Mutator

The Mutator tool provides methods to modify objects and create variants.

Example

A common scenario for this behavior is verifying a method’s behavior changes based upon input:

/// <summary>Verifies different hashes are generated for different values.</summary>
[Theory, RandomData]
public void GetHashCode_HashVaries(int original)
{
    int variant = Tools.Mutator.Variant(original);

    Tools.Asserter.ValuesNotEqual(
        ValueComparer.Use.GetHashCode(original),
        ValueComparer.Use.GetHashCode(variant));
}

Creation & Customization

The Mutator requires a Randomizer which controls the actual creation and randomization of object, a Valuer which verifies the created variant is unequal to the original by value, and a Limiter which limits the attempts at creating variants.

At the moment, Mutator completely relies upon other tools for its behavior. In the future as the behavior expands, it will work like other tools in that it can be customized by hints.