Tag Archives: Function

Legacy Coderetreat: Episode 11 – Extract Class – Code Cast

Extract Class – code cast

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 code cast in Java.

In the previous episodes we restructured some parts of the code base. We also extracted pure functions and applied The Rule of Three when restructuring the code.

Because we have extracted some pure functions, now we need to think if those pure functions belong to new classes. So we structure the functions in a way that they belong together from the point of view of their responsibilities. After structuring the functions we extract the class.

Learn from this video how to extract a class in legacy code in such a way that you do not introduce side-effects to the existing behaviour.

Read here more about this concept in my blog post.

Legacy Coderetreat: Episode 10 – Refactoring the Rule of Three – Code Cast

Refactoring the Rule of Three – code cast

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 code cast in Java.

When refactoring legacy code we need to make sure the structures we extract have a correct meaning. This is why The Rule of Three is very useful: extract to a new structure only when you find an identical duplication three times. Usually we do not have identical duplication, so in that case we need to make the duplication clear, check that it exists three times and only after that perform the extraction.

This code cast will show you also when it is not a good idea to extract a new variable, even if you see it duplicated many times. This is a mechanical kind of refactoring, but reasoning is very important even when we want to get fast by getting mechanical refactorings into our tool bag.

Read here more about this concept in my blog post.

Legacy Coderetreat: Episode 9 – Extract Pure Functions – Code Cast

Extract Pure Functions – code cast

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 code cast in Java.

In the first episode we wrote some characterization tests with the purpose to create a basic safety net. Now we continue to refactor the code, starting from there. We already have some tests running and we want to have methods that do only one thing; we want to apply the Single Responsibility Principle. A really good tool that can help is using pure functions. We extract functions, make them static and then make sure the function does not have any side effects. These functions help me clean the code and help me start structurig the code according to clear responsibilities. At a later time we will extract all these functions that have similar responsibilities to a new class.

Read here more about this concept in my blog post.