Testura.Mutation

Testura is visual studio extension for C# that verifies the quality of your unit tests by injecting different mutations in your production code and then checks whether your unit tests catch them. If your unit tests:

• Fail it means that your tests found the mutation and you have good coverage.
• Pass it means that the mutant survived and you do not have sufficient coverage of the specific functionality.

Usage

Configuration

The first thing you need to do is to configure the extension at Extensions > Testura.Mutation > Config...

Here you will pick test runner, your test projects and mutations to run.

Note: We recommend that you try with the DotNet test runner first as it should work in most cases with all frameworks.

Create mutations

You can run mutations in three different ways:

• Go to Extensions > Testura.Mutation > Mutate solution.. to mutate the whole solution (except for ignored/test projects).
• Right-click on solution, project, directory or files in the solution explorer and pick Mutate files...
• Go to a file, select lines that you want to mutate and then right-lick and pick Mutate lines

It may take a while to create your mutations depending on number of files/lines.

When they are done you see how the mutation look by clicking the small blue button the the right or double click and hover over the statement (if you have highlight on).

Run mutations

Click the play icon in the mutation explorer to run your mutations. The mutations will either:

• Survive (red icon) which means that you don't have unit test that cover this mutation.
• Die (green icon) which means that your unit test found the mutation.
• Finish with unknown error (purple icon), this are usually because of compilation errors (bad mutation).

Highlights

It's possible to see the status of your mutations in code.