InMemoryDB example.go

package main

import (
	"log"
	"errors"
)

func main() {
	// Create new MemoryDB 
	database := NewMemDB()
	// Add User
	err := database.AddUser("findMe", "[email protected]")
	if err != nil {
		log.Fatal(err)
	}
	user, err := database.GetUser("findMe")
	if err != nil {
		log.Fatal(err)
	}
	
	log.Println(user)
}
// User is a data representation of our users
type User struct {
	Name string
	Email string
}
// MemoryDatabase is a user database that holds users in memory
type MemoryDatabase struct {
	Users map[string]*User
}

func NewMemDB() MemoryDatabase{
	return MemoryDatabase{
		Users: make(map[string]*User),
	}
}
// GetUser will print a user or an Error if not found
func (memDB *MemoryDatabase) GetUser(username string) (*User, error){
	// Search for User
	if user, ok := memDB.Users[username]; ok {
		return user, nil
	}
	return nil, errors.New("User does not exist")
}
// AddUser will add a user to the database
func (memDB *MemoryDatabase) AddUser(username, email string) error {
	if _, ok := memDB.Users[username]; ok {
    		return errors.New("User already exists")
	}
	memDB.Users[username] = &User{
		Name: username,
		Email: email,
	}
	return nil
}