initial testing work for mockito configuration of behavior

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

@@ -0,0 +1,60 @@
+package org.baeldung.mockito;
+
+import static org.apache.commons.lang3.RandomStringUtils.randomAlphabetic;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.when;
+
+import org.junit.Test;
+import org.mockito.Mockito;
+
+@SuppressWarnings("unchecked")
+public class MockitoConfigExamplesTest {
+
+    // tests
+
+    @Test
+    public final void whenMockBehaviorIsConfigured_thenBehaviorIsVerified() {
+        final MyList listMock = Mockito.mock(MyList.class);
+        when(listMock.add(anyString())).thenReturn(false);
+
+        final boolean added = listMock.add(randomAlphabetic(6));
+        assertThat(added, is(false));
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public final void givenMethodIsConfiguredToThrowException_whenCallingMethod_thenExceptionIsThrown() {
+        final MyList listMock = Mockito.mock(MyList.class);
+        when(listMock.add(anyString())).thenThrow(IllegalStateException.class);
+
+        listMock.add(randomAlphabetic(6));
+    }
+
+    @Test(expected = NullPointerException.class)
+    public final void whenMethodHasNoReturnType_whenConfiguringBehaviorOfMethod_thenPossible() {
+        final MyList listMock = Mockito.mock(MyList.class);
+        doThrow(NullPointerException.class).when(listMock).clear();
+
+        listMock.clear();
+    }
+
+    @Test
+    public final void givenBehaviorIsConfiguredToThrowExceptionOnSecondCall_whenCallingOnlyOnce_thenNoExceptionIsThrown() {
+        final MyList listMock = Mockito.mock(MyList.class);
+        when(listMock.add(anyString())).thenReturn(false).thenThrow(IllegalStateException.class);
+
+        listMock.add(randomAlphabetic(6));
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public final void givenBehaviorIsConfiguredToThrowExceptionOnSecondCall_whenCallingTwice_thenExceptionIsThrown() {
+        final MyList listMock = Mockito.mock(MyList.class);
+        when(listMock.add(anyString())).thenReturn(false).thenThrow(IllegalStateException.class);
+
+        listMock.add(randomAlphabetic(6));
+        listMock.add(randomAlphabetic(6));
+    }
+
+}