Dispose Pattern (ARCH5082)

Key go.performance.dispose-pattern · Severity warning · Category performance

A struct holding a closeable field that exposes no Close method of its own means its owned resources never get released. Surface the ownership chain with a Close.

Incorrect

type Repo struct {
  db *sql.DB
}

func NewRepo(dsn string) (*Repo, error) {
  db, err := sql.Open("postgres", dsn)
  return &Repo{db: db}, err
}

Correct

type Repo struct {
  db *sql.DB
}

func NewRepo(dsn string) (*Repo, error) {
  db, err := sql.Open("postgres", dsn)
  return &Repo{db: db}, err
}

func (r *Repo) Close() error {
  return r.db.Close()
}

Fix

Add a Close method to the struct that releases its closeable fields.