Added UnitTest cases for adapter.

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

@@ -1,30 +1,28 @@
 package com.iluwatar.adapter;
 
 /**
- *
  * An adapter helps two incompatible interfaces to work together. This is the real world definition
  * for an adapter. Interfaces may be incompatible but the inner functionality should suit the need.
  * The Adapter design pattern allows otherwise incompatible classes to work together by converting
  * the interface of one class into an interface expected by the clients.
- * <p>
- * There are two variations of the Adapter pattern: The class adapter implements the adaptee's
+ * 
+ * <p>There are two variations of the Adapter pattern: The class adapter implements the adaptee's
  * interface whereas the object adapter uses composition to contain the adaptee in the adapter
  * object. This example uses the object adapter approach.
- * <p>
- * The Adapter ({@link GnomeEngineer}) converts the interface of the target class (
+ * 
+ * <p>The Adapter ({@link GnomeEngineer}) converts the interface of the target class (
  * {@link GoblinGlider}) into a suitable one expected by the client ({@link GnomeEngineeringManager}
  * ).
- * 
  */
 public class App {
 
   /**
-   * Program entry point
-   * 
+   * Program entry point.
+   *
    * @param args command line args
    */
   public static void main(String[] args) {
-    Engineer manager = new GnomeEngineeringManager();
+    Engineer manager = new GnomeEngineeringManager(new GnomeEngineer());
     manager.operateDevice();
   }
 }

adapter/src/main/java/com/iluwatar/adapter/GnomeEngineeringManager.java

@@ -1,20 +1,26 @@
 package com.iluwatar.adapter;
 
 /**
- * 
  * GnomeEngineering manager uses {@link Engineer} to operate devices.
- * 
  */
 public class GnomeEngineeringManager implements Engineer {
 
   private Engineer engineer;
 
   public GnomeEngineeringManager() {
-    engineer = new GnomeEngineer();
+
+  }
+
+  public GnomeEngineeringManager(Engineer engineer) {
+    this.engineer = engineer;
   }
 
   @Override
   public void operateDevice() {
     engineer.operateDevice();
   }
+
+  public void setEngineer(Engineer engineer) {
+    this.engineer = engineer;
+  }
 }