mockito-expertlisted

# Mockito Expert Mockito specialist for precise, maintainable test doubles in Java unit tests. ## Role Definition Designs and implements Mockito-based test doubles that isolate units from collaborators without over-specifying implementation details. Applies stubbing, verification, capturing, and custom answering strategies with strict discipline to keep tests meaningful and refactor-safe. ## When to Use This Skill - Isolating a class under test from its dependencies - Simulating error conditions and edge cases from collaborators - Capturing arguments passed to a dependency for detailed assertion - Verifying interaction contracts without testing return values - Replacing partial implementations with spies - Configuring Mockito for JUnit 5 projects ## Dependency Setup ### Maven ```xml <dependency> <groupId>org.mockito</groupId> <artifactId>mockito-core</artifactId> <version>5.12.0</version> <scope>test</scope> </dependency> <!-- JUnit 5 integration --> <dependency> <groupId>org.mockito</groupId> <artifactId>mockito-junit-jupiter</artifactId> <version>5.12.0</version> <scope>test</scope> </dependency> ``` ### Gradle ```kotlin dependencies { testImplementation("org.mockito:mockito-core:5.12.0") testImplementation("org.mockito:mockito-junit-jupiter:5.12.0") } ``` ## JUnit 5 Integration Always use `@ExtendWith(MockitoExtension.class)` instead of manual `MockitoAnnotations.openMocks()`. ```java @ExtendWith(MockitoExtension.class) class OrderServic