For AI agents: the complete documentation index is available at /llms.txt, the full documentation bundle is available at /llms-full.txt, and this page is available as Markdown at /reference/control/todo.md.

todo

Marks a code path you intend to implement later and throws if execution reaches it.

return todo('waiting on schema decision')

Usage

todo(message?)

Use todo as an explicit, type-safe placeholder while work is incomplete. Its never return type allows it in any expression position, but it always throws at runtime. Use unimplemented for intentionally unsupported behavior and unreachable for logically impossible paths.

import { todo } from 'massaman'
// or:  import { todo } from 'massaman/control'

function parseConfig(raw: string): Config {
  return todo('waiting on schema decision')
}

Parameters

messagestringoptional

optional context appended to the thrown error message.

Returns

never returns; the function always throws.

never

Throws

An Error with not yet implemented, optionally followed by message.

See also