Monthly Archives: May 2015

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Legacy Coderetreat: Part 15 – Refactor Conditionals by Explaining Variable

Refactor conditionals: Explain Variable

Blog post series

This blog post is part of a series about legacy coderetreat and legacy code techniques you can apply during your work. Please click to see more sessions about legacy code. Refactor Conditionals - Explain Variable

Purpose

When you try to read a code base that has many conditionals, often the problem is that the condition itself is very hard to understand. This technique improves the conditionals by making them clear and very easy to read. Read More →

Legacy Coderetreat: Episode 13 – Document Possible Bugs with Tests – Codecast

Document Possible Bugs with Tests – Codecast

Blog post series

This blog post is part of a series about legacy coderetreat and legacy code techniques you can apply during your work. Please click to see more sessions about legacy code.

Code Cast

This is a codecast in Java.

In the previous episodes we reach the moment when we extracted one simple class. We used the The Rule of Three and pure functions. This newly extracted class is covered with characterization tests. Then we wrote some unit tests in the following episode. But some of the behavious seemed strange, and we thought they might be bugs.

Because we are never sure when working on existing code if some behavior is a bug or a feature, we want to document all the suspicious cases. In order to do that, I am presenting three methods: use an annotation, prefix the test, use a different class.

Bug or feature? Check out the codecast to see all of them in action.

Read here more about this concept in my blog post.

When we document defects with tests it is a good idea to group all the tests documenting possible bugs one after the other. The discussions with the business persons are easier and you do not need to search the next test again and again.

Always discuss with business persons before changing the code. Often one might think they understand what the code does, but the situation if often very different in practice. Think to verify every detail with business analysts before changing the existing code.

Legacy Coderetreat: Episode 12 – Unit Testing on Legacy Code – Codecast

Unit Testing on Legacy Code – Codecast

Blog post series

This blog post is part of a series about legacy coderetreat and legacy code techniques you can apply during your work. Please click to see more sessions about legacy code.

Codecast

This is a codecast in Java.

In the previous episodes we reach the moment when we extracted one simple class. We used the The Rule of Three and pure functions. This newly extracted class is covered with characterization tests. But that is not enough, we want to continue adding other types of tests to understand the system better.

This is why during this episode you will see how to add unit tests to code extracted from a legacy code class. These tests have a small granularity level than the characterization tests we already have. This is the moment to dive more into details.

See this video to understand how you can document the current state of the system, by unit testing on legacy code.

Read here more about this concept in my blog post.

We started with a class having non-public methods. The purpose of this session was to start covering the class with tests. In this moment we have short and clear unit tests, written in isolation of any slow dependencies. These tests are fast and we need to run then any time we will change the production code, to make sure we do not introduce defects.

In the same way as shown in the last blog posts, we can extract pure functions, extract classes and then cover these classes with unit tests.