What strategies can you use to ensure code quality during refactoring?

Ensuring code quality during refactoring hinges on meticulous test case creation. In a recent project, we faced a critical authentication module refactor. Before any changes, we crafted comprehensive test cases covering user scenarios and edge cases. These tests not only validated existing functionality but also served as benchmarks for refactored code. With thorough testing, we refactored confidently, knowing tests would catch any unintended side effects, ensuring a seamless transition.

Refactoring can be a nightmare when there are not enough tests or worse no tests at all. A strategy is to start adding very detailed integration tests for projects that have little to no tests. They are often the only tests that can be written when the code complexity is that high that unit tests are not applicable. Having integration tests as a basis, start slowly your refactoring and ensure the new code is as testable as possible by unit tests.

From my point of view code coverage unit test cases play a major role, who is the person going to do the refactoring the existing code those persons have good knowledge on what are the dependent areas that may effect. 1. We need to identify the dependent modules/areas 2. Write the unit test cases to cover the dependent modules

In my view, code reviews are crucial for maintaining code quality during refactoring. Pull requests are the ultimate and best way to review code, and after a successful review, we can merge it.

Automation scripts thrive on peer review! Fresh eyes catch errors & spark efficiency improvements. It's a win-win for code quality & team knowledge.

Here's a tip to making small changes: - identify an area of improvement - change only the code that is needed for it - ignore any other issues you spot (write a TODO in case you want to mark something else that you have spotted) - test that change; negative, positive, edge case - commit and push that change. Then and only then start looking at another area of improvement. This way you won't have to dive into the rabbit hole when fixing one small thing.

VS Code has a lot of features that support code refactoring out of the box: Extract method, extract variable, rename symbol, refactor preview panel (to know how your changes would look once applied), global find and replace, code actions - they give you tips on what to refactor and also let you act on those tips with a single click. IntelliJ has a much wider variety of refactoring options available but it is a paid software.

Documenting changes is essential during refactoring. Updating or creating documentation, such as inline comments and README files, helps team members understand the rationale behind changes and how the current code structure works. This clarity is especially helpful for onboarding new developers or revisiting the code later.

The goal of refactoring is not just to clean up the code but also to make it easier for future development and maintenance. It's important to plan, execute carefully, and test thoroughly to ensure that refactoring improves the code without introducing new issues. Here are some other strategies that can help: >> Simplifying Methods: Break down large methods into smaller. Simplify complex methods by reducing parameters, removing redundant code, and improving logic flow.This improves readability and maintainability. >> Collaborate with Testers: Engage with the QA team to ensure that refactoring doesn't introduce new bugs. >> Prioritize code duplication: Remove duplicate code to improve the codebase's DRY principle adherence.

When refactoring code adopt a Nevernest strategy. More than 3 indentations of code is difficult to read and logically goes against single responsibility functions. Inversion or extraction of long verbose functions that do everything will make your code easier to test and read in the long run. Old codebases that need refactoring are the best playground for Nevernesting.