Migrating a TS file

Goal: Apply the TS→SJS rewrite checklist on a real module.

1. Rename .ts → .sjs.
2. Fix banned constructs (any→dynamic, enum→sum types).
3. Run superjs migrate from-prototype if imports still point at prototype paths.
4. Run superjs check until clean.

Full guide: Migration.

Example

// After migration — no any, no enum
type Role = Admin | Member

type User {
  name: string;
  role: Role;
}

function roleLabel(u: User): string {
  return match u.role {
    Admin => "admin",
    Member => "member",
  }
}

Open in playground

Key takeaways

• Migrate leaf modules first.
• Use the compat matrix for npm wrappers.
• superjs migrate from-ts assists bulk moves.