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Launch announcement drafts

Do not publish until superjs@1.0.0 GA. Edit URLs and version numbers before posting.

Show HN (draft)

Title: Show HN: SuperJS – a sound superset of JS with sum types (not TypeScript++

Body:

We built SuperJS (SJS) — a strict superset of JavaScript with a hand-written compiler (no Babel/tsc at runtime). It's designed for teams who want null safety and algebraic types without TypeScript's unsound escape hatches (any, intersections, conditional types).

What's in 1.0:

  • Sound null safety, sum types, exhaustive match
  • CLI + LSP + VS Code extension
  • 20-lesson tour, migration guide, 30 @superjs/types-* wrappers
  • Playground with server-side compile+run

Bench on ~14k LOC: cold compile ~81ms vs tsc typecheck ~721ms (not apples-to-apples — we codegen too).

Try: https://superjs.org/playground
Docs: https://superjs.org/docs
Repo: https://github.com/hbarve1/super-js

Happy to answer questions on interop (dynamic vs banning any), the LLVM roadmap, and where we deliberately cut scope (no DAP in 1.0).


lobste.rs (draft)

Title: SuperJS 1.0 – sound types for JavaScript without the TS complexity budget

Tags: javascript, typescript, compilers, programming

Body: (shorter than HN — link to Why SJS page)

SuperJS compiles .sjs to ES2022. We banned any and TS-only type features that break soundness; we added sum types and match. Compiler is from scratch, GPL-3.0.

https://superjs.org/docs/why


r/typescript (draft)

Title: SuperJS 1.0 GA — a sound alternative when TS's escape hatches hurt

Body:

If this isn't appropriate for r/typescript, mod please remove.

SuperJS isn't "TS with different syntax" — we removed features (any, intersections, conditionals) and added sum types + default null safety. Migration guide for common patterns: https://superjs.org/docs/migration

We'd love feedback from teams who've hit any-shaped holes in large codebases.

Documentation