Unit Testing with JUnit
Course Code: JUNIT
Duration: 3 days
Unit Testing with JUnit Course Overview
JUnit is the most popular and widely used Java unit testing framework.
This hands-on course, delivered using JUnit v5, comprises sessions dealing with unit testing, setup, annotations, assertions and assumptions, conditional tests, parameterised tests, stubbing and mocking, Mockito, DAO and Servlet testing, testing multi-threaded code, and TDD.
Exercises and examples are used throughout the course to give practical hands-on experience with the techniques covered.
Course Objectives
This course aims to provide the delegate with the knowledge to be able to design and code good quality, isolated unit tests with JUnit that exploit all the features of the JUnit framework.
Who will the Course Benefit?
This Unit Testing with JUnit course will benefit Java developers and testers who are new to JUnit and/or unit testing more generally.
Skills Gained
The delegate will learn and acquire skills as follows:
- Define unit testing and describe the structure of a test
- List some guidelines for writing good quality unit tests
- Install JUnit
- Code a JUnit test class
- List and describe the primary JUnit annotations
- Select the most appropriate assert method for the task at hand
- Code conditional tests
- Code parameterised tests
- Describe the purpose of and difference between stubbing and mocking
- Exploit Mockito to perform stubbing and mocking
- Code tests for IO methods and DAOs
- Describe how to deal with the testing of Servlets
- Test multi-threaded code
- Describe the principles of TDD
Unit Testing with JUnit Training Course
Course Introduction
- Administration and Course Materials
- Course Structure and Agenda
- Delegate and Trainer Introductions
Session 1: UNIT TESTING
- What is unit testing
- The purpose of unit testing
- Terminology
- The structure of a test
- Assertions
- Code coverage
- Guidelines for writing good unit tests
- Other types of testing
Session 2: GETTING STARTED WITH JUNIT
- What is JUnit
- The main features of JUnit
- JUnit in IntelliJ
- JUnit with Maven/Gradle
- A simple unit test
- Alternatives to JUnit
Session 3: ANNOTATIONS
- @Test
- @BeforeEach
- @AfterEach
- @BeforeAll
- @AfterAll
- @TestMethodOrder
- @TestInstance
- @DisplayName
- @Disabled
- @Timeout
- @ExtendWith
Session 4: ASSERTIONS & ASSUMPTIONS
- assertEquals
- assertTrue/False
- assertNull
- assertThrows
- assertArrayEquals
- assertIterableEquals
- assertLinesMatch
- assertSame
- assertInstanceOf
- assertTimeout
- assertNot*
- assertAll
- fail
- assumeTrue/False
- assumingThat
Unit Testing with JUnit Training Course
Session 5: CONDITIONAL TESTS
- OS conditions
- CRE conditions
- System property conditions
- Environment variable conditions
- Custom conditions
Session 6: PARAMETERISED TESTS
- What is a parameterised test
- The junit-jupiter-params artefact
- @ParameterizedTest
- Consuming arguments
- Argument sources
- Argument conversion
- Argument aggregation
- Customising display names
Session 7: STUBS, MOCKS, & PROXIES
- Dependencies
- Test doubles/fake objects
- Stubs
- Mocks
- Proxies
Session 8: MOCKITO
- What is Mockito
- The mockito-core and mockito-junit-jupiter artefacts
- The Mockito JUnit extension
- Creating a mock/spy
- Setting expectations (when, then)
- Argument matchers
- Verifying behaviour
- Spying
- Annotations
- Mocking static methods
Unit Testing with JUnit Training Course
Session 9: IO, DAO, & SERVLET TESTING
- Testing methods that use IO streams
- Testing DAOs by rolling back transactions
- Moving business logic out of the Servlet to simplify testing
Session 10: TESTING MULTI-THREADED CODE
- Sharing data among threads (a review)
- The difficulty in testing concurrent applications
- Testing the code with one thread
- Testing the code with many threads
- @RepeatedTest
- The problem with non-deterministic tests
- 3rd-party libraries
- Best practices
Session 11: TEST-DRIVEN DEVELOPMENT (TDD)
- What is TDD
- The pros and cons of TDD
- The three rules
- The red green refactor lifecycle
- Course technical content is subject to change without notice.
- Course content is structured as sessions, this does not strictly map to course timings. Concepts, content and practicals often span sessions.
Requirements
Delegates attending this course should be familiar with basic programming concepts and have some experience coding with Java at least. Ideally delegates will be competent Java developers who have a good understanding of OO principles and are able to build simple applications that exploit APIs including Collections, IO, and JDBC. This knowledge can be obtained by attendance on the pre-requisite Java Programming 1 / Java Developer course.
JUnit 5 exploits modern Java features including lambda expressions. Some experience or familiarity with such features, therefore, is desirable. These skills can be obtained by attendance on the Java Programming 2 / Java Advanced Developer course.
Pre-Requisite Courses
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