Finished normal Mockito testing codes.

JustPractice/java/javamockito/src/main/org/mewx/practice/javamockito/ServiceCaller.java

@@ -3,7 +3,9 @@
 import java.util.List;
 
 public class ServiceCaller {
+    private Service service = new Service();
+
     public void callService(List<String> list, Message messageHost) {
-        new Service().runService(list, messageHost);
+        service.runService(list, messageHost);
     }
 }

JustPractice/java/javamockito/src/test/org/mewx/practice/javamockito/ServiceCallerTest.java

@@ -0,0 +1,55 @@
+package org.mewx.practice.javamockito;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.*;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.Assert.*;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+@RunWith(MockitoJUnitRunner.class)
+public class ServiceCallerTest {
+    @InjectMocks
+    private ServiceCaller serviceCaller = new ServiceCaller();
+    @Spy
+    private Service serviceInside = new Service(); // NOTE: cannot apply to new Service() objects inside methods // TODO: try PowerMockito
+    @Captor
+    private ArgumentCaptor<List<String>> argCaptor;
+
+    private Message message;
+    private ArrayList<String> list;
+
+    @Before
+    public void setUp() {
+        // Note: for JUnit 4.5+, no need to initMocks() any more
+        message = new Message();
+        list = new ArrayList<>();
+        list.add("Initial item");
+    }
+
+    @Test
+    public void callServiceWithOneInList() {
+        serviceCaller.callService(list, message);
+        verify(serviceInside, times(1)).runService(argCaptor.capture(), eq(message));
+        assertEquals(1, argCaptor.getValue().size());
+        assertEquals(1, message.getSize());
+        assertEquals(Service.ERROR_MSG, message.getMessageAt(0));
+    }
+
+    @Test
+    public void callServiceWithTwoInList() {
+        list.add("Another item");
+
+        serviceCaller.callService(list, message);
+        verify(serviceInside, times(1)).runService(argCaptor.capture(), eq(message));
+        assertEquals(2, argCaptor.getValue().size());
+        assertEquals(0, message.getSize());
+    }
+}