coverlet.msbuild 1.0.2

coverlet

Coverlet is a cross platform code coverage library for .NET Core, with support for line and method coverage.

Installation

Available on NuGet

Visual Studio:

PM> Install-Package coverlet.msbuild

.NET Core CLI:

dotnet add package coverlet.msbuild

How It Works

Coverlet integrates with the MSBuild system and that allows it to go through the following process:

Before Tests Run

• 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.

After Tests Run

• 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

Usage

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.

Code Coverage

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.

Coverage Output

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.

Excluding Classes/Methods From Coverage

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.

Roadmap

• Branch coverage
• Filter modules to be instrumented
• Support for more output formats (e.g. JaCoCo, Cobertura)
• Console runner (removes the need for requiring a NuGet package)

Issues & Contributions

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.

License

This project is licensed under the MIT license. See the LICENSE file for more info.