Testing Spring Boot Applications Masterclass Workbook

Preface

1. About this eBook
2. Errata & Submitting Feedback
3. Technical Reviewers

Introduction

1. Application Setup
2. Migration to Spring Boot 4
3. Migration to Spring Boot 3
4. Application Walkthrough

Introduction to the Spring Boot Starter Test Dependency

1. Anatomy of the dependency
2. Managing Library Versions
3. Introduction to JUnit 6
4. Introduction to Mockito
5. Additional Test Libraries in Spring Boot Starter Test

The Secret Weapon to Test Your Database Layer: @DataJpaTest

1. Introduction to the JPA Domain Model
2. Start Using @DataJpaTest.
3. Resolving Context Startup Errors
4. Why and When to Use the TestEntityManager
5. Transactional Support
6. Using P6SPY for More Insights
7. Replacing the In-Memory Database
8. Solutions to Pre-Populate Your Database

The Secret Weapon to Test Your Web Layer @WebMvcTest

1. Why Unit Tests Are Not Enough
2. Introduction to @WebMvcTest
3. Defining On Which Level to Mock
4. More Tests for the BookController
5. Advanced Usage
6. Testing the First Secured Endpoint
7. Happy-Path Testing For Creating Reviews
8. Access to Role-Based Secured Endpoints

Testing HTTP Clients Using the RestTemplate

1. Introduction to Testing HTTP Clients
2. The Power of @RestClientTest
3. First Test Using the MockRestServiceServer
4. Test a Failure of the Remote System

Testing HTTP Clients Using the WebClient

1. Required Setup for the MockWebServer
2. Testing the Happy-Path Using the MockWebServer
3. Testing Failure of the Remote System

Testing Business Logic in Isolation

1. Which Logic to Verify
2. Getting the Setup Right for Testing the ReviewService
3. Verify the First Error Scenario
4. Ensure We Don’t Store Reviews With Bad Quality
5. Happy-Path Testing For Storing a Review

Testing a Custom Application Slice

1. Choosing the Application Part for Isolated Testing
2. Introduction to LocalStack
3. Creating a Spring Application Context With Only One Message Listener
4. Understanding the Spring Cloud AWS Auto Configuration
5. Overriding the AWS SQS client
6. Creating a Local SQS Queue and Applying the Configuration
7. Happy-Path Testing for the Whole Listener Process

Remaining Setup to Start the Whole Spring Boot Application

1. What’s Currently Missing to Start the Whole Context
2. First Try to Start the Whole Context
3. Introducing WireMock to Mock HTTP Communication
4. Creating an ApplicationContextInitializer for WireMock
5. Mocking the OpenID Configuration Response
6. Mocking the JWKS (JSON Web Key Set) Response
7. Making Use of the WebTestClient to Access the Backend
8. Creating a Valid JWT to Access Our Endpoints

Writing Integration Tests for Our Application

1. Verifying the Book Synchronization Process
2. Refactor Our WebClient to Mock the HTTP Response
3. Ensure Users Can Create Reviews
4. Develop the Missing API Endpoint Test Driven (TDD)
5. Recap About Integration Tests

Writing Web Tests: Providing The Whole Application Infrastructure

1. What’s Missing Compared to Writing Integration Tests
2. Creating a Web Test Application Profile
3. Using Testcontainers to start the Docker Compose Environment
4. Writing the First Test With Selenide
5. Making Screenshots During Test Execution
6. Further Hints on the Web Test Setup
7. Using Testcontainers With Selenide
8. Recording the Web Test With a Video

Best Practices

1. Spring TestContext Caching

Postface

1. Work With Me
2. Certificate of Completion

Changelog