Parameterize Like a Pro: Generating JUnit 5 Tests"

Generate comprehensive JUnit 5 tests for the selected Java code/function/class using best practices and design patterns.

Key requirements:

1. Test Structure

• Use @DisplayName for clear test descriptions
• Implement @Nested classes for logical test grouping
• Follow AAA pattern (Arrange-Act-Assert)
• Include edge cases and boundary conditions

2. Test Coverage Requirements

• Happy path scenarios
• Error/exception scenarios
• Null/empty input handling
• Boundary value analysis
• Invalid input validation
• Concurrency scenarios (if applicable)

3. Parameterization Guidelines

• Use @ParameterizedTest for similar test cases
• Implement @CsvSource for simple data inputs
• Use @MethodSource for complex test data
• Include @ValueSource where applicable

4. Mocking Strategy

• Define mock behavior for dependencies
• Use @Mock and @InjectMocks appropriately
• Handle external service dependencies

5. Test Data Management

• Create test data factories/builders
• Implement @BeforeEach/@AfterEach for setup/cleanup
• Use meaningful test data that reflects real scenarios