mutannot/skills/write-mutations/SKILL.md

name	description
Write mutations	Trigger when asked to write mutations

Annotate tests with one or more mutations (MutationCases) that will cause the test to fail.

Example:

[<Fact>]
[<MutationCase("calc-operator-mixup", "Calculator/Calculator.fs", 4, "value + 1", "value - 1")>]
member _.AddOne_increments() =
    Assert.Equal(42, Calculator.addOne 41)

In this example,

• calc-operator-mixup is the mutation name,
• Calculator/Calculator.fs is the path to the production code (relative to the repository root),
• 4 is the number of the line to mutate,
• value + 1 is the string to find, and
• value - 1 is the string to replace it with.

Verify your work with mutannot <path/to/test-project.fsproj> --run <mutation id 1> <mutation id 2> <...>.