Skip to main content

Handling untyped Luau

If your .luau source has no type annotations (no --!strict, no local x: number), the compiler still emits valid TypeScript, but the output is full of any and may not type-check under a strict tsconfig.

What gets any​

  • Top-level globals (local x = _G.something) are typed as any.
  • Anonymous tables ({ foo = 1 }) are typed as inline object literals, usually fine.
  • Untyped function parameters become any.

Options​

  1. Annotate the Luau source. The compiler picks up --!strict and individual local x: number annotations and propagates them through.

  2. Loosen the output tsconfig. Set "noImplicitAny": false and "strict": false on the emitted code. This is the right call for a one-time migration: get the project compiling, then incrementally re-tighten the settings as you add annotations.

  3. Hand-edit after compile. The output is normal TypeScript, git add it and edit. Source maps make this safe.

Recommendation​

For a real migration: start with --mode rbxts and a loose tsconfig, get the project building, then tighten settings file by file. Don't try to land a strict tsconfig in the same PR as the initial compile.