#BAEL-8669: add main source

Author: hmdrzsharifi

testing-modules/junit-5/pom.xml

@@ -125,6 +125,8 @@
                     <argLine>
                         --add-opens java.base/java.lang=ALL-UNNAMED
                         --add-opens java.base/java.time=ALL-UNNAMED
+                        --add-opens java.base/java.time.format=ALL-UNNAMED
+                        --add-opens java.base/java.util=ALL-UNNAMED
                     </argLine>
                 </configuration>
             </plugin>

testing-modules/junit-5/src/main/java/com/baeldung/mockfinal/FinalList.java

@@ -0,0 +1,10 @@
+package com.baeldung.mockfinal;
+
+public final class FinalList extends MyList {
+
+    @Override
+    public int size() {
+        return 1;
+    }
+
+}

testing-modules/junit-5/src/main/java/com/baeldung/mockfinal/MyList.java

@@ -0,0 +1,25 @@
+package com.baeldung.mockfinal;
+
+import java.util.AbstractList;
+
+public class MyList extends AbstractList<String> {
+
+    @Override
+    public String get(final int index) {
+        return null;
+    }
+
+    @Override
+    public int size() {
+        return 1;
+    }
+
+    @Override
+    public void add(int index, String element) {
+        // no-op
+    }
+
+    final public int finalMethod() {
+        return 0;
+    }
+}

testing-modules/junit-5/src/test/java/com/baeldung/mockfinal/PowerMockFinalsUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.mockfinal;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.powermock.api.mockito.PowerMockito;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+import static org.powermock.api.mockito.PowerMockito.when;
+
+@RunWith(PowerMockRunner.class)
+@PrepareForTest({MyList.class, FinalList.class})
+public class PowerMockFinalsUnitTest {
+
+    @Test
+    public void whenMockFinalMethod_thenMockWorks() throws Exception {
+        MyList mockClass = PowerMockito.mock(MyList.class);
+        when(mockClass.finalMethod()).thenReturn(1);
+
+        assertThat(mockClass.finalMethod()).isNotZero();
+    }
+
+    @Test
+    public void whenMockFinalClass_thenMockWorks() throws Exception {
+        FinalList mockClass = PowerMockito.mock(FinalList.class);
+        when(mockClass.size()).thenReturn(2);
+
+        assertThat(mockClass.size()).isNotEqualTo(1);
+    }
+
+}