package sqlmock import ( "database/sql" "database/sql/driver" "fmt" "sync" ) var pool *mockDriver func init() { pool = &mockDriver{ conns: make(map[string]*sqlmock), } sql.Register("sqlmock", pool) } type mockDriver struct { sync.Mutex counter int conns map[string]*sqlmock } func (d *mockDriver) Open(dsn string) (driver.Conn, error) { d.Lock() defer d.Unlock() c, ok := d.conns[dsn] if !ok { return c, fmt.Errorf("expected a connection to be available, but it is not") } c.opened++ return c, nil } // New creates sqlmock database connection // and a mock to manage expectations. // Pings db so that all expectations could be // asserted. func New() (*sql.DB, Sqlmock, error) { pool.Lock() dsn := fmt.Sprintf("sqlmock_db_%d", pool.counter) pool.counter++ smock := &sqlmock{dsn: dsn, drv: pool, ordered: true} pool.conns[dsn] = smock pool.Unlock() return smock.open() } // NewWithDSN creates sqlmock database connection // with a specific DSN and a mock to manage expectations. // Pings db so that all expectations could be asserted. // // This method is introduced because of sql abstraction // libraries, which do not provide a way to initialize // with sql.DB instance. For example GORM library. // // Note, it will error if attempted to create with an // already used dsn // // It is not recommended to use this method, unless you // really need it and there is no other way around. func NewWithDSN(dsn string) (*sql.DB, Sqlmock, error) { pool.Lock() if _, ok := pool.conns[dsn]; ok { pool.Unlock() return nil, nil, fmt.Errorf("cannot create a new mock database with the same dsn: %s", dsn) } smock := &sqlmock{dsn: dsn, drv: pool, ordered: true} pool.conns[dsn] = smock pool.Unlock() return smock.open() }