rehype-shift-heading

rehype plugin to change the rank of headings.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • unified().use(rehypeShiftHeading[, options])
  • Options
• Types
• Compatibility
• Security
• Related
• Contribute
• License

What is this?

This package is a unified (rehype) plugin to change the rank (also known as depth or level) of headings (so <h1> through <h6>). You can increase (by passing a positive number) or decrease (negative number) all headings.

unified is a project that transforms content with abstract syntax trees (ASTs). rehype adds support for HTML to unified. hast is the HTML AST that rehype uses. This is a rehype plugin that changes headings in the tree.

When should I use this?

This plugin is particularly useful when merging documents into each other. For example, when injecting a readme.md that starts with an <h1> into a site that uses an <h1> for the title of the website. This plugin can be used to shift all the headings inside the readme.

This plugin is built on hast-util-shift-heading, which does the work on syntax trees. rehype focusses on making it easier to transform content by abstracting such internals away.

Install

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

npm install rehype-shift-heading

In Deno with esm.sh:

import rehypeShiftHeading from 'https://esm.sh/rehype-shift-heading@2'

In browsers with esm.sh:

<script type="module">
  import rehypeShiftHeading from 'https://esm.sh/rehype-shift-heading@2?bundle'
</script>

Use

Say our module example.js looks as follows:

import {rehype} from 'rehype'
import rehypeShiftHeading from 'rehype-shift-heading'

const file = await rehype()
  .data('settings', {fragment: true})
  .use(rehypeShiftHeading, {shift: 1})
  .process('<h1>Alpha!</h1>')

console.log(String(file))

Now, running node example yields:

<h2>Alpha!</h2>

API

This package exports no identifiers. The default export is rehypeShiftHeading.

unified().use(rehypeShiftHeading[, options])

Change the rank (depth, level) of headings.

Does not shift past h1 and h6.

Parameters

• options (Options, optional) — configuration

Returns

Transform (Transformer).

Options

Configuration (TypeScript type).

Fields

• shift (number, default: 0) — number to shift headings; can be negative to decrease heading levels

Types

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

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, rehype-shift-heading@^2, compatible with Node.js 16.

This plugin works with rehype-parse version 1+, rehype-stringify version 1+, rehype version 1+, and unified version 4+.

Security

Use of rehype-shift-heading is safe.

Related

• rehype-slug — add ids to headings
• rehype-autolink-headings — add links to headings
• rehype-headings-normalize — normalizes headlines by shifting to a minimum level and closing gaps

Contribute

See contributing.md in rehypejs/.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.

License

MIT © Titus Wormer