c# - How to Mock SystemClock.Instance.GetCurrentInstant()?

Question

Good Morning everyone.

I'm new to all the Mocking stuff and I want to test a method that calls SystemClock.Instance.GetCurrentInstant() to retrieve it as a LocalDateTime. I have a second method to cast it to string. This are both methods:

    /// <summary>
    /// Transforms the current instant in the user's data time zone to string following the GeneralIso format.
    /// </summary>
    /// <returns>
    /// A string with the current instant in the user's data time zone
    /// </returns>
    public static string GetCurrentLocalTimeInGeneralIsoFormat()
    {
        return LocalDateTimePattern.GeneralIso.Format(GetCurrentLocalTime());
    }

    /// <summary>
    /// Retrieves the current instant in the user's data time zone.
    /// </summary>
    /// <returns>
    /// A LocalDataTime with the current instant in the user's data time zone
    /// </returns>
    public static LocalDateTime GetCurrentLocalTime()
    {
        return SystemClock.Instance.GetCurrentInstant().InZone(DateTimeZoneProviders.Bcl.GetSystemDefault()).LocalDateTime;
    }

I tried the following TestMethod using a Mock:

[TestMethod]
    public void TestGetCurrentLocalTimeInGeneralIsoFormat()
    {
        // Arrange
        string expectedAnswer = "2020-02-03 12:32";
        Mock<DateUtils> localTimeMock = new Mock<DateUtils>();
        localTimeMock.Setup(x => DateUtils.GetCurrentLocalTimeInGeneralIsoFormat()).Returns(expectedAnswer).Verifiable();
        // Act
        string currentLocalDateTime = DateUtils.GetCurrentLocalTimeInGeneralIsoFormat();

        // Assert
        Assert.IsInstanceOfType(currentLocalDateTime, typeof(string));
        Assert.AreEqual(currentLocalDateTime, expectedAnswer);
    }

But I just recieve the following error:

Message: 
Test method TachoShareAgent.Tests.DateUtilsTests.TestGetCurrentLocalTimeInGeneralIsoFormat threw exception: 
System.NotSupportedException: Invalid setup on a static member: x => DateUtils.GetCurrentLocalTimeInGeneralIsoFormat()

I tried several approaches as implementing an interface and not using a static method, but again i'm new to all this kind of stuff and I'm a bit lost.

Thanks in advance.

Edit:

I'm aware of this solution (Mock static property with moq) but I would like to know if there are any other options apart of making a virtual element.

c# - How to Mock SystemClock.Instance.GetCurrentInstant()?

0 Answers0