What's the best way to delete all database records used for a Test suite? - sql

Question

I have a test suite that pollute my database using a seed read from a YAML file.
I'm wondering is there a way to clean my database (delete all records used for the test suite) after running my tests.
// Open db and returns pointer and closer func
func prepareMySQLDB(t *testing.T) (db *sql.DB, closer func() error) {
db, err := sql.Open("mysql", "user:pass#/database")
if err != nil {
t.Fatalf("open mysql connection: %s", err)
}
return db, db.Close
}
// Pollute my database
func polluteDb(db *sql.DB, t *testing.T) {
seed, err := os.Open("seed.yml")
if err != nil {
t.Fatalf("failed to open seed file: %s", err)
}
defer seed.Close()
p := polluter.New(polluter.MySQLEngine(db))
if err := p.Pollute(seed); err != nil {
t.Fatalf("failed to pollute: %s", err)
}
}
func TestAllUsers(t *testing.T) {
t.Parallel()
db, closeDb := prepareMySQLDB(t)
defer closeDb()
polluteDb(db, t)
users, err := AllUsersD(db)
if err != nil {
t.Fatal("AllUsers() failed")
}
got := users[0].Email
if got != "myemail#gmail.com" {
t.Errorf("AllUsers().Email = %s; want myemail#gmail.com", got)
}
got1 := len(users)
if got1 != 1 {
t.Errorf("len(AllUsers()) = %d; want 1", got1)
}
}
// Test I'm interested in
func TestAddUser(t *testing.T) {
t.Parallel()
db, closeDb := prepareMySQLDB(t)
defer closeDb()
polluteDb(db, t)
user, err := AddUser(...)
if err != nil {
t.Fatal("AddUser() failed")
}
//how can I clean my database after this?
}
Should I retrieve the last ID inserted in TestAddUser() and just delete that line manually or there's any other way to save my database state and retrieve it after?
As I said I'm new to Go so any other comments on my code or what so ever are strongly appreciated.

Answer 1

The best way is usually to use a transaction, then ROLLBACK, so they are never committed in the first place.
The github.com/DATA-DOG/go-txdb package can help a lot with that.
Final code:
import (
"database/sql"
"os"
"testing"
txdb "github.com/DATA-DOG/go-txdb"
"github.com/romanyx/polluter"
)
//mostly sql tests
func init() {
txdb.Register("txdb", "mysql", "root:root#/betell_rest")
}
func TestAddUser(t *testing.T) {
db, err := sql.Open("txdb", "root:root#/betell_rest")
if err != nil {
t.Fatal(err)
}
defer db.Close()
users, _ := AllUsers(db)
userscount := len(users)
err = AddUser(db, "bla#gmail.com", "pass")
if err != nil {
t.Fatal("AddUser() failed")
}
users, _ = AllUsers(db)
if (userscount + 1) != len(users) {
t.Fatal("AddUser() failed to write in database")
}
}
Note: Also you can pass db into your polluter so you don't affect your database at all.