JUnit 5 Training Overview
JUnit 5 is substantively different than JUnit 4. Although the core testing principles are the same, there are substantial implementation differences, important new features, and a brand new extension model.
Accelebrate's Java Testing with JUnit 5 teaches experienced Java developers the fundamentals of unit testing using JUnit 5 and Mockito libraries. Attendees learn how to test enterprise components in the persistence, service, and web layers. Best practices are emphasized and demonstrated throughout this course.
Location and Pricing
Accelebrate offers instructor-led enterprise training for groups of 3 or more online or at your site. Most Accelebrate classes can be flexibly scheduled for your group, including delivery in half-day segments across a week or set of weeks. To receive a customized proposal and price quote for private corporate training on-site or online, please contact us.
In addition, some courses are available as live, instructor-led training from one of our partners.
Objectives
- Understand the new JUnit 5 library structure, role of each component, and how they interact
- Configure IDE projects to run tests natively, and via Maven Surefire
- Write cohesive and effective tests and design classes for testability
- Understand the full test lifecycle, and employ it to configure test fixtures
- Run tests using all available mechanisms: IDE, Maven, JUnit Console Launcher, Launcher API
- Use test discovery and filtering to define and run test plans, including conditional test execution
- Employ naming conventions at every level - test name, classname, display name
- Organize tests with assertion groups and nested tests
- Use test interfaces to apply good OO principles to testing
- Understand the new JUnit extension model, and how to write and use them
- Understand JUnit 4 compatibility and migration
- Use mock objects with Mockito to support isolated testing
- Explore Mockito's facilities for dependency injection of mocks
- Use argument matchers for more generalized testing with mocks
- Implement partial mocking with spies
- Understand the issues in testing enterprise components
- Understand the two basic approaches: standalone testing with mocks, and in-container testing
- Test database access components, using both fakes and an embedded database
- Understand the additional issues involved in testing
Prerequisites
All students must have a good working knowledge of Java and OO, including the use of interfaces, abstract classes, collections, factories, and generics. Experience with Java 8 lambda expressions is helpful, but not required.
Outline
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Introduction
Unit Testing with JUnit 5
- Overview
- Unit Testing and JUnit Overview
- New Features in JUnit 5
- JUnit 5 Library Components
- Naming Conventions and Organizing Tests
- Tests and Assertions
- Writing Test Methods
- Assertions
- Assertion Messages
- Test Fixtures and Test Lifecycle
- Creating and Using Text Fixtures
- Test Run Lifecycle: @BeforeEach and @AfterEach, @BeforeAll and @AfterAll
- Controlling Test Instances
Writing and Running Tests (includes a brief primer on Java 8 new features)
- Additional Testing Needs
- Testing for Exceptions
- Setting Timeouts
- Assertion Groups
- Running Test
- IDE Support: Eclipse, IntelliJ IDEA
- Maven Configuration
- JUnit Platform Console Launcher
- Launcher API
- Test Discovery and Selection
- Display Names
- Grouping and Filtering with Tags
- Configuration Parameters
- Nested Tests
- Advanced Capabilities
- Custom Composed Annotations
- Inheritance with Test Classes
- Extensions
- Conditional Test Execution
- Parameterized Tests
- JUnit 4 Migration
- The Do-Nothing Case
- Using a JUnit 4 Runner
- API Changes
- JUnit 4 Runners and Rules
- JUnit 4 Test Suites
- Best Practices
- Testing Void and Private Methods
- Test Cohesion and Assertion Scope
- Characteristics of Good Tests
- Writing Testable Code
- Testing Anti-Patterns
Testing with Mocks
- Overview
- Mock Objects as Collaborators
- Mockito Overview
- Creating and Using Mocks
- Basic Steps in Mocking
- The Mockito Class
- Mock Creation with @Mock
- JUnit 5 MockitoExtension
- Stubbing
- Additional Capabilities
- Argument Matchers
- Partial Mocking with Spies
- Mocking the Unmockable
- Dependency Injection of Mocks
Testing Enterprise Components
- Overview
- Unit Testing vs. Integration Testing
- Testing with Mocks vs. In-Container Testing
- Mocks vs. Fakes
- Testing the Persistence Layer
- Database Options: Installed, Embedded, Embedded-in-Memory
- Standalone vs. In-Container Testing
- Test Independence and Transaction Rollback
- In-Container Testing with Arquillian [Overview]
- Testing Services
- Similar Issues, Different Layer
- Working with External Resources
- The Argument for In-Container Testing
- Testing Web Components
- Interfacing with External Clients
- Difficulties in Standalone Testing with Mocks
- Manual vs. Automated Testing
- Automated Testing with Selenium [Overview]
Conclusion
Training Materials
All JUnit 5 training students receive comprehensive courseware.
Software Requirements
- A recent version of Windows, macOS, or Linux with at least 8 GB RAM
- JDK 8 or later
- Eclipse or IntelliJ IDEA
- Other free software - please contact us if you have purchased this class
