Agilent.Testables.MessageBox

This package contains an abstraction of the static System.Windows.MessageBox class found in .NET Framework 4.8 and .NET 8.0. It allows for an IMessageBox interface to be used instead and for mocks to be created.

Usage

1. Pass IMessageBox as a dependency via the constructor into the class you want to show a MessageBox from:

public class TestableClass
{
    private readonly IMessageBox _messageBox;

    public TestableClass(IMessageBox messageBox)
    {
        _messageBox = messageBox;
    }

    public void DoWork()
    {
        _messageBox.Show("Hello World");
    }
}

2. In your IOC Container register IMessageBox and Agilent.Testables.MessageBox:

_services.AddTransient<IMessageBox, MessageBox>();

3. In your tests, verify that the correct message is shown:

[TestMethod]
public void Should_ShowMessageBox_When_DoWorkPerformed()
{
    // Arrange
    var mockMessageBox = new Mock<IMessageBox>();
    var sut = new TestableClass(mockMessageBox.Object);

    // Act
    sut.DoWork();

    // Assert
    mockMessageBox.Verify(x => x.Show(It.IsAny<string>()), Times.Once);
}