c# - How to mock Session Object in asp net core

Question

I am writing unit tests using moq framework. I am calling one method in base controller setsession() which will set session using SetString("userdata",object) and I have one more method getsession() which will get session.

var sessionMock = new Mock<ISession>();
sessionMock.Setup(s => s.GetString("userdata")).Returns(Object);--failing
sessionMock.Setup(s => s.SetString("userdata",object));--failing

I am getting the error in s.GetString and s.SetString.

As GetString and SetString are extension methods may be I need to use another way to handle it.

Can you please help me?

Answer 1

According to ISession Extensions source code GetString and SetString are extension methods

public static void SetString(this ISession session, string key, string value)
{
    session.Set(key, Encoding.UTF8.GetBytes(value));
}

public static string GetString(this ISession session, string key)
{
    var data = session.Get(key);
    if (data == null)
    {
        return null;
    }
    return Encoding.UTF8.GetString(data);
}

public static byte[] Get(this ISession session, string key)
{
    byte[] value = null;
    session.TryGetValue(key, out value);
    return value;
}

You will need to mock ISession.Set and ISession.TryGetValue in order to let the extension methods execute as expected.

//Arrange
var sessionMock = new Mock<ISession>();
var key = "userdata";
var value = new byte[0];

sessionMock.Setup(_ => _.Set(key, It.IsAny<byte[]>()))
    .Callback<string, byte[]>((k,v) => value = v);

sessionMock.Setup(_ => _.TryGetValue(key, out value))
    .Returns(true);