That way, you can create a token with an expiration of, let's say, 1 week. And then when the user comes back the next day with the token, you know that user is still logged in to your system.

		return nil, err
	}

	m.Range(func(user string, mappedPolicy MappedPolicy) bool {
		if userPredicate != nil && !userPredicate(user) {
			return true
		}
		stsMap[user] = mappedPolicy.Policies
		return true
	})

	for user := range store.getParentUsers(cache) {
		if _, ok := stsMap[user]; !ok {
			if userPredicate != nil && !userPredicate(user) {
				continue
			}
			stsMap[user] = ""

	if user6.Name != "find or init" || user6.ID == 0 || user6.Age != 44 {
		t.Errorf("user should be found and updated with assigned attrs")
	}
}

func TestFindOrCreate(t *testing.T) {
	var user1, user2, user3, user4, user5, user6, user7, user8 User
	if err := DB.Where(&User{Name: "find or create", Age: 33}).FirstOrCreate(&user1).Error; err != nil {
		t.Errorf("no error should happen when FirstOrInit, but got %v", err)
	}

	userIdentities := make([]UserIdentity, len(users))
	g := errgroup.WithNErrs(len(users))

	for index := range users {
		g.Go(func() error {
			userName := path.Dir(users[index])
			user, err := iamOS.loadUserIdentity(ctx, userName, userType)
			if err != nil && !errors.Is(err, errNoSuchUser) {
				return fmt.Errorf("unable to load the user `%s`: %w", userName, err)

Esto será especialmente útil cuando lo uses en una **gran base de código** donde uses **las mismas dependencias** una y otra vez en **muchas *path operations***.

## Usar `async` o no usar `async`

func TestMany2ManyAssociation(t *testing.T) {
	user := *GetUser("many2many", Config{Languages: 2})

	if err := DB.Create(&user).Error; err != nil {
		t.Fatalf("errors happened when create: %v", err)
	}

	CheckUser(t, user, user)

	// Find
	var user2 User
	DB.Find(&user2, "id = ?", user.ID)
	DB.Model(&user2).Association("Languages").Find(&user2.Languages)

	CheckUser(t, user2, user)

	// Count

But in this case, the same **FastAPI** application will handle the API and the authentication.

So, let's review it from that simplified point of view:

* The user types the `username` and `password` in the frontend, and hits `Enter`.

)

func TestDistinct(t *testing.T) {
	users := []User{
		*GetUser("distinct", Config{}),
		*GetUser("distinct", Config{}),
		*GetUser("distinct", Config{}),
		*GetUser("distinct-2", Config{}),
		*GetUser("distinct-3", Config{}),
	}
	users[0].Age = 20

	if err := DB.Create(&users).Error; err != nil {
		t.Fatalf("errors happened when create users: %v", err)
	}

	var names []string

	}

	DB.Table("users").Select("id, name, age").Where("id = ?", user2.ID).Scan(&res)
	if res.ID != user2.ID || res.Name != user2.Name || res.Age != int(user2.Age) {
		t.Fatalf("Scan into struct should work, got %#v, should %#v", res, user2)
	}

	DB.Model(&User{Model: gorm.Model{ID: user3.ID}}).Select("id, name, age").Scan(&res)
	if res.ID != user3.ID || res.Name != user3.Name || res.Age != int(user3.Age) {

							},
						},
					},
				},
			},
			"SELECT * FROM `users` INNER JOIN `articles` ON `articles`.`id` = `users`.`id`", nil,
		},
		{
			[]clause.Interface{
				clause.Select{}, clause.From{
					Tables: []clause.Table{{Name: "users"}},
					Joins: []clause.Join{
						{
							Type:  clause.RightJoin,
							Table: clause.Table{Name: "profiles"},