Coverlet is a cross platform code coverage library for .NET Core, with support for line and method coverage.
Available on NuGet
Visual Studio:
PM> Install-Package coverlet.msbuild
.NET Core CLI:
dotnet add package coverlet.msbuild
Coverlet integrates with the MSBuild system and that allows it to go through the following process:
- Locate the unit test assembly and selects all the referenced assemblies that have PDBs.
- Instruments the selected assemblies by inserting code to record sequence point hits to a temporary file.
- Restore the original non-instrumented assembly files.
- Read the recorded hits information from the temporary file.
- Generate the coverage result from the hits information and write it to a file.
Note: The assembly you'd like to get coverage for must be different from the assembly that contains the tests
Coverlet doesn't require any additional setup other than including the NuGet package. It integrates with the dotnet test
infrastructure built into the .NET Core CLI and when enabled will automatically generate coverage results after tests are run.
Enabling code coverage is as simple as setting the CollectCoverage
property to true
dotnet test /p:CollectCoverage=true
After the above command is run, a coverage.json
file containing the results will be generated in the root directory of the test project. A summary of the results will also be displayed in the terminal.
Coverlet can generate coverage results in multiple formats, which is specified using the CoverletOutputFormat
property. Possible values include json
(default), lcov
and opencover
. For example, the following command emits coverage results in the opencover format:
dotnet test /p:CollectCoverage=true /p:CoverletOutputFormat=opencover
The output folder of the coverage result file can also be specified using the CoverletOutputDirectory
property.
By default, Coverlet instruments every method of every class but sometimes for any number of reasons you might want it to ignore a specific method or class altogether. This is easily achieved by creating and applying the ExcludeFromCoverage
attribute to the method or the class. Coverlet uses just the type name so the ExcludeFromCoverage
class can be created under any namespace you wish. Also, in line with standard C# convention, either ExcludeFromCoverage
or ExcludeFromCoverageAttribute
will work.
- Branch coverage
- Filter modules to be instrumented
- Console runner (removes the need for requiring a NuGet package)
If you find a bug or have a feature request, please report them at this repository's issues section. Contributions are highly welcome, however, except for very small changes, kindly file an issue and let's have a discussion before you open a pull request.
This project is licensed under the MIT license. See the LICENSE file for more info.