This is the Java-only version of the kata from https://github.com/christianhujer/expensereport. The relevant parts of the README are below.
I've updated it to the latest JUnit, added the AssertJ assertion library, and bumped the Java version to 17. I also split the classes/enums into separate files and added a starter test method.
You might try using Arlo Belshee's Commit Notation and make the smallest commits you can. See https://github.com/RefactoringCombos/ArlosCommitNotation/blob/main/Learning%20Path.md on how to get started.
The ExpenseReport legacy code refactoring kata in various languages.
This is an example of a piece of legacy code with lots of code smells. The goal is to support the following new feature as best as you can:
- Add Lunch with an expense limit of 2000.
- 📚 Read the code to understand what it does and how it works.
- 🦨 Read the code and check for design and code smells. Make a list of all code and design smells that you find.
- 🧑🔬 Analyze what you would have to change to implement the new requirement without refactoring the code.
- 🧪 Write a characterization test. Expand your list of code and design smells. Add those smells that you missed earlier and discovered now because they made your life writing a test miserable.
- 🔧 Refactor the code.
- 🔧 Refactor the test.
- 👼 Test-drive the new feature.
- Make sure that all languages are providing the identical challenge. To be practical, this will require the removal of the timestamp side-effect.
- Provide the time-stamp side-effect on a separate branch.
- Provide a test setup (without test) on a separate branch so that folks can choose whether they want to include the setup work in the kata or not.
- Provide a level 2 challenge for creating an HTML report besides the Plain Text report.
I first encountered the ExpenseReport example during a bootcamp at Equal Experts. I also have seen the ExpenseReport example being used by Robert "Uncle Bob" C. Martin. However, he seems to not be the original author (https://twitter.com/unclebobmartin/status/1537063143326855176?s=20&t=lh_vVb9jUQmY6PYG50974w) I have tried to research its origins but so far I have failed. If you know who has first come up with this example, please get in touch with me.