Golang Unresolved type 'models'

I am new to golang and trying to understand why I am getting this error.

Unresolved type 'models'

I have struct declared called Users, as follow:

package models

import (
    "gorm.io/gorm"
    "time"
)

type Utenti struct {
    gorm.Model
    ID        int       `json:"id"`
    Name      string    `json:"name"`
    Surname   string    `json:"surname"`
    Email     string    `json:"email"`
    Username  string    `json:"username"`
    Password  []byte    `json:"-"`
}

when I try to use this model as a receiver in my auth process:

package authentication

import (
    "github.com/user/repo/internal/models"
    "golang.org/x/crypto/bcrypt"
)

// Encrypt the password before saving to the database
func (user *models.Utenti) HashPassword(password string) {
    hashedPassword, _ := bcrypt.GenerateFromPassword([]byte(password), 14)
    user.Password = hashedPassword
}

func (user *Utenti) ComparePassword(password string) bool {
    err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(password))
    return err == nil
}

the *models.Utenti show the error Unresolved type 'models'

I am using Goland and I tried to invalidate caches, I cleared golang caches. The issue happens only in this specific package (authentication), I can call the models and use it in all other places but this package.

As a work around, I also created the struct in the same package and passed the models.Utenti, as follow:

type Utenti struct {
    models.Utenti
}

and updated the above code to use *Utenti, this seems to have worked but in my actual code;

utenti := Utenti{
        Name:      data["name"].(string),
        Surname:   data["surname"].(string),
        Email:     strings.TrimSpace(data["email"].(string)),
        //....
    }

I am not able to access the Fields of the Struct.

At this point I am really confused and I am sure I missing some knowledge about using receivers from different packages etc.

If anyone can help me to understand this I will be grateful

How to reproduce:

Project Structure

├── cmd
│   └── server
│       └── main.go
├── db
│   └── db.go
├── db-init
├── go.mod
├── go.sum
└── internal
    ├── authentication
    │   ├── auth.go
    ├── models
    │   └── Utenti.go

in internal/models/Utenti.go

package models

import (
    "gorm.io/gorm"
    "time"
)

type Utenti struct {
    gorm.Model
    ID        int       `json:"id"`
    Name      string    `json:"name"`
    Surname   string    `json:"surname"`
    Email     string    `json:"email"`
    Username  string    `json:"username"`
    Password  []byte    `json:"-"`
}

In internal/authentication/auth.go

package authentication

import (
    "github.com/user/repo/internal/models"
    "golang.org/x/crypto/bcrypt"
)

// Encrypt the password before saving to the database
func (user *models.Utenti) HashPassword(password string) {
    hashedPassword, _ := bcrypt.GenerateFromPassword([]byte(password), 14)
    user.Password = hashedPassword
}

func (user *models.Utenti) ComparePassword(password string) bool {
    err := bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(password))
    return err == nil
}

With this you should see that the function HashPassword and ComparePassword, the (user *models.Utenti) is red and shows the mentioned error.

>Solution :

You have:

// Encrypt the password before saving to the database
func (user *models.Utenti) HashPassword(password string) {
    hashedPassword, _ := bcrypt.GenerateFromPassword([]byte(password), 14)
    user.Password = hashedPassword
}

But you can’t define a method on a type defined in another package. That’s why the weird error message: on the receiver func (user *models.Utenti), the thing after the receiver name must be a (not package-qualified) type.

It’s not clear what the "best" solution is, but perhaps you can just define a function:

// HashUtentiPassword updates the users password with a hashed version, to be used before saving to the database.
func HashUtentiPassword(user *models.Utenti, password string) {
    hashedPassword, _ := bcrypt.GenerateFromPassword([]byte(password), 14)
    user.Password = hashedPassword
}