What are the benefits of adding automated tests during code refactoring?

I would go a bit further than "Early Detection" though that is nice, but just "Detection!". The whole point of refactoring is to make "Behaviour-preserving changes", how can we tell if a change is "Behaviour preserving"? We could rely on our god-like skills and intuition (in case you couldn't tell, that was my English version of sarcasm) or MUCH, MUCH better than that, we can test. The most efficient and best way to test, certainly in support of refactoring, is to use automated testing, because once we have done the work of writing them, we can use them over and over again.

this would help testers to find bugs hidden in the complex scenarios instead of spending time verifying the happy flow of the software.

--> Memory Intact Saving Data snapshots before, and then validating post refactoring, gives reassurance on the data being intact. Automating Read Only APIs is one of the many ways to ensure legacy data integrity. --> Look forward and Write Once the Read Only is certified, automated testing, dealing with write operations, ensures me that user interactions are landing in the right DB, in the right schema, within the right table, in the right column with the right value. --> Is and Was It keeps me informed whether the software "is" functioning exactly as it "was", by scrutinizing the critical flows, looking for flaws.

Adding automation test during code refactoring provides added confidence in the code, helps in maintainance of regression test scripts and we can identify bugs early on the process, enabling faster feedback loop

Run all automated tests (change the location of the ID for the tested objects); Performing other technical work that is required after the refactoring process (using Selenium or any other testing tool). Also, we can make the following groups to see why?software?QA engineers should be familiar with code refactoring: Unit testers/developers benefit from code refactoring as it involves upgrading old CSS classes and adding new program code. New unit tests appear while old ones are not executed. Testers perform exhaustive and?regression testing during code refactoring. This includes functional checks for all potential user groups. For example, in an online shop, testing involves the behavior of shop assistants and customers.

Automated tests during code refactoring offer faster feedback on code changes. They quickly detect regressions or unintended consequences of refactoring, ensuring the code maintains its functionality. This immediate feedback loop accelerates the refactoring process, enabling developers to iterate with confidence and swiftly address any issues. Ultimately, automated tests promote code stability and facilitate smoother refactoring, enhancing the overall quality of the software.

The automated tests that are most suitable for code refactoring are automated unit tests. Unit tests should be written for each class and/or method. The IDE (integrated development environment) should then be configured to run the unit tests whenever changes are made to code.

Automated tests provide rapid feedback on whether the refactored code behaves as expected, enabling developers to iterate more quickly and confidently.

By automating the testing process, developers can quickly assess the impact of changes on the system’s functionality. This immediacy allows for rapid iteration, reducing the time between making a change and receiving feedback on its effects. Additionally, automated tests can be run frequently and consistently, catching issues early in the development cycle before they escalate into larger problems.

Automated tests provide rapid feedback on code changes, ensuring that any issues introduced during refactoring are identified immediately. This accelerates the development process by enabling quick iterations and reducing the time spent on debugging.

Automated tests ensure that the behavior of the refactored code remains consistent with the original functionality, reducing the risk of introducing new bugs.

Automated tests guarantee that the behavior of the code remains consistent throughout the refactoring process. By running the tests automatically, developers can be confident that the changes they make do not inadvertently alter the expected behavior of the code.

It is helpful to ensure that test input used for the automated tests include invalid partitions - inputs that will return an error. Invalid test inputs will ensure that code will respond consistently to negative scenarios, e.g calling the addFunds method with negative amount.

A slight pedantic quibble, but strictly "Refactoring" isn't risky at all, the problem is that without some verification, how can we tell that what we achieved was "Refactoring"? "Refactoring" by definition means a "Behaviour-Preserving change" so it can't, by definition, be risky, because after refactoring the code does all the same things, but in a different way. So the problem is not really that Refactoring is risky, but that not refactoring is risky, and in the absence of the protection that automated tests offer, we may inadvertently slip into not-refactoring, when we meant to refactor.

I would not want to work in a team or hire someone that didn't know you automate your tests as standard. There is a massive amount of literature on this practise. More advanced topics related to this are optimising your build with tests using stubs, in memory databases, etc. Other topics are automated generation of regression tests suites for complex applications and platforms using AI.

By verifying the correctness of the refactored code through automated tests, developers can mitigate the risk of introducing errors or breaking existing features.

Automated tests help to mitigate the risk associated with code refactoring by catching bugs early in the development cycle. By identifying issues before they reach production, automated tests minimize the impact of code changes and reduce the likelihood of introducing regressions.

Let's say to minimize risks, especially when making significant changes to important features, it's crucial to stay closely connected with both the development and QA teams. When we refactor the application code, it can impact our automated tests, which in turn affects the speed of feedback after changes. Therefore, fostering strong collaboration between teams is essential for effectively managing risks and ensuring success for all parties involved.

Automated tests serve as a form of documentation and provide a safety net for collaboration among team members. By ensuring that changes do not break existing functionality, automated tests enable developers to work together efficiently and with confidence.

Automated tests during code refactoring offer the benefit of efficient collaboration among team members. These tests provide a safety net by ensuring that the changes made during refactoring do not introduce new bugs or regressions. With automated tests in place, developers can refactor code with confidence, knowing that any potential issues will be caught early in the development process. This allows teams to work more collaboratively, as they can iterate quickly without the fear of breaking existing functionality.

Automated tests serve as a form of documentation for the intended behavior of the code, facilitating collaboration among team members by providing a clear understanding of the expected outcomes.

Incorporating automated tests into the refactoring process allows developers to continuously improve the codebase with confidence. By providing a safety net for making changes, automated tests facilitate the ongoing enhancement of the codebase while minimizing the risk of introducing new issues.

Incorporating automated tests into the refactoring process promotes a culture of continuous improvement by encouraging developers to write testable and maintainable code, leading to higher overall code quality.

Although automated tests are mostly extremely important in support of Refactoring, and usually to be strongly recommended, I don't think that they are essential under all circumstances. Modern tooling like the Refactoring IDEs from companies like JetBrains can safely make specific changes, specific "refactorings". If you use "Add Method" or "Extract Class" they will only proceed if they can do so safely. This can be useful on the route to changing code to make it more easily testable.

As a software engineer, I always try to write a test before refactoring because it speeds up my speed to refactor securely. These tests support me and ensure this refactoring does not pull down other parts of my code.

While automated tests accelerate refactoring efforts, does not mean that each refactoring that has automated coverage can be taken lightly. From a testing standpoint each and every work item deserves careful consideration and planning from a wholistic test perspective while utilizing automated tests as one of the various tools available in your toolset.

Automated tests ensure that existing functionalities remain intact after refactoring. They act as a safety net, catching any unintended changes that might occur during the process, thus preventing regressions.

This is a strange topic to be raised on LinkedIn. It's a bit like "Why do you think clean water is necessary to live?". It has been standard for quite some time that code testing is fully automated. Code scanning tools can check how much code is tested by unit tests, etc. and without a high level of automated testing Continuous Deployment is impossible. If your team isn't doing this I would recommend getting a different team! There are no excuses any more, there are so many ways to make continuous testing normal. We still need business level and security testing but this can and is integrated into automated testing processes.