studying step17

Frank Oh · Frank Oh · commit e521c8039ab0 · 2019-01-31T15:47:19.000+09:00
diff --git a/mockito-unit-test/src/test/java/in28minutes/powermock/PowerMockitoMockingConstructorTest.java b/mockito-unit-test/src/test/java/in28minutes/powermock/PowerMockitoMockingConstructorTest.java
@@ -0,0 +1,42 @@
+package in28minutes.powermock;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.powermock.api.mockito.PowerMockito;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import java.util.ArrayList;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.stub;
+
+@RunWith(PowerMockRunner.class)
+@PrepareForTest({ SystemUnderTest.class /*To be able to mock the Constructor, we need to add in the Class that creates the new object*/ })
+public class PowerMockitoMockingConstructorTest {
+
+	private static final int SOME_DUMMY_SIZE = 100;
+
+	@Mock
+	Dependency dependencyMock;
+
+	@InjectMocks
+	SystemUnderTest systemUnderTest;
+
+	@Test
+	public void powerMockito_MockingAConstructor() throws Exception {
+
+		ArrayList<String> mockList = mock(ArrayList.class);
+
+		stub(mockList.size()).toReturn(SOME_DUMMY_SIZE);
+
+		PowerMockito.whenNew(ArrayList.class).withAnyArguments().thenReturn(mockList);
+
+		int size = systemUnderTest.methodUsingAnArrayListConstructor();
+
+		assertEquals(SOME_DUMMY_SIZE, size);
+	}
+}
