In this blog, we'll explore how to run with coverage in Visual Studio, what coverage metrics mean, and why they matter. Whether you're a beginner or an experienced developer, understanding and applying code coverage in your workflow can drastically improve software quality and reduce bugs in production.
What is Code Coverage?
Before diving into how to run with coverage in Visual Studio, let's clarify what code coverage means. Code coverage is a metric that shows the percentage of your code that is executed when running your tests. It helps answer a crucial question: "Are my tests actually testing the code?"
There are different types of code coverage, including:
- Statement coverage: Checks whether each line of code has been executed.
- Branch coverage: Ensures all possible paths (like if-else conditions) are tested.
- Function coverage: Verifies whether all functions or methods are called.
- Condition coverage: Checks if boolean expressions in conditions are evaluated to both true and false.
The higher your coverage, the more confidence you can have in your test suite. However, keep in mind that 100% coverage doesn't guarantee bug-free code—it just means your tests have touched all parts of the code.
Why Use Visual Studio for Code Coverage?
Visual Studio, especially the Enterprise edition, offers integrated code coverage analysis tools that are easy to use and visually informative. By running your unit tests with coverage enabled, Visual Studio generates a detailed report that shows covered, partially covered, and uncovered lines of code.
Here are a few reasons why developers prefer to run with coverage in Visual Studio:
- Seamless integration with test frameworks like MSTest, NUnit, and xUnit
- Intuitive UI with color-coded coverage results
- Easy navigation to untested code
- Useful for both managed (.NET) and unmanaged (C++) projects
- Works well with Azure DevOps and CI/CD pipelines
How to Run with Coverage in Visual Studio
Now let’s walk through the steps to run your unit tests with code coverage in Visual Studio:
Step 1: Open Your Solution
Open your project or solution in Visual Studio Enterprise. Make sure your solution includes a test project with properly configured test cases.
Step 2: Build Your Solution
Before running coverage, build your solution using Build > Build Solution or by pressing Ctrl+Shift+B. This ensures all test binaries are ready.
Step 3: Open Test Explorer
Go to Test > Test Explorer to view all your available tests. You’ll see the list of tests grouped by project or class.
Step 4: Run Tests with Coverage
Right-click on your test project or selected tests in the Test Explorer and click “Analyze Code Coverage for All Tests.” Visual Studio will now execute your tests and collect coverage data.
Step 5: View Coverage Results
Once the tests finish running, navigate to Test > Analyze Code Coverage > All Tests. A new Code Coverage Results window will appear. Here, you’ll see:
- The coverage percentage per assembly, class, and method
- A breakdown of covered and uncovered blocks
- An option to highlight code coverage in the editor, where covered lines appear in blue and uncovered lines in red
This helps you quickly identify weak spots in your test suite and take action.
Best Practices When Using Code Coverage
- Don’t chase 100% coverage blindly. Focus on testing business-critical logic and edge cases.
- Combine with other quality metrics like code complexity, cyclomatic complexity, and test pass rate.
- Use branch coverage over statement coverage for deeper validation.
- Regularly review coverage trends in your CI/CD pipeline with tools like Azure DevOps or GitHub Actions.
- Refactor uncovered code if it’s truly unreachable or obsolete.
Bonus: Use Extensions for Better Insights
If you're using the Community or Professional edition of Visual Studio, native code coverage tools may be limited. In that case, consider integrating third-party tools like:
- Coverlet – an open-source, cross-platform code coverage framework for .NET Core
- ReportGenerator – turns raw coverage reports into visually rich HTML reports
- OpenCover – works well with legacy .NET Framework applications
You can run these tools via command-line or integrate them into your CI/CD pipeline using scripts or GitHub Actions.
Final Thoughts
Learning how to run with coverage in Visual Studio is an essential step toward building more reliable and maintainable software. By understanding which parts of your code are tested and which are not, you can improve the effectiveness of your test suite, reduce regression bugs, and boost your team’s confidence in every release.
Whether you're developing enterprise-grade applications or personal side projects, taking advantage of Visual Studio's code coverage capabilities is a smart move for any developer aiming to ship high-quality code.
Read more on https://keploy.io/blog/community/how-to-run-tests-in-visual-studio-code-a-complete-guide