mockito exceptions

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

@@ -0,0 +1,57 @@
+package org.baeldung.mockito;
+
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import org.junit.Test;
+import org.mockito.Mockito;
+
+public class MockitoExceptionIntegrationTest {
+
+    @Test(expected = NullPointerException.class)
+    public void whenConfigNonVoidRetunMethodToThrowEx_thenExIsThrown() {
+        MyDictionary dictMock = mock(MyDictionary.class);
+        when(dictMock.getMeaning(anyString())).thenThrow(NullPointerException.class);
+
+        dictMock.getMeaning("word");
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void whenConfigVoidRetunMethodToThrowEx_thenExIsThrown() {
+        MyDictionary dictMock = mock(MyDictionary.class);
+        doThrow(IllegalStateException.class).when(dictMock)
+            .add(anyString(), anyString());
+
+        dictMock.add("word", "meaning");
+    }
+
+    @Test(expected = NullPointerException.class)
+    public void whenConfigNonVoidRetunMethodToThrowExWithNewExObj_thenExIsThrown() {
+        MyDictionary dictMock = mock(MyDictionary.class);
+        when(dictMock.getMeaning(anyString())).thenThrow(new NullPointerException("Error occurred"));
+
+        dictMock.getMeaning("word");
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void whenConfigVoidRetunMethodToThrowExWithNewExObj_thenExIsThrown() {
+        MyDictionary dictMock = mock(MyDictionary.class);
+        doThrow(new IllegalStateException("Error occurred")).when(dictMock)
+            .add(anyString(), anyString());
+
+        dictMock.add("word", "meaning");
+    }
+
+    // =====
+
+    @Test(expected = NullPointerException.class)
+    public void givenSpy_whenConfigNonVoidRetunMethodToThrowEx_thenExIsThrown() {
+        MyDictionary dict = new MyDictionary();
+        MyDictionary spy = Mockito.spy(dict);
+
+        when(spy.getMeaning(anyString())).thenThrow(NullPointerException.class);
+        spy.getMeaning("word");
+    }
+}