package migrate import ( "errors" "fmt" "io/fs" "os" "path/filepath" "regexp" "runtime" "strings" ) type MigrationsOption func(m *Migrations) func WithMigrationsDirectory(directory string) MigrationsOption { return func(m *Migrations) { m.explicitDirectory = directory } } type Migrations struct { ms MigrationSlice explicitDirectory string implicitDirectory string } func NewMigrations(opts ...MigrationsOption) *Migrations { m := new(Migrations) for _, opt := range opts { opt(m) } m.implicitDirectory = filepath.Dir(migrationFile()) return m } func (m *Migrations) Sorted() MigrationSlice { migrations := make(MigrationSlice, len(m.ms)) copy(migrations, m.ms) sortAsc(migrations) return migrations } func (m *Migrations) MustRegister(up, down MigrationFunc) { if err := m.Register(up, down); err != nil { panic(err) } } func (m *Migrations) Register(up, down MigrationFunc) error { fpath := migrationFile() name, comment, err := extractMigrationName(fpath) if err != nil { return err } m.Add(Migration{ Name: name, Comment: comment, Up: up, Down: down, }) return nil } func (m *Migrations) Add(migration Migration) { if migration.Name == "" { panic("migration name is required") } m.ms = append(m.ms, migration) } func (m *Migrations) DiscoverCaller() error { dir := filepath.Dir(migrationFile()) return m.Discover(os.DirFS(dir)) } func (m *Migrations) Discover(fsys fs.FS) error { return fs.WalkDir(fsys, ".", func(path string, d fs.DirEntry, err error) error { if err != nil { return err } if d.IsDir() { return nil } if !strings.HasSuffix(path, ".up.sql") && !strings.HasSuffix(path, ".down.sql") { return nil } name, comment, err := extractMigrationName(path) if err != nil { return err } migration := m.getOrCreateMigration(name) if err != nil { return err } migration.Comment = comment migrationFunc := NewSQLMigrationFunc(fsys, path) if strings.HasSuffix(path, ".up.sql") { migration.Up = migrationFunc return nil } if strings.HasSuffix(path, ".down.sql") { migration.Down = migrationFunc return nil } return errors.New("migrate: not reached") }) } func (m *Migrations) getOrCreateMigration(name string) *Migration { for i := range m.ms { m := &m.ms[i] if m.Name == name { return m } } m.ms = append(m.ms, Migration{Name: name}) return &m.ms[len(m.ms)-1] } func (m *Migrations) getDirectory() string { if m.explicitDirectory != "" { return m.explicitDirectory } if m.implicitDirectory != "" { return m.implicitDirectory } return filepath.Dir(migrationFile()) } func migrationFile() string { const depth = 32 var pcs [depth]uintptr n := runtime.Callers(1, pcs[:]) frames := runtime.CallersFrames(pcs[:n]) for { f, ok := frames.Next() if !ok { break } if !strings.Contains(f.Function, "/bun/migrate.") { return f.File } } return "" } var fnameRE = regexp.MustCompile(`^(\d{1,14})_([0-9a-z_\-]+)\.`) func extractMigrationName(fpath string) (string, string, error) { fname := filepath.Base(fpath) matches := fnameRE.FindStringSubmatch(fname) if matches == nil { return "", "", fmt.Errorf("migrate: unsupported migration name format: %q", fname) } return matches[1], matches[2], nil }