remark
unified processor with support for parsing from markdown and
serializing to markdown.
Contents
What is this?
This package is a unified processor with support for parsing markdown as
input and serializing markdown as output by using unified with
remark-parse and remark-stringify.
See the monorepo readme for info on what the remark ecosystem is.
When should I use this?
You can use this package when you want to use unified, have markdown as input,
and want markdown as output.
This package is a shortcut for
unified().use(remarkParse).use(remarkStringify).
When the input isn’t markdown (meaning you don’t need remark-parse) or the
output is not markdown (you don’t need remark-stringify), it’s recommended to
use unified directly.
When you want to inspect and format markdown files in a project on the command
line, you can use remark-cli.
Install
This package is ESM only.
In Node.js (version 16+), install with npm:
npm install remark
In Deno with esm.sh:
import {remark} from 'https://esm.sh/remark@15'
In browsers with esm.sh:
<script type="module">
import {remark} from 'https://esm.sh/remark@15?bundle'
</script>
Use
Say we have the following module example.js:
import {remark} from 'remark'
import remarkToc from 'remark-toc'
const doc = `
# Pluto
Pluto is a dwarf planet in the Kuiper belt.
## Contents
## History
### Discovery
In the 1840s, Urbain Le Verrier used Newtonian mechanics to predict the position of…
### Name and symbol
The name Pluto is for the Roman god of the underworld, from a Greek epithet for Hades…
### Planet X disproved
Once Pluto was found, its faintness and lack of a viewable disc cast doubt…
## Orbit
Pluto's orbital period is about 248 years…
`
const file = await remark()
.use(remarkToc, {heading: 'contents', tight: true})
.process(doc)
console.error(String(file))
…running that with node example.js yields:
# Pluto
Pluto is a dwarf planet in the Kuiper belt.
## Contents
* [History](https://www.npmjs.com/package/remark#history)
* [Discovery](https://www.npmjs.com/package/remark#discovery)
* [Name and symbol](https://www.npmjs.com/package/remark#name-and-symbol)
* [Planet X disproved](https://www.npmjs.com/package/remark#planet-x-disproved)
* [Orbit](https://www.npmjs.com/package/remark#orbit)
## History
### Discovery
In the 1840s, Urbain Le Verrier used Newtonian mechanics to predict the position of…
### Name and symbol
The name Pluto is for the Roman god of the underworld, from a Greek epithet for Hades…
### Planet X disproved
Once Pluto was found, its faintness and lack of a viewable disc cast doubt…
## Orbit
Pluto's orbital period is about 248 years…
API
This package exports the identifier remark.
There is no default export.
remark()
Create a new unified processor that already uses
remark-parse and remark-stringify.
You can add more plugins with use.
See unified for more information.
Examples
Example: checking markdown
The following example checks that markdown code style is consistent and follows
some best practices:
import {remark} from 'remark'
import remarkPresetLintConsistent from 'remark-preset-lint-consistent'
import remarkPresetLintRecommended from 'remark-preset-lint-recommended'
import {reporter} from 'vfile-reporter'
const file = await remark()
.use(remarkPresetLintConsistent)
.use(remarkPresetLintRecommended)
.process('1) Hello, _Jupiter_ and *Neptune*!')
console.error(reporter(file))
Yields:
warning Missing newline character at end of file final-newline remark-lint
1:1-1:35 warning Marker style should be `.` ordered-list-marker-style remark-lint
1:4 warning Incorrect list-item indent: add 1 space list-item-indent remark-lint
1:25-1:34 warning Emphasis should use `_` as a marker emphasis-marker remark-lint
⚠ 4 warnings
Example: passing options to remark-stringify
When you use remark-stringify manually you can pass options to use.
Because remark-stringify is already used in remark, that’s not possible.
To define options for remark-stringify, you can instead pass options to
data:
import {remark} from 'remark'
const doc = `
# Moons of Neptune
1. Naiad
2. Thalassa
3. Despine
4. …
`
const file = await remark()
.data('settings', {
bulletOrdered: ')',
incrementListMarker: false,
setext: true
})
.process(doc)
console.log(String(file))
Yields:
Moons of Neptune
================
1) Naiad
1) Thalassa
1) Despine
1) …
Syntax
Markdown is parsed and serialized according to CommonMark.
Other plugins can add support for syntax extensions.
Syntax tree
The syntax tree used in remark is mdast.
Types
This package is fully typed with TypeScript.
There are no extra exported types.
It also registers Settings with unified.
If you’re passing options with .data('settings', …), make sure to import this
package somewhere in your types, as that registers the fields.
/// <reference types="remark" />
import {unified} from 'unified'
// @ts-expect-error: `thisDoesNotExist` is not a valid option.
unified().data('settings', {thisDoesNotExist: false})
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, remark@^15, compatible
with Node.js 16.
Security
As markdown can be turned into HTML and improper use of HTML can open you up to
cross-site scripting (XSS) attacks, use of remark can be unsafe.
When going to HTML, you will combine remark with rehype, in which case
you should use rehype-sanitize.
Use of remark plugins could also open you up to other attacks.
Carefully assess each plugin and the risks involved in using them.
For info on how to submit a report, see our security policy.
Contribute
See contributing.md in remarkjs/.github for ways
to get started.
See support.md for ways to get help.
Join us in Discussions to chat with the community and contributors.
This project has a code of conduct.
By interacting with this repository, organization, or community you agree to
abide by its terms.
Sponsor
Support this effort and give back by sponsoring on OpenCollective!
License
MIT © Titus Wormer
