Tag Archives: Test

Legacy Coderetreat: Episode 13 – Document Possible Bugs with Tests – Code Cast

Document Possible Bugs with Tests – 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 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 behaviours seemed strange, and we thought they might be bugs.

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

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

Read here more about this concept in my blog post.

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

Unit Testing on Legacy Code – 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 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.

Legacy Coderetreat: Part 14 – Document possible Defects with tests

Document possible Defects with Tests

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.

Purpose

When writing unit tests on legacy code, we often discover behaviours of the system that seem wrong. The main rule is: DO NOT change the production code without being absolutely sure that the change does not introduce defects. Instead we need to mark all the tests that characterize a possible defective behaviour. Let’s look at some ways to document possible defects with tests.

Document Possible Defects with Tests

Document Possible Defects with Tests

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Legacy Coderetreat: Part 9 – Use Mocking Framework

Use Mocking Framework

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.

Purpose

By using mocking frameworks we are writing short and easy to read tests. The duplication of test doubles written by hand is minimized by the use mocking framework.

mocking-framework

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Legacy Coderetreat: Part 8 – Extract and Override

Extract and Override

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.

Purpose

Almost always when needing to test existing code we bump against dependencies that make the system untestable. This technique is useful to extract the static dependencies. After that we can use dependency inversion in order to be able to really test the systems.

With this technique we can transform untestable systems into testable systems, step by step. The steps are small because we want to enable safety while changing the code.

Extract and Override

Extract and Override

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