServer() cannot be mocked because it is final.

src/main/java/world/bentobox/bentobox/database/mongodb/MongoDBDatabase.java

@@ -1,5 +1,7 @@
 package world.bentobox.bentobox.database.mongodb;
 
+import org.bukkit.Bukkit;
+
 import world.bentobox.bentobox.BentoBox;
 import world.bentobox.bentobox.database.AbstractDatabaseHandler;
 import world.bentobox.bentobox.database.DatabaseConnectionSettingsImpl;
@@ -11,10 +13,10 @@ public class MongoDBDatabase implements DatabaseSetup {
     public <T> AbstractDatabaseHandler<T> getHandler(Class<T> type) {
         BentoBox plugin = BentoBox.getInstance();
         // Check if the MongoDB plugin exists
-        if (plugin.getServer().getPluginManager().getPlugin("BsbMongo") == null) {
+        if (Bukkit.getServer().getPluginManager().getPlugin("BsbMongo") == null) {
             plugin.logError("You must install BsbMongo plugin for MongoDB support!");
             plugin.logError("See: https://github.com/tastybento/bsbMongo/releases/");
-            plugin.getServer().getPluginManager().disablePlugin(plugin);
+            Bukkit.getServer().getPluginManager().disablePlugin(plugin);
             return null;
         }
         return new MongoDBDatabaseHandler<>(plugin, type, new MongoDBDatabaseConnector(new DatabaseConnectionSettingsImpl(

src/main/java/world/bentobox/bentobox/database/objects/Island.java

@@ -720,8 +720,8 @@ public class Island implements DataObject {
             user.sendMessage("commands.admin.info.owner", "[owner]", plugin.getPlayers().getName(owner), "[uuid]", owner.toString());
 
             // Fixes #getLastPlayed() returning 0 when it is the owner's first connection.
-            long lastPlayed = (plugin.getServer().getOfflinePlayer(owner).getLastPlayed() != 0) ?
+            long lastPlayed = (Bukkit.getServer().getOfflinePlayer(owner).getLastPlayed() != 0) ?
-                    plugin.getServer().getOfflinePlayer(owner).getLastPlayed() : plugin.getServer().getOfflinePlayer(owner).getFirstPlayed();
+                    Bukkit.getServer().getOfflinePlayer(owner).getLastPlayed() : Bukkit.getServer().getOfflinePlayer(owner).getFirstPlayed();
                     user.sendMessage("commands.admin.info.last-login","[date]", new Date(lastPlayed).toString());
 
                     user.sendMessage("commands.admin.info.deaths", "[number]", String.valueOf(plugin.getPlayers().getDeaths(world, owner)));

src/main/java/world/bentobox/bentobox/listeners/JoinLeaveListener.java

@@ -175,7 +175,7 @@ public class JoinLeaveListener implements Listener {
         plugin.getIWM().getOverWorlds().forEach(w -> {
             Island island = plugin.getIslands().getIsland(w, User.getInstance(event.getPlayer()));
             // Are there any online players still for this island?
-            if (island != null && plugin.getServer().getOnlinePlayers().stream()
+            if (island != null && Bukkit.getServer().getOnlinePlayers().stream()
                     .filter(p -> !event.getPlayer().equals(p))
                     .noneMatch(p -> plugin.getIslands().getMembers(w, event.getPlayer().getUniqueId()).contains(p.getUniqueId()))) {
                 // No, there are no more players online on this island

src/main/java/world/bentobox/bentobox/util/heads/HeadGetter.java

@@ -7,6 +7,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 
+import org.bukkit.Bukkit;
 import org.bukkit.Material;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.SkullMeta;
@@ -31,7 +32,7 @@ public class HeadGetter {
 
     @SuppressWarnings("deprecation")
     private void runPlayerHeadGetter() {
-        plugin.getServer().getScheduler().runTaskTimerAsynchronously(plugin, () -> {
+        Bukkit.getScheduler().runTaskTimerAsynchronously(plugin, () -> {
             synchronized(names) {
                 Iterator<Entry<String, PanelItem>> it = names.entrySet().iterator();
                 if (it.hasNext()) {
@@ -46,7 +47,7 @@ public class HeadGetter {
                     if (headRequesters.containsKey(en.getKey())) {
                         for (HeadRequester req : headRequesters.get(en.getKey())) {
                             en.getValue().setHead(playerSkull.clone());
-                            plugin.getServer().getScheduler().runTask(plugin, () -> req.setHead(en.getValue()));
+                            Bukkit.getServer().getScheduler().runTask(plugin, () -> req.setHead(en.getValue()));
                         }
                     }
                     it.remove();
@@ -55,7 +56,7 @@ public class HeadGetter {
         }, 0L, 20L);
     }
 
-     /**
+    /**
      * @param panelItem - head to update
      * @param requester - callback class
      */

src/main/java/world/bentobox/bentobox/versions/ServerCompatibility.java

@@ -1,5 +1,6 @@
 package world.bentobox.bentobox.versions;
 
+import org.bukkit.Bukkit;
 import org.bukkit.Server;
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jdt.annotation.Nullable;
@@ -119,7 +120,7 @@ public class ServerCompatibility {
     public Compatibility checkCompatibility(BentoBox plugin) {
         if (result == null) {
             // Check the server version first
-            ServerVersion version = getServerVersion(plugin.getServer());
+            ServerVersion version = getServerVersion(Bukkit.getServer());
 
             if (version == null || version.getCompatibility().equals(Compatibility.INCOMPATIBLE)) {
                 // 'Version = null' means that it's not listed. And therefore, it's implicitly incompatible.
@@ -128,7 +129,7 @@ public class ServerCompatibility {
             }
 
             // Now, check the server software
-            ServerSoftware software = getServerSoftware(plugin.getServer());
+            ServerSoftware software = getServerSoftware(Bukkit.getServer());
 
             if (software == null || software.getCompatibility().equals(Compatibility.INCOMPATIBLE)) {
                 // 'software = null' means that it's not listed. And therefore, it's implicitly incompatible.