PosInfoMoq2007.md

PosInfoMoq2007: The As<T>() method can be used only with interfaces.

Property	Value
Rule ID	PosInfoMoq2007
Title	The As<T>() method can be used only with interfaces.
Category	Compilation
Default severity	Error

Cause

The As<T>() method is used with a type which is not an interface.

Rule description

Moq allows to add additional implementations for mocked class (or interface) by adding additional interfaces with the As<T>() method.

[Fact]
public void Test()
{
    var service = new Mock<Service>();
    service.As<IDisposable>()           // Add IDisposable implementation for the mocked Service class.
        .Setup(s => s.Dispose());
    service.As<OtherService>();         // An error will be raised, because we can't mock additional implementation of a class.
}

public abstract class Service
{
}

public abstract class OtherService
{
}

How to fix violations

To fix a violation of this rule, use an interface when using the As<T>() method.

When to suppress warnings

Do not suppress an error from this rule. If bypassed, the execution of the unit test will be failed with a MoqException thrown with the "Can only add interfaces to the mock." message.