public async Task Update_NoSuchId_ReturnNotFound(IdentityRole role, CreateRoleDto dto, [Frozen] Mock <RoleManager <IdentityRole> > roleManagerMock, [Frozen] Mock <IMapper> mapper) { //Arrange roleManagerMock.Setup(c => c.FindByIdAsync(It.IsAny <string>())) .ReturnsAsync((IdentityRole)null); mapper.Setup(m => m.Map <CreateRoleDto, IdentityRole>(It.IsAny <CreateRoleDto>())).Returns(role); var sut = new RolesController(roleManagerMock.Object, mapper.Object); //Act var result = await sut.PutAsync(It.IsAny <string>(), dto); //Assign Assert.NotNull(result); Assert.IsType <NotFoundResult>(result); }