In this module, we will delve into the foundations of unit testing. We'll start with an overview of what unit testing is and the basic concepts behind it. You will then learn about JUnit, a popular tool for unit testing in Java, and see how to write a simple unit test using JUnit. The section continues with detailed explanations of the structure of unit tests, conventions to follow, and the characteristics of proper unit tests. Finally, we will cover the use of assertions in JUnit to validate test results effectively.

In this module, we will guide you through the process of creating a Java project using JUnit. We'll begin by demonstrating how to set up a project using the Maven Quickstart Archetype. Next, you'll learn about the typical structure of a Java project, with a focus on the differences between production and test source trees. Finally, we will cover the essential conventions for creating unit tests, including proper package organization and naming practices, ensuring that your tests are well-organized and easy to maintain.

In this module, we will cover the comprehensive process of writing and running unit tests using JUnit and IntelliJ IDEA. You will learn how to create test methods with the @Test annotation, run these tests within an IDE, and understand the success and failure of tests. We will explore handling exceptions in test failures and the explicit use of Assert.Fail() for validation logic. Additionally, you will be introduced to JUnit's assertions API and the fail-fast test failure mechanism. Finally, we'll delve into best practices like adding descriptive comments to assertions, maintaining DRY principles with @Before, and understanding test fixture instantiation.

In this module, we will explore the use of mock objects and Mockito for unit testing. You'll start by understanding the fundamentals of Mockito and how mock objects are used in testing. We will guide you through configuring projects with Mockito and creating projects that utilize both JUnit and Mockito. The section covers coding and testing various layers of a layered architecture, including the presentation, business, and persistence layers, ensuring proper package organization. Additionally, you'll learn about setting up test fixtures for mock object-based tests and writing specific tests for components like the login controller and authentication service. Finally, we will discuss important design decisions to consider when unit testing your applications.

In this module, we will dive into the Hamcrest Assertions Library and its applications in unit testing. You will begin by evolving domain and repository classes and learning how to ignore tests using the @ignore annotation. We'll cover the implementation of finders in the repository and business logic in the service layer, along with configuring Maven for Java 8. The section includes refactoring practices to develop new services and generating test methods in the IDE. You'll explore JUnit Mockito Runner, @Mock, and @InjectMocks annotations, and learn to analyze production code for effective test writing. We will replace JUnit assertions with Hamcrest assertions, tackle Hamcrest test failures, and create complex assertions using the allOf method and property matchers.