How to mock private variable that in a static class

[Dino]

There is a private variable that in a static class:

public static class Common     {   

        private static EMailSetting _mailSetting;

......

        public void BeTest()

        {

                if(_mailSetting=null){

                   //do something

               }

               ........

        }

}

How can I  mock "_mailSetting"?

I try this code, It's not work:

Mock.SetupStatic(typeof(Common), Behavior.CallOriginal, StaticConstructor.Mocked);             

Mock.NonPublic.Arrange<EMailSetting>(typeof(Common), "_mailSetting")                 

    .Returns(() =>                 {                    

            var mockMailSetting = Mock.Create<EMailSetting>();                     

            mockMailSetting.mailFrom = "C";                     

            mockMailSetting.mailTo = "D";                

            return mockMailSetting;                 

});

Common.BeTest();

[Svetlozar]

Hello,

Thank you for the great question.

You can not mock fields directly with JustMock. We intercept method implementations, but fields don't have such. On the other hand you can mock properties and events, because internally they have get/set and add/remove methods.  

For the example you've provided I suggest you change the _mailSetting field to be a private property. Here is the complete sample in a console app.

class Program
{
    static void Main(string[] args)
    {
        Mock.NonPublic.Arrange<EMailSetting>(typeof(Common), "_mailSetting")
            .Returns(() => {
                var mockMailSetting = Mock.Create<EMailSetting>();
                mockMailSetting.mailFrom = "C";
                mockMailSetting.mailTo = "D";
                return mockMailSetting;
            });
        Common.BeTest();
    }
}

internal class EMailSetting
{
    public string mailFrom { get; set; }
    public string mailTo { get; set; }
}

public static class Common
{
    private static EMailSetting _mailSetting { get; set; }

    public static void BeTest()
    {
        if (_mailSetting != null)
        {
            Console.WriteLine(_mailSetting.mailFrom);
        }
    }
}

Let me know if you have any questions.

Regards,
Svetlozar
Telerik by Progress

[Dino]

Thank you very much.