.NET test coverage
SonarQube supports the reporting of test coverage information as part of the analysis of your .NET project.
However, SonarQube does not generate the coverage report itself. Instead, you must set up a third-party tool to produce the report as part of your build process. You then need to configure your analysis to tell the SonarScanner where the report is located so that it can pick it up and send it to SonarQube, where it will be displayed on your project dashboard along with the other analysis metrics.
SonarQube supports the following .NET test coverage tools:
- Visual Studio Code Coverage
- dotnet-coverage Code Coverage
- dotCover
- OpenCover
- Coverlet
Additionally, a generic coverage format is also supported if you wish to use an unsupported tool (though you will have to convert its output to the generic format yourself). In this section, we discuss the directly supported tools. For information on the generic format, see Generic test data.
Adding coverage to your build process
The .NET scanner comes in four variants depending on which version of .NET and which CI you are using (.NET Framework, .NET Core, .NET tool and SonarScanner for Azure DevOps). The setup is slightly different for each variant (see the SonarScanner for .NET and SonarQube Extension for Azure DevOps sections for details), but the essential steps are the same.
The analysis is always split into two parts in your build process; the begin step and the end step. In between, you perform the actual build and your tests. To enable coverage reporting, you need to make the following changes:
- In the scanner begin step, add the appropriate parameter to specify the location of the coverage report file that will be produced.
- Just after the build step but before the scanner end step, ensure that your test step produces the coverage report file.
Examples using the .NET tool scanner variant
The SonarScanner for .NET comes in four major variants: .NET Framework, .NET Core, .NET Global Tool, and the Azure Pipelines extension.
Visual Studio code coverage
We only recommend the use of this tool when the build agent has Visual Studio Enterprise installed or when you are using an Azure DevOps Windows image for your build. In these cases, the .NET Framework scanner will automatically find the coverage output generated by the --collect "Code Coverage"
parameter without the need for an explicit report path setting. It will also automatically convert the generated report to XML. No further configuration is required. Here is an example:
dotnet-coverage
This is a modern alternative to the Visual Studio Code Coverage provided by Microsoft (see above) that outputs results in the same format, is cross-platform, and not dependent on having Visual Studio installed. It requires .NET Core 3.1 or later.
To use dotnet-coverage, you can install it as a local or global dotnet tool:
Using this tool, your build script would look like something like this:
Note that we specify the path to the reports using sonar.cs.vscoveragexml.reportsPaths
because this tool’s output format is the same as the Visual Studio Code Coverage tool. We use the -f xml
parameter to specify that the output format is in XML.
dotCover
To use dotCover you must install it as a global dotnet tool:
Using this tool, your build script would look like something like this:
Note that we specify the path to the reports using sonar.cs.dotcover.reportsPaths
because we are using dotCover.
OpenCover
To use OpenCover you must download it from here and unzip it in an appropriate directory, for example: C:\tools\opencover
Using this tool, your build script would look like something like this:
Note that we specify the path to the reports using sonar.cs.opencover.reportsPaths
because we are using OpenCover.
Coverlet
To use Coverlet, you must install it as a global dotnet tool:
You also have to install the coverlet collector NuGet package on your test project.
Using this tool, your build script would look like something like this:
Note that we specify the path to the reports in sonar.cs.opencover.reportsPaths
because Coverlet produces output in the same format as OpenCover.
.NET Framework and .NET Core scanners
In most of the examples above, we use the .NET tool scanner variant. If you use the .NET Framework or .NET Core scanner, the commands will be a bit different but the pattern will be the same. See SonarScanner for .NET for details.
Extension for Azure Devops
Using the Extension for Azure DevOps and Visual Studio Code Coverage with a C# project, your azure-pipelines.yml
would look something like the example below.
Note that with the Extension for Azure DevOps extension, the scanner begin
step is handled by the SonarQubePrepare
task, and the scanner end
step is handled by the SonarQubeAnalyze
task.
Also note that because our build is running on Windows (we specify vmImage: windows-latest
), we do not need to explicitly specify the path to the coverage report (there is no sonar.cs.vscoveragexml.reportsPaths=coverage.xml
) nor do you need to run codecoverage.exe
to convert the report to XML.
VB.NET
The examples above are all for C# projects. For VB.NET projects the setup is identical except that you would use these parameters:
sonar.vbnet.vscoveragexml.reportsPaths
for Visual Studio Code Coveragesonar.vbnet.dotcover.reportsPaths
for dotCoversonar.vbnet.opencover.reportsPaths
for OpenCover or Coverlet
The parameter sonar.cs.ncover3.reportsPaths
was formerly used for NCover3. This parameter has been deprecated.
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