mdast-util-heading-style

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[mdast][] utility to get the style of a heading.

Contents

* What is this?
* When should I use this?
* Install
* Use
* API
* [headingStyle(node[, relative])](#headingstylenode-relative)
* Style
* Types
* Compatibility
* Security
* Related
* Contribute
* License

What is this?

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

``markdown


ATX uses hashes

Setext uses an underline
------------------------
`

When should I use this?

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

Install

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

`sh
npm install mdast-util-heading-style
`

In Deno with [esm.sh][esmsh]:

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

In browsers with [esm.sh][esmsh]:

`html

`

Use

`js
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'
`

API

This package exports the identifier [headingStyle][api-headingstyle].
There is no default export.

$3

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.

###### Parameters

* node ([Heading][heading])
— heading node to check
* style ([Style][api-style], optional)
— relative style

###### Returns

Style ([Style][api-style]) if it can be inferred, undefined otherwise.

$3

Style of heading (TypeScript type).

###### Type

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

Types

This package is fully typed with [TypeScript][].
It exports the additional type [Style][api-style].

Compatibility

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.

Security

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

Related

* mdast-normalize-headings
— make sure there is no more than a single top-level heading
* mdast-util-heading-range
— use headings as ranges

Contribute

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

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

License

[MIT][license] © [Titus Wormer][author]

[build-badge]: https://github.com/syntax-tree/mdast-util-heading-style/workflows/main/badge.svg

[build]: https://github.com/syntax-tree/mdast-util-heading-style/actions

[coverage-badge]: https://img.shields.io/codecov/c/github/syntax-tree/mdast-util-heading-style.svg

[coverage]: https://codecov.io/github/syntax-tree/mdast-util-heading-style

[downloads-badge]: https://img.shields.io/npm/dm/mdast-util-heading-style.svg

[downloads]: https://www.npmjs.com/package/mdast-util-heading-style

[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=mdast-util-heading-style

[size]: https://bundlejs.com/?q=mdast-util-heading-style

[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg

[backers-badge]: https://opencollective.com/unified/backers/badge.svg

[collective]: https://opencollective.com/unified

[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg

[chat]: https://github.com/syntax-tree/unist/discussions

[license]: license

[author]: https://wooorm.com

[npm]: https://docs.npmjs.com/cli/install

[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[esmsh]: https://esm.sh

[typescript]: https://www.typescriptlang.org

[health]: https://github.com/syntax-tree/.github

[contributing]: https://github.com/syntax-tree/.github/blob/main/contributing.md

[support]: https://github.com/syntax-tree/.github/blob/main/support.md

[coc]: https://github.com/syntax-tree/.github/blob/main/code-of-conduct.md

[mdast]: https://github.com/syntax-tree/mdast

[heading]: https://github.com/syntax-tree/mdast#heading

[xss]: https://en.wikipedia.org/wiki/Cross-site_scripting

[hast]: https://github.com/syntax-tree/hast

[remark-lint]: https://github.com/remarkjs/remark-lint

[api-headingstyle]: #headingstylenode-relative

[api-style]: #style