Fixed most reported issues by SonarCloud.

sharding/pom.xml

@@ -40,6 +40,11 @@
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>

sharding/src/main/java/com/iluwatar/sharding/App.java

@@ -36,10 +36,10 @@ public class App {
    */
   public static void main(String[] args) {
 
-    var data1 = new Data(1, "data1", Data.DataType.type1);
-    var data2 = new Data(2, "data2", Data.DataType.type2);
-    var data3 = new Data(3, "data3", Data.DataType.type3);
-    var data4 = new Data(4, "data4", Data.DataType.type1);
+    var data1 = new Data(1, "data1", Data.DataType.TYPE_1);
+    var data2 = new Data(2, "data2", Data.DataType.TYPE_2);
+    var data3 = new Data(3, "data3", Data.DataType.TYPE_3);
+    var data4 = new Data(4, "data4", Data.DataType.TYPE_1);
 
     var shard1 = new Shard(1);
     var shard2 = new Shard(2);

sharding/src/main/java/com/iluwatar/sharding/Data.java

@@ -71,7 +71,7 @@ public class Data {
   }
 
   enum DataType {
-    type1, type2, type3
+    TYPE_1, TYPE_2, TYPE_3
   }
 
   @Override

sharding/src/main/java/com/iluwatar/sharding/RangeShardManager.java

@@ -47,11 +47,11 @@ public class RangeShardManager extends ShardManager {
   protected int allocateShard(Data data) {
     var type = data.getType();
     switch (type) {
-      case type1:
+      case TYPE_1:
         return 1;
-      case type2:
+      case TYPE_2:
         return 2;
-      case type3:
+      case TYPE_3:
         return 3;
       default:
         return -1;

sharding/src/test/java/com/iluwatar/sharding/AppTest.java

@@ -25,14 +25,16 @@ package com.iluwatar.sharding;
 
 import org.junit.Test;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
 /**
  * Unit tests for App class.
  */
 public class AppTest {
 
   @Test
-  public void testMain() {
-    App.main(new String[]{});
+  public void shouldExecuteWithoutException() {
+    assertDoesNotThrow(() -> App.main(new String[]{}));
   }
 
 }

sharding/src/test/java/com/iluwatar/sharding/HashShardManagerTest.java

@@ -56,7 +56,7 @@ public class HashShardManagerTest {
 
   @Test
   public void testStoreData() {
-    var data = new Data(1, "test", Data.DataType.type1);
+    var data = new Data(1, "test", Data.DataType.TYPE_1);
     hashShardManager.storeData(data);
     Assert.assertEquals(data, hashShardManager.getShardById(1).getDataById(1));
   }

sharding/src/test/java/com/iluwatar/sharding/LookupShardManagerTest.java

@@ -52,7 +52,7 @@ public class LookupShardManagerTest {
   @Test
   public void testStoreData() {
     try {
-      var data = new Data(1, "test", Data.DataType.type1);
+      var data = new Data(1, "test", Data.DataType.TYPE_1);
       lookupShardManager.storeData(data);
       var field = LookupShardManager.class.getDeclaredField("lookupMap");
       field.setAccessible(true);

sharding/src/test/java/com/iluwatar/sharding/RangeShardManagerTest.java

@@ -50,7 +50,7 @@ public class RangeShardManagerTest {
 
   @Test
   public void testStoreData() {
-    var data = new Data(1, "test", Data.DataType.type1);
+    var data = new Data(1, "test", Data.DataType.TYPE_1);
     rangeShardManager.storeData(data);
     Assert.assertEquals(data, rangeShardManager.getShardById(1).getDataById(1));
   }

sharding/src/test/java/com/iluwatar/sharding/ShardTest.java

@@ -42,7 +42,7 @@ public class ShardTest {
 
   @Before
   public void setup() {
-    data = new Data(1, "test", Data.DataType.type1);
+    data = new Data(1, "test", Data.DataType.TYPE_1);
     shard = new Shard(1);
   }