Typescript compile issue: Type 'string' is not assignable to type '"root"'.

[rickmzp]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and discussions and couldn’t find anything (or linked relevant results below)

Affected package

mdast-util-to-markdown

Steps to reproduce

With version 2.1.2:

import { toMarkdown } from 'mdast-util-to-markdown';

const tree = {
  type: 'root',
  children: [
    {type: 'paragraph', children: [{type: 'text', value: 'a'}]},
    {type: 'thematicBreak'},
    {type: 'paragraph', children: [{type: 'text', value: 'b'}]}
  ]
};

const markdown = toMarkdown(tree);
console.log(markdown);

Run with tsc case.ts

Actual behavior

case.ts:12:29 - error TS2345: Argument of type '{ type: string; children: ({ type: string; children: { type: string; value: string; }[]; } | { type: string; children?: undefined; })[]; }' is not assignable to parameter of type 'Nodes'.
  Type '{ type: string; children: ({ type: string; children: { type: string; value: string; }[]; } | { type: string; children?: undefined; })[]; }' is not assignable to type 'Root'.
    Types of property 'type' are incompatible.
      Type 'string' is not assignable to type '"root"'.

12 const markdown = toMarkdown(tree);
                               ~~~~


Found 1 error in case.ts:12

Expected behavior

Output of:

a

***

b

Runtime

[email protected], Typescript 5.8.3

Package manager

[email protected]

Operating system

macOS 15.4.1

Build and bundle tools

No response

[remcohaszing]

Add a type annotation.

+ import { Root } from 'mdast'
  import { toMarkdown } from 'mdast-util-to-markdown';

- const tree = {
+ const tree: Root = {
    type: 'root',
    children: [
      {type: 'paragraph', children: [{type: 'text', value: 'a'}]},
      {type: 'thematicBreak'},
      {type: 'paragraph', children: [{type: 'text', value: 'b'}]}
    ]
  };

  const markdown = toMarkdown(tree);
console.log(markdown);

[github-actions]

Hi! Thanks for reaching out! Because we treat issues as our backlog, we close issues that are questions since they don’t represent a task to be completed.

See our support docs for how and where to ask questions.

Thanks,
— bb