public void DeleteAsync_IdRecognised_ReturnsTrue() { var firstEntity = new Employee { Id = 1, }; var data = new List <Employee> { firstEntity }; var mockSet = data.AsQueryable().BuildMockDbSet(); var mockDbContext = Substitute.For <IDatabaseContext>(); mockDbContext.Set <Employee>().Returns(mockSet); var mockLogger = Substitute.For <ILogger <EmployeeDal> >(); var dal = new EmployeeDal(mockDbContext, mockLogger); var result = Task.Run(async() => await dal.DeleteAsync(1)).GetAwaiter().GetResult(); Assert.That(result, Is.True); }