public async void IsOptionExsitedById_ShouldReturnBool() { // Arrange var expectedResult = new ProductOption() { Name = "option name" }; OptionRepositoryMock.Setup(x => x.IsOptionExistedById(expectedResult.Id)).ReturnsAsync(false); // Act var result = await ServiceTest.IsOptionExsitedById(expectedResult.Id); // Assert Assert.Equal(false, result); }