Project: syntax-tree/mdast-util-heading-style

Package: mdast-util-heading-style@2.0.0

  1. mdast utility to get the style of a heading
  1. markdown 156
  2. util 146
  3. utility 142
  4. unist 132
  5. mdast 90
  6. mdast-util 30
  7. heading 26
  8. node 24
  9. style 11


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mdast utility to get the style of a heading.


What is this?

This package is a tiny utility to figure out if a heading was written as ATX or as setext.

## ATX uses hashes

Setext uses an underline

When should I use this?

Probably not a lot! It’s used in remark-lint.


This package is ESM only. In Node.js (version 16+), install with npm:

npm install mdast-util-heading-style

In Deno with esm.sh:

import {headingStyle} from 'https://esm.sh/mdast-util-heading-style@3'

In browsers with esm.sh:

<script type="module">
  import {headingStyle} from 'https://esm.sh/mdast-util-heading-style@3?bundle'


import {unified} from 'unified'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {headingStyle} from 'mdast-util-heading-style'

headingStyle(fromMarkdown('# ATX').children[0]) // => 'atx'
headingStyle(fromMarkdown('# ATX #\n').children[0]) // => 'atx-closed'
headingStyle(fromMarkdown('ATX\n===').children[0]) // => 'setext'

headingStyle(fromMarkdown('### ATX').children[0]) // => undefined
headingStyle(fromMarkdown('### ATX').children[0], 'setext') // => 'setext'


This package exports the identifier headingStyle. There is no default export.

headingStyle(node[, relative])

Get the heading style of a heading, optionally relative to a preferred style.

This is because ATX headings with a depth of three or more could be considered setext.


Style (Style) if it can be inferred, undefined otherwise.


Style of heading (TypeScript type).

type Style = 'atx' | 'atx-closed' | 'setext'


This package is fully typed with TypeScript. It exports the additional type Style.


Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, mdast-util-heading-style@^3, compatible with Node.js 16.


Use of mdast-util-heading-style does not involve hast so there are no openings for cross-site scripting (XSS) attacks.


See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.


MIT © Titus Wormer