/* * Copyright (c) 2016 Mockito contributors * This program is made available under the terms of the MIT License. */ package org.mockito.exceptions.misusing; import org.mockito.Mockito; import org.mockito.quality.Strictness; import org.mockito.exceptions.base.MockitoException; import org.mockito.junit.MockitoRule; /** * Strict stubbing is a new feature introduced in Mockito 2.3. * Detecting potential stubbing problems is intended to help writing and debugging tests. * The {@code org.mockito.exceptions.misusing.PotentialStubbingProblem} exception is thrown when a mock method is stubbed with argument X in test but then invoked with argument Y in code. * Example: * <pre class="code"><code class="java"> * //test method: * given(mock.getSomething(100)).willReturn(something); * * //code under test: * Something something = mock.getSomething(50); // <-- stubbing argument mismatch * </code></pre> * The stubbing argument mismatch typically happens in following use cases: * <ol> * <li>Mistake or typo in the test code, the argument(s) used when declaring stubbings is unintentionally different</li> * <li>Mistake or typo in the code under test, the argument(s) used in the code under test is unintentionally different</li> * <li>Intentional use of stubbed method with different argument, either in the test (more stubbing) or in code under test</li> * </ol> * This exception is very useful for 95% of the cases (use cases 1 and 2). * However, it can give false negative signal for 5% of the cases (use case 3). * It is a trade-off for better debuggability and productivity of the typical cases. * <p> * What to do if you fall into use case 3? You have 2 options: * <ol> * <li>Do you see this exception because you're stubbing the same method multiple times in the test? * In that case, please use {@link org.mockito.BDDMockito#willReturn(Object)} or {@link Mockito#doReturn(Object)} * family of methods for stubbing. * Good looking stubbing via {@link Mockito#when(Object)} has its drawbacks: the framework cannot distinguish between * actual invocation on mock and the stubbing attempt in the test. * Hence the need to use {@link org.mockito.BDDMockito#willReturn(Object)} or {@link Mockito#doReturn(Object)} for certain edge cases. * </li> * <li>Reduce the strictness level in the test method: * <pre class="code"><code class="java"> * public class ExampleTest { * @Rule * public MockitoRule rule = MockitoJUnit.rule().strictness(Strictness.STRICT_STUBS); * * @Test public void exampleTest() { * //Change the strictness level only for this test method: * mockito.strictness(Strictness.LENIENT); * * //remaining test code * } * } * </code></pre> * </li> * <li>In Mockito 2.x, simply don't use {@link MockitoRule#strictness(Strictness)} with {@link Strictness#STRICT_STUBS} for that test. * You will lose stubbing strictness but at least you can complete the test.</li> * </ol> * <p> * We are very eager to hear feedback about "strict stubbing" feature, let us know by commenting on GitHub * <a href="https://github.com/mockito/mockito/issues/769">issue 769</a>. * Strict stubbing is an attempt to improve testability and productivity with Mocktio. Tell us what you think! * * @since 2.3.0 */ public class PotentialStubbingProblem extends MockitoException { public PotentialStubbingProblem(String message) { super(message); } }