Companies that turn to code coverage often do so because of how difficult it is to keep track of code quality across a large codebase. For example, when multiple teams are working on separate software, like when developing different parts of an application, it can be difficult to see which parts have been tested by each team’s testing procedures.
In this article, you will learn about code coverage and the reasons why companies choose to adopt it. You’ll also see how Codecov can help you maintain yours.
What Is Code Coverage?
Code coverage is a measure of the percentage of source code that is tested by a test suite. There are different ways in which it can be calculated, but the most common method is to divide the number of statements executed by the total number of executable statements. A code coverage value of 100 percent indicates that all necessary tests for statements, functions, conditions, logic branches, etc. in a codebase have been executed at least once during testing.
Code coverage is important to ensure that your tests are checked against functional requirements and specifications. Without it, it is hard to know if your tests are comprehensive enough. It is also useful for determining what parts of your codebase need more tests. If you notice that certain parts of your codebase aren’t being tested, then you can focus your efforts on improving those areas first before moving on to other parts of the project.
How Should Code Coverage Be Maintained?
There are several things you can do to support maintaining high-quality software with code coverage. Here are a few strategies to consider.
Set a Goal
First, determine which part(s) of your project need to be tested and when and how you want to test them. Then set measurable goals, such as “increase our code coverage from 40% to 70%.” This gives your team a specific guideline to know what they need to focus on and how they can reach those goals.
It’s also important to make sure that all personnel are on board with the overall goal. Code coverage is something that should be measured across all areas of development (frontend, backend, etc.), so everyone should have a stake in improving these metrics.
Automate Whenever Possible
Automating code coverage is one of the most effective ways to ensure that your tests are covering all the code you want them to. It saves time and can help reveal gaps in your test suite that might otherwise be hard to spot.
To automate code coverage, you must create a test suite for your project and run unit, functional, and integration tests with each build. Then, incorporate your suite into a continuous integration (CI) tool with code coverage monitoring features, such as Codecov. You can then configure alerts to monitor your code coverage and detect when critical parts of the code are not being tested.
Analyze Your Results
Even if your code coverage score does not meet your goal, you can still use the results as a guide to refine your test suite. Whatever your score, it’ll be helpful in identifying which parts of your code need more attention and focus.
Code coverage tools like Codecov help you determine whether or not your tests are analyzing everything they need to by showing you exactly which lines of code are covered by automated tests and which are not, as well as an overall percentage score. You can see this information broken down per branch or commit so that you always have the full picture.
5 Reasons Companies Cover Their Code
As a company’s codebase expands, they should prioritize code coverage in order to maintain and enhance their overall software quality. In this section, you will explore five specific reasons it’s important that companies cover their code.
1. To Find Out How Much of Their Code Is Covered by Tests
As you’ve seen, the goal of code coverage is to make sure you have tests for all of the important parts of your application and that each part is well-tested. If you are writing code, it is easy to get carried away with building new features and forget about increasing coverage. Code coverage can help you identify those parts of your app where there are no tests.
2. To Identify Code Execution Paths Lacking Coverage
Code coverage can be used as an indicator of good testing practices and quality assurance. It can also help you identify areas of code that need additional testing. A high level of coverage does not necessarily mean that your application is bug-free, but it does indicate that most parts of your application have been tested at least once. Thus, if you’ve skipped covering some code, that code will be visible to you on your code coverage tool. Then, the appropriate tests can be written to evaluate them.
3. To Promote a Culture of Writing Unit Tests
Code coverage is useful in promoting a culture of writing unit tests. Unit testing is a critical part of writing code that is easily maintainable and scalable. For example, a company can set the following standards:
- All conditional statements must have an associated unit test case.
- Execution paths that contain one or more conditions, control structures, or functions must have an associated unit test case.
- Every test case should have at least 80 percent code coverage (or 90 percent, etc.).
With Codecov, companies can monitor and enforce these standards automatically to see where they need to focus effort in future test cycles.
4. To Instill Confidence in Their Developers to Make Changes
Code coverage grants you increased confidence that changes are unlikely to result in breakages as long as your tests are passing. This is especially important when you’re working on a large codebase, where making changes can be difficult and time-consuming. Having a high level of code coverage gives you more assurance that new features will not break existing features and also makes it easier to refactor code without worrying how their changes may negatively impact other parts of the codebase.
5. To Improve User Experience and Retention
Finally, code coverage can improve your user’s experience with your product. It can focus developer attention on the areas that need urgent improvement to decrease and prevent bug-related user frustration, thus increasing customer loyalty and improving retention.
Conclusion
Code coverage is a metric that shows you how much of your code is being tested. Your code coverage score and results enable you to know which parts of your code are sufficiently tested and which parts may require additional testing.
In this article, you learned that maintaining code coverage is a crucial part of the development process that can be achieved by setting a code coverage goal, writing extensive tests, and using code coverage tools to monitor and analyze your code coverage percentage.
You also reviewed several key reasons that companies cover their code. They do so to know which parts of their code are covered by tests, to identify code execution paths that need to be covered, to promote a culture of writing unit tests and complying with coverage rules, to instill confidence in their developers to make changes, and ultimately, to improve user experience and retention.
If you’re searching for a code coverage tool, be sure to check out Codecov—it’s a great solution for modern startups and enterprises alike that lets you track the code coverage of your builds in real-time. You can see exactly which lines are covered by tests and which ones aren’t—and why not—so you’ll know exactly what needs to be done to improve your testing coverage.
Codecov is integrated with the most popular tools and languages for development to make it easy for you to manage your project’s overall test suite. The app will tell you if any tests are failing or if any new bugs are being introduced into the codebase. This information helps you get back on track quickly whenever you run into problems with your software development process. Get started with Codecov today, or schedule a demo to learn more.
