initial commit for mockito mock methods

mockito/src/test/java/org/baeldung/mockito/MockitoMockTest.java

@@ -0,0 +1,68 @@
+package org.baeldung.mockito;
+
+import static org.mockito.Mockito.*;
+import static org.junit.Assert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.containsString;
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
+
+import org.junit.Test;
+import org.junit.Rule;
+import org.junit.rules.ExpectedException;
+import org.mockito.MockSettings;
+import org.mockito.exceptions.verification.TooLittleActualInvocations;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+
+public class MockitoMockTest {
+    static class CustomAnswer implements Answer<Boolean> {
+        @Override
+        public Boolean answer(InvocationOnMock invocation) throws Throwable {
+            return false;
+        }
+    }
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    @Test
+    public void whenUsingSimpleMock_thenCorrect() {
+        MyList listMock = mock(MyList.class);
+        when(listMock.add(anyString())).thenReturn(false);
+        boolean added = listMock.add(randomAlphabetic(6));
+
+        verify(listMock).add(anyString());
+        assertThat(added, is(false));
+    }
+
+    @Test
+    public void whenUsingMockWithName_thenCorrect() {
+        MyList listMock = mock(MyList.class, "myMock");
+        when(listMock.add(anyString())).thenReturn(false);
+        listMock.add(randomAlphabetic(6));
+        
+        thrown.expect(TooLittleActualInvocations.class);
+        thrown.expectMessage(containsString("myMock.add"));
+
+        verify(listMock, times(2)).add(anyString());
+    }
+
+    @Test
+    public void whenUsingMockWithAnswer_thenCorrect() {
+        MyList listMock = mock(MyList.class, new CustomAnswer());
+        boolean added = listMock.add(randomAlphabetic(6));
+
+        verify(listMock).add(anyString());
+        assertThat(added, is(false));
+    }
+
+    @Test
+    public void whenUsingMockWithSettings_thenCorrect() {
+        MockSettings customSettings = withSettings().defaultAnswer(new CustomAnswer());
+        MyList listMock = mock(MyList.class, customSettings);
+        boolean added = listMock.add(randomAlphabetic(6));
+
+        verify(listMock).add(anyString());
+        assertThat(added, is(false));
+    }
+}