remark-extract-toc

This is a remark plugin which attaches a
document's table of contents to the VFile.

How to install

``sh
yarn add @stefanprobst/remark-extract-toc
`

How to use

`js
import { remark } from 'remark'
import withSlugs from 'remark-slug'
import withToc from '@stefanprobst/remark-extract-toc'

const processor = remark().use(withSlugs).use(withToc)

const { data, contents } = processor.processSync(doc)

console.dir(data.toc, { depth: null })
`

The table of contents will be attached to the resulting VFile's data.toc
property. It has the following shape:

`ts
interface TocEntry {
value: string
depth: number
id?: string
children?: Array
}

type Toc = Array
`

Note that this plugin does _not_ generate any ids, you will probably want to
combine it with remark-slug.

How you render the table of contents is up to you.

How to use with MDX

When transforming MDX documents, you can expose the table of contents as a named
export, which defaults to tableOfContents.

`js
import { compile } from '@mdx-js/mdx'
import withSlugs from 'remark-slug'
import withToc from '@stefanprobst/remark-extract-toc'
import withTocExport from '@stefanprobst/remark-extract-toc/mdx'

async function run() {
const file = await compile(doc, {
remarkPlugins: [
withSlugs,
withToc,
withTocExport,
/* Optionally, provide a custom name for the export. /
// [withTocExport, { name: 'toc' }],
],
})

console.log(String(file))
}

run()
`

If you are using TypeScript, you can add typings with:

`js
/* mdx.d.ts (should be referenced in tsconfig.json#include) /
declare module '*.mdx' {
import type { MDXProps } from 'mdx/types'
import type { Toc } from '@stefanprobst/remark-extract-toc'

export const tableOfContents: Toc
export default function MDXContent(props: MDXProps): JSX.Element
}
``