RamSQL

Disposable SQL engine

RamSQL has been written to be used in your project's test suite.

Unit testing in Go is simple:

create a foo_test.go
add import testing
add func Test...(t *testing.T) {...}
run go test ./...

But then there are SQL queries, constraints, CRUD... and suddenly you need a PostgresSQL, setup scripts, and nothing is easy anymore.

The idea is to avoid setup, DBMS installation, and credentials management as long as possible. A unique engine is tied to a single sql.DB with as much sql.Conn as needed providing a unique DataSourceName. Bottom line: One DataSourceName per test and you have full test isolation in no time.

Installation

go get github.com/mlhoyt/ramsql

Usage

Let's say you want to test the function LoadUserAddresses:

func LoadUserAddresses(db *sql.DB, userID int64) ([]string, error) {
  query := `SELECT
      address.street_number,
      address.street
    FROM address 
    JOIN user_addresses
    ON address.id = user_addresses.address_id 
    WHERE user_addresses.user_id = $1;`

  rows, err := db.Query(query, userID)
  if err != nil {
    return nil, err
  }

  var addresses []string
  for rows.Next() {
    var number int
    var street string
    if err := rows.Scan(&number, &street); err != nil {
      return nil, err
    }
    addresses = append(addresses, fmt.Sprintf("%d %s", number, street))
  }

  return addresses, nil
}

Use RamSQL to test it in a disposable isolated in-memory SQL engine:

package myproject 

import (
  "database/sql"
  "fmt"
  "testing"

  _ "github.com/mlhoyt/ramsql/driver"
)


func TestLoadUserAddresses(t *testing.T) {
  batch := []string{
    `CREATE TABLE address (id BIGSERIAL PRIMARY KEY, street TEXT, street_number INT);`,
    `CREATE TABLE user_addresses (address_id INT, user_id INT);`,
    `INSERT INTO address (street, street_number) VALUES ('rue Victor Hugo', 32);`,
    `INSERT INTO address (street, street_number) VALUES ('boulevard de la République', 23);`,
    `INSERT INTO address (street, street_number) VALUES ('rue Charles Martel', 5);`,
    `INSERT INTO address (street, street_number) VALUES ('chemin du bout du monde ', 323);`,
    `INSERT INTO address (street, street_number) VALUES ('boulevard de la liberté', 2);`,
    `INSERT INTO address (street, street_number) VALUES ('avenue des champs', 12);`,
    `INSERT INTO user_addresses (address_id, user_id) VALUES (2, 1);`,
    `INSERT INTO user_addresses (address_id, user_id) VALUES (4, 1);`,
    `INSERT INTO user_addresses (address_id, user_id) VALUES (2, 2);`,
    `INSERT INTO user_addresses (address_id, user_id) VALUES (2, 3);`,
    `INSERT INTO user_addresses (address_id, user_id) VALUES (4, 4);`,
    `INSERT INTO user_addresses (address_id, user_id) VALUES (4, 5);`,
  }

  db, err := sql.Open("ramsql", "TestLoadUserAddresses")
  if err != nil {
    t.Fatalf("sql.Open : Error : %s\n", err)
  }
  defer db.Close()

  for _, b := range batch {
    _, err = db.Exec(b)
    if err != nil {
      t.Fatalf("sql.Exec: Error: %s\n", err)
    }
  }

  addresses, err := LoadUserAddresses(db, 1)
  if err != nil {
    t.Fatalf("Too bad! unexpected error: %s", err)
  }

  if len(addresses) != 2 {
    t.Fatalf("Expected 2 addresses, got %d", len(addresses))
  }

}

Done. No need for a running PostgreSQL or a setup. Your tests are isolated, and compliant with go tools.

RamSQL binary

Let's say you have a SQL describing your application structure:

CREATE TABLE IF NOT EXISTS address (id BIGSERIAL PRIMARY KEY, street TEXT, street_number INT);
CREATE TABLE IF NOT EXISTS user_addresses (address_id INT, user_id INT);

You may want to test its validity:

$ go install github.com/mlhoyt/ramsql
$ ramsql < schema.sql
ramsql> Query OK. 1 rows affected
ramsql> Query OK. 1 rows affected
$ echo $?
0

Features

Unit testing

Full isolation between tests
No setup (either file or databases)
Good performance

SQL parsing

Databse schema validation
ALTER file validation

Stress testing

File system full error with configurable maximum database size
Random configurable slow queries
Random deconnection

parrasajad / ramsql