Add junit-mockito module: 30 runnable JUnit 6.1.3 / Mockito 5.24.0 interview answers

One test per question, each writing and asserting its own transcript under output/. Covers lifecycle, extensions, parameterized and dynamic tests, mocks vs spies, verification, strict stubs, static and constructor mocking, and flaky tests. Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01CifR2BE7PBvRy5hT8TS9oz
2026-10-26 01:52:44 +00:00
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+package lab.jm;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockConstruction;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.when;
+
+import java.io.InputStream;
+import java.util.concurrent.atomic.AtomicReference;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedConstruction;
+import org.mockito.MockedStatic;
+
+/** Q24 to Q26: final classes, static mocking, constructor mocking. */
+class E_MockitoAdvancedTest extends Lab {
+
+    @Test
+    void q24_finalClassesAndMockMaker() throws Exception {
+        q(24, "final-classes-mock-maker");
+        FinalPricer pricer = mock(FinalPricer.class);
+        when(pricer.price(3)).thenReturn(999);
+        p("FinalPricer is final: %s", java.lang.reflect.Modifier.isFinal(FinalPricer.class.getModifiers()));
+        p("mock(FinalPricer.class).price(3) = %d (real code would give 30)", pricer.price(3));
+        p("mock.getClass() == FinalPricer.class : %s", pricer.getClass() == FinalPricer.class);
+        var maker = org.mockito.internal.configuration.plugins.Plugins.getMockMaker();
+        p("default MockMaker : %s", maker.getClass().getName());
+        int major;
+        try (InputStream in = org.mockito.Mockito.class.getResourceAsStream("Mockito.class")) {
+            byte[] head = in.readNBytes(8);
+            major = ((head[6] & 0xff) << 8) | (head[7] & 0xff);
+        }
+        p("class-file major version of org.mockito.Mockito : %d (Java %d)", major, major - 44);
+        assertEquals(999, pricer.price(3));
+        assertTrue(pricer.getClass() == FinalPricer.class);
+        assertTrue(maker.getClass().getSimpleName().contains("Inline"));
+        assertEquals(55, major);
+    }
+
+    @Test
+    void q25_mockStatic() throws Exception {
+        q(25, "mock-static");
+        p("before            : %s", Ids.newOrderId());
+        AtomicReference<String> otherThread = new AtomicReference<>();
+        try (MockedStatic<Ids> ids = mockStatic(Ids.class)) {
+            ids.when(Ids::newOrderId).thenReturn("MOCK-ID");
+            p("inside the scope  : %s", Ids.newOrderId());
+            Thread t = new Thread(() -> otherThread.set(Ids.newOrderId()));
+            t.start();
+            t.join();
+            p("other thread sees : %s", otherThread.get());
+            ids.verify(Ids::newOrderId, org.mockito.Mockito.times(1));
+        }
+        p("after the scope   : %s", Ids.newOrderId());
+        assertEquals("REAL-ID", otherThread.get());
+        assertEquals("REAL-ID", Ids.newOrderId());
+    }
+
+    @Test
+    void q26_mockConstruction() {
+        q(26, "mock-construction");
+        p("before : %s", Receipt.print("tea"));
+        try (MockedConstruction<Receipt> mc = mockConstruction(Receipt.class,
+                (mock, ctx) -> when(mock.render()).thenReturn("FAKE " + ctx.arguments()))) {
+            p("inside : %s", Receipt.print("tea"));
+            p("constructed during the scope: %d", mc.constructed().size());
+            assertEquals(1, mc.constructed().size());
+        }
+        p("after  : %s", Receipt.print("tea"));
+        assertFalse(Receipt.print("tea").startsWith("FAKE"));
+    }
+}