Function ensureTemplateDB

internal/database/testutil.go:21–55

ensureTemplateDB creates a template database with migrations applied Multiple processes may call this, so we handle race conditions

(ctx context.Context, adminConn *pgx.Conn)

// ensureTemplateDB creates a template database with migrations applied
// Multiple processes may call this, so we handle race conditions
func ensureTemplateDB(ctx context.Context, adminConn *pgx.Conn) error {
	// Check if template exists
	var exists bool
	err := adminConn.QueryRow(ctx, "SELECT EXISTS(SELECT 1 FROM pg_database WHERE datname = $1)", templateDBName).Scan(&exists)
	if err != nil {
		return fmt.Errorf("failed to check template database: %w", err)
	}

	if exists {
		// Template already exists
		return nil
	}

	// Create template database
	_, err = adminConn.Exec(ctx, fmt.Sprintf("CREATE DATABASE %s", templateDBName))
	if err != nil {
		// Ignore duplicate database name error - another process created it concurrently
		var pgErr *pgconn.PgError
		if errors.As(err, &pgErr) && pgErr.Code == "23505" && pgErr.ConstraintName == "pg_database_datname_index" {
			return nil
		}
		return fmt.Errorf("failed to create template database: %w", err)
	}

	// Connect to template and run migrations
	templateURI := fmt.Sprintf("postgres://mcpregistry:mcpregistry@localhost:5432/%s?sslmode=disable", templateDBName)
	templateDB, err := NewPostgreSQL(ctx, templateURI)
	if err != nil {
		return fmt.Errorf("failed to connect to template database: %w", err)
	}
	defer templateDB.Close()

	// Migrations run automatically in NewPostgreSQL
	return nil
}

// NewTestDB creates an isolated PostgreSQL database for each test by copying a template.
// The template database has migrations pre-applied, so each test is fast.