Gorm add additional methods to gorm.DB?

Your Question

is there a way to add additional methods to gorm.DB? i want to make some wrappers for existing gorm.DB methods and the usual way of defining a new type seems to panic.

The document you expected this should be explained

the main docs, most likely.

Expected answer

something like this:

type DB struct {
    gorm.DB
}

func GetDatabase() (*DB, err) {
    db, err := gorm.Open(/* ... */)
    return &DB{*db}
}

func (db *DB) Migrate() {
    db.AutoMigrate(&User{})
}

func main() {
    db, _ := GetDatabase()
    db.Migrate()
}

alas, when i run it, it panics:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x28 pc=0x888798]

goroutine 1 [running]:
gorm.io/gorm.(*DB).getInstance(0x40f46a?)
    /home/sfr/.local/share/go/pkg/mod/gorm.io/gorm@v1.25.1/gorm.go:390 +0x18
gorm.io/gorm.(*DB).Migrator(0x40f847?)
    /home/sfr/.local/share/go/pkg/mod/gorm.io/gorm@v1.25.1/migrator.go:12 +0x19
gorm.io/gorm.(*DB).AutoMigrate(0xc000207880?, {0xc0002d4250, 0x1, 0x1})
    /home/sfr/.local/share/go/pkg/mod/gorm.io/gorm@v1.25.1/migrator.go:24 +0x28
git.sr.ht/~sfr/celatum/database.(*DB).Migrate(...)
    /home/sfr/src/celatum/database/database.go:44
main.main()
    /home/sfr/src/celatum/main.go:35 +0x1e5
exit status 2

Comment From: black-06

It works:

type DB struct {
    *gorm.DB
}

func GetDatabase() *DB {
    db, _ := gorm.Open(/* ... */)
    return &DB{DB: db}
}

func (db *DB) Migrate() {
    type User struct {
        ID   int
        Name string
    }
    db.Debug().AutoMigrate(&User{})
}

func TestMyDB(t *testing.T) {
    database := GetDatabase()
    database.Migrate()
}

Maybe you should create a playground pr