Constructor for dependency injection

constructor_injection.go

import "database/sql"

// Resource is type that being used as an object to receive dependency
type Resource struct {
	db *sql.DB
}

// New is constructor function that do the injection to Resource
func New(db *sql.DB) *Resource {
	r := &Resource{
		db: db,
	}

	return r
}

// PingDB is method receiver from type Resource which using database injection from constructor func
func (r *Resource) PingDB() error {
	return r.db.Ping()
}