BAEL-2125 - Mockito UnnecessaryStubbingException

testing-modules/mockito-2/src/test/java/com/baeldung/mockito/misusing/ExpectedTestFailureRule.java

@@ -0,0 +1,51 @@
+package com.baeldung.mockito.misusing;
+
+import org.hamcrest.Matchers;
+import org.junit.Assert;
+import org.junit.rules.MethodRule;
+import org.junit.runners.model.FrameworkMethod;
+import org.junit.runners.model.Statement;
+
+public class ExpectedTestFailureRule implements MethodRule {
+
+    private final MethodRule testedRule;
+    private FailureAssert failureAssert = null;
+
+    public ExpectedTestFailureRule(MethodRule testedRule) {
+        this.testedRule = testedRule;
+    }
+
+    @Override
+    public Statement apply(final Statement base, final FrameworkMethod method, final Object target) {
+        return new Statement() {
+            public void evaluate() throws Throwable {
+                try {
+                    testedRule.apply(base, method, target)
+                        .evaluate();
+                } catch (Throwable t) {
+                    if (failureAssert == null) {
+                        throw t;
+                    }
+                    failureAssert.doAssert(t);
+                    return;
+                }
+            }
+        };
+    }
+
+    @SuppressWarnings("unchecked")
+    public void expectedFailure(final Class<? extends Throwable> expected) {
+        FailureAssert assertion = t -> Assert.assertThat(t, Matchers.isA((Class<Throwable>) expected));
+        this.expectedFailure(assertion);
+    }
+
+    private void expectedFailure(FailureAssert failureAssert) {
+        this.failureAssert = failureAssert;
+    }
+
+    @FunctionalInterface
+    private interface FailureAssert {
+        abstract void doAssert(Throwable t);
+    }
+
+}

testing-modules/mockito-2/src/test/java/com/baeldung/mockito/misusing/MockitoUnecessaryStubUnitTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.mockito.misusing;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.lenient;
+import static org.mockito.Mockito.when;
+
+import java.util.ArrayList;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.mockito.exceptions.misusing.UnnecessaryStubbingException;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.quality.Strictness;
+
+public class MockitoUnecessaryStubUnitTest {
+
+    @Rule
+    public ExpectedTestFailureRule rule = new ExpectedTestFailureRule(MockitoJUnit.rule()
+        .strictness(Strictness.STRICT_STUBS));
+
+    @Mock
+    private ArrayList<String> mockList;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+    }
+
+    @Test
+    public void givenUnusedStub_whenInvokingGetThenThrowUnnecessaryStubbingException() {
+        rule.expectedFailure(UnnecessaryStubbingException.class);
+
+        when(mockList.add("one")).thenReturn(true);
+        when(mockList.get(anyInt())).thenReturn("hello");
+
+        assertEquals("List should contain hello", "hello", mockList.get(1));
+    }
+
+    @Test
+    public void givenLenientdStub_whenInvokingGetThenDontThrowUnnecessaryStubbingException() {
+        lenient().when(mockList.add("one"))
+            .thenReturn(true);
+        when(mockList.get(anyInt())).thenReturn("hello");
+
+        assertEquals("List should contain hello", "hello", mockList.get(1));
+    }
+
+}