public void EvaluateReturnsResultOfFileCheck() { var fileSystemMock = new Mock <IFileSystem>(MockBehavior.Strict); fileSystemMock.Setup(fs => fs.CheckIfFileExists("c:\\test.xml")).Returns(true); var condition = new FileExists { FileName = "c:\\test.xml", FileSystem = fileSystemMock.Object }; var contextMock = new Mock <TaskExecutionContext>(new TaskExecutionParameters()); var result = condition.Evaluate(contextMock.Object); Assert.IsTrue(result); }