Test empty group and reformat style

src/main/java/xyz/alexcrea/cuanvil/api/ConflictAPI.java

@@ -19,7 +19,8 @@ import java.util.List;
 @SuppressWarnings("unused")
 public class ConflictAPI {
 
-    private ConflictAPI() {}
+    private ConflictAPI() {
+    }
 
     private static Object saveChangeTask = null;
     private static Object reloadChangeTask = null;
@@ -102,7 +103,8 @@ public class ConflictAPI {
         List<String> excludedGroups = new ArrayList<>(builder.getExcludedGroupNames());
         if (!enchantments.isEmpty()) config.set(basePath + "enchantments", enchantments);
         if (!excludedGroups.isEmpty()) config.set(basePath + "notAffectedGroups", excludedGroups);
-        if(builder.getMaxBeforeConflict() > 0) config.set(basePath + "maxEnchantmentBeforeConflict", builder.getMaxBeforeConflict());
+        if (builder.getMaxBeforeConflict() > 0)
+            config.set(basePath + "maxEnchantmentBeforeConflict", builder.getMaxBeforeConflict());
 
         if (!config.isConfigurationSection(name)) return false;
 
@@ -114,6 +116,7 @@ public class ConflictAPI {
 
     /**
      * Extract every enchantment names from a builder.
+     *
      * @param builder The builder storing the enchantments
      * @return Builder's stored enchantment.
      */
@@ -183,6 +186,7 @@ public class ConflictAPI {
 
     /**
      * Get every registered conflict.
+     *
      * @return An immutable collection of conflict.
      */
     @NotNull

src/main/java/xyz/alexcrea/cuanvil/api/MaterialGroupApi.java

@@ -22,7 +22,8 @@ import java.util.*;
 @SuppressWarnings("unused")
 public class MaterialGroupApi {
 
-    private MaterialGroupApi(){}
+    private MaterialGroupApi() {
+    }
 
     private static Object saveChangeTask = null;
     private static Object reloadChangeTask = null;
@@ -225,6 +226,7 @@ public class MaterialGroupApi {
 
     /**
      * Get every registered material groups.
+     *
      * @return An immutable map of group name as its key and group as mapped value.
      */
     @NotNull

src/test/java/xyz/alexcrea/cuanvil/api/ConflictApiTests.java

@@ -100,6 +100,7 @@ public class ConflictApiTests extends ConfigResetCustomAnvilTest {
     void writeGroup_Reload() {
         String conflictName = "conflict";
         ConflictBuilder builder = new ConflictBuilder(conflictName);
+        builder.addEnchantment("bane_of_arthropods");
 
         // Group not being set should not exist
         assertFalse(doGroupExist(conflictName));
@@ -114,6 +115,24 @@ public class ConflictApiTests extends ConfigResetCustomAnvilTest {
         assertTrue(doGroupExist(conflictName));
     }
 
+    @Test
+    void writeGroup_Empty() {
+        String conflictName = "conflict";
+        ConflictBuilder builder = new ConflictBuilder(conflictName);
+
+        // Group not being set should not exist
+        assertFalse(doGroupExist(conflictName));
+
+        // Add group and reload
+        assertFalse(ConflictAPI.writeConflict(builder));
+        assertFalse(doGroupExist(conflictName));
+
+        // Tick so write get reloaded
+        server.getScheduler().performOneTick();
+
+        assertFalse(doGroupExist(conflictName));
+    }
+
     @Test
     void writeGroup_InvalidDot() {
         String conflictName = "conflict.conflict";

src/test/java/xyz/alexcrea/cuanvil/api/MaterialGroupApiTests.java

@@ -1,5 +1,6 @@
 package xyz.alexcrea.cuanvil.api;
 
+import org.bukkit.Material;
 import org.junit.jupiter.api.Test;
 import xyz.alexcrea.cuanvil.group.EnchantConflictGroup;
 import xyz.alexcrea.cuanvil.group.IncludeGroup;
@@ -14,6 +15,7 @@ public class MaterialGroupApiTests extends ConfigResetCustomAnvilTest {
     void groupAddAndRemove() {
         String groupName = "group";
         IncludeGroup group = new IncludeGroup(groupName);
+        group.addToPolicy(Material.DIAMOND_PICKAXE); // We do not want it to be empty
 
         // Group not being set should not exist
         assertFalse(doGroupExist(groupName));
@@ -46,6 +48,7 @@ public class MaterialGroupApiTests extends ConfigResetCustomAnvilTest {
     void writeGroup_Reload() {
         String groupName = "group";
         IncludeGroup group = new IncludeGroup(groupName);
+        group.addToPolicy(Material.DIAMOND_PICKAXE); // We do not want it to be empty
 
         // Group not being set should not exist
         assertFalse(doGroupExist(groupName));
@@ -63,6 +66,22 @@ public class MaterialGroupApiTests extends ConfigResetCustomAnvilTest {
         assertTrue(doGroupCanBeFound(groupName));
     }
 
+    @Test
+    void writeGroup_Empty() {
+        String groupName = "group";
+        IncludeGroup group = new IncludeGroup(groupName);
+
+        // Add group and reload
+        assertFalse(MaterialGroupApi.writeMaterialGroup(group));
+        assertFalse(doGroupExist(groupName));
+        assertFalse(doGroupCanBeFound(groupName));
+
+        // Tick so write get reloaded
+        server.getScheduler().performOneTick();
+
+        assertFalse(doGroupExist(groupName));
+        assertFalse(doGroupCanBeFound(groupName));
+    }
 
     @Test
     void writeGroup_InvalidDot() {