Example of how to use AutoFixture with NSubstitute

Though the other answer has been marked as correct back then, I just wanted to add for completeness that you can indeed use AutoNSubstituteCustomization:

var fixture = new Fixture().Customize(new AutoNSubstituteCustomization() { ConfigureMembers = true});  
var result = fixture.Create<IPersonEntity>();

This will result in the properties being populated.

Instead of customizing the Fixture instance with the AutoNSubstituteCustomization you may use the customization below:

var fixture = new Fixture().Customize(
    new AutoPopulatedNSubstitutePropertiesCustomization());

var result = fixture.Create<IPersonEntity>();
// -> All properties should be populated now.

The AutoPopulatedNSubstitutePropertiesCustomization is defined as:

internal class AutoPopulatedNSubstitutePropertiesCustomization
    : ICustomization
{
    public void Customize(IFixture fixture)
    {
        fixture.ResidueCollectors.Add(
            new Postprocessor(
                new NSubstituteBuilder(
                    new MethodInvoker(
                        new NSubstituteMethodQuery())),
                new AutoPropertiesCommand(
                    new PropertiesOnlySpecification())));
    }

    private class PropertiesOnlySpecification : IRequestSpecification
    {
        public bool IsSatisfiedBy(object request)
        {
            return request is PropertyInfo;
        }
    }
}

The difference with the AutoNSubstituteCustomization is that the above customization is also decorated with a Postprocessor instance to automatically set values for all the public properties of the requested type.

References:

The above solution is inspired by the following blog articles by Mark Seemann:

• How to configure AutoMoq to set up all properties
• How to automatically populate properties with AutoMoq