Testing Java Code with JUnit: Bank Account Lifecycle Exercises

Writing reliable unit tests requires more than just asserting outcomes; you must also manage the setup and cleanup of your test state. If your tests share data or interfere with one another, you risk false positives and fragile codebases. By working through a practical bank account example, you will learn how to initialize test data, reset state, and write predictable tests for critical operations like depositing and withdrawing funds. What you'll learn: - Understand the fundamentals of unit testing isolation and why test independence is critical. - Configure test setup and teardown stages using JUnit lifecycle annotations. - Write clean assertions for state-changing methods like deposit and withdraw. - Apply the Arrange-Act-Assert pattern to structure highly readable test cases. - Identify and resolve common test pollution issues where tests accidentally share state. You will start by exploring foundational testing concepts and the JUnit test lifecycle before deep-diving into written code walkthroughs and exercises that build a robust test suite step-by-step. This course is designed for beginner Java developers and QA engineers who want to learn unit testing basics, with no prior testing experience required. Start reading today to write cleaner, more reliable Java tests.