Mdast-util-heading-style NPM

mdast-util-heading-style

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.

Install

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'
</script>

Use

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. 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.

Parameters

node (Heading) — heading node to check
style (Style, optional) — relative style

Returns

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

`Style`

Style of heading (TypeScript type).

Type

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

Types

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