remark-parse

What is remark-parse?

The remark-parse package is a plugin for the Remark processor that parses Markdown content into a syntax tree. It is part of the unified ecosystem, which provides a way to parse, transform, and stringify content using abstract syntax trees (ASTs).

What are remark-parse's main functionalities?

Parsing Markdown

This feature allows you to parse Markdown content and transform it into an abstract syntax tree (AST). The code sample demonstrates how to use remark-parse with the remark library to parse a simple Markdown string.

const remark = require('remark');
const parse = require('remark-parse');

remark().use(parse).process('# Hello world!', function(err, file) {
  if (err) throw err;
  console.log(file);
});

Extensible Markdown Parsing

remark-parse can be extended with plugins to handle custom Markdown syntax. In this example, the 'remark-math' plugin is used to parse mathematical expressions within the Markdown content.

const remark = require('remark');
const parse = require('remark-parse');
const math = require('remark-math');

remark().use(parse).use(math).process('Euler's identity: $e^{i\pi} + 1 = 0$', function(err, file) {
  if (err) throw err;
  console.log(file);
});

Other packages similar to remark-parse

markdown-it

markdown-it is a Markdown parser with a similar goal to remark-parse, but it is implemented differently. It is often used for its speed and extensibility with plugins, and it can output HTML directly instead of an AST.

marked

marked is another Markdown parser that is known for being fast and lightweight. It is less extensible than remark-parse but can be a good choice for simpler use cases where a full AST is not required.

README

remark-parse

remark plugin to add support for parsing markdown input.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • unified().use(remarkParse)
• Examples
  • Example: support GFM and frontmatter
  • Example: turning markdown into a man page
• Syntax
• Syntax tree
• Types
• Compatibility
• Security
• Contribute
• Sponsor
• License

What is this?

This package is a unified (remark) plugin that defines how to take markdown as input and turn it into a syntax tree.

This plugin is built on mdast-util-from-markdown, which in turn uses micromark for parsing markdown into tokens and turns those into mdast syntax trees. remark focusses on making it easier to transform content by abstracting such internals away.

unified is a project that transforms content with abstract syntax trees (ASTs). remark adds support for markdown to unified. mdast is the markdown AST that remark uses. micromark is the markdown parser we use. This is a remark plugin that defines how input markdown is turned into mdast.

When should I use this?

This plugin adds support to unified for parsing markdown. You can alternatively use remark instead, which combines unified, this plugin, and remark-stringify.

You can combine this plugin with other plugins to add syntax extensions. Notable examples that deeply integrate with it are remark-gfm, remark-mdx, remark-frontmatter, remark-math, and remark-directive. You can also use any other remark plugin after remark-parse.

If you just want to turn markdown into HTML (with maybe a few extensions), we recommend micromark instead. If you want to handle syntax trees manually, you can use mdast-util-from-markdown.

Install

This package is ESM only. In Node.js (version 12.20+, 14.14+, or 16.0+), install with npm:

npm install remark-parse

In Deno with esm.sh:

import remarkParse from 'https://esm.sh/remark-parse@10'

In browsers with esm.sh:

<script type="module">
  import remarkParse from 'https://esm.sh/remark-parse@10?bundle'
</script>

Use

Say we have the following module example.js:

import {unified} from 'unified'
import remarkParse from 'remark-parse'
import remarkGfm from 'remark-gfm'
import remarkRehype from 'remark-rehype'
import rehypeStringify from 'rehype-stringify'

main()

async function main() {
  const file = await unified()
    .use(remarkParse)
    .use(remarkGfm)
    .use(remarkRehype)
    .use(rehypeStringify)
    .process('# Hi\n\n*Hello*, world!')

  console.log(String(file))
}

Running that with node example.js yields:

<h1>Hi</h1>
<p><em>Hello</em>, world!</p>

API

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

unified().use(remarkParse)

Add support for parsing markdown input. There are no options.

Examples

Example: support GFM and frontmatter

We support CommonMark by default. Non-standard markdown extensions can be enabled with plugins. The following example adds support for GFM features (autolink literals, footnotes, strikethrough, tables, tasklists) and frontmatter (YAML):

import {unified} from 'unified'
import remarkParse from 'remark-parse'
import remarkFrontmatter from 'remark-frontmatter'
import remarkGfm from 'remark-gfm'
import remarkRehype from 'remark-rehype'
import rehypeStringify from 'rehype-stringify'

main()

async function main() {
  const file = await unified()
    .use(remarkParse)
    .use(remarkFrontmatter)
    .use(remarkGfm)
    .use(remarkRehype)
    .use(rehypeStringify)
    .process('---\nlayout: home\n---\n\n# Hi ~~Mars~~Venus!')

  console.log(String(file))
}

Yields:

<h1>Hi <del>Mars</del>Venus!</h1>

Example: turning markdown into a man page

Man pages (short for manual pages) are a way to document CLIs (example: type man git-log in your terminal). They use an old markup format called roff. There’s a remark plugin, remark-man, that can serialize as roff. The following example turns markdown into man pages by using unified with remark-parse and remark-man:

import {unified} from 'unified'
import remarkParse from 'remark-parse'
import remarkMan from 'remark-man'

main()

async function main() {
  const file = await unified()
    .use(remarkParse)
    .use(remarkMan)
    .process('# titan(7) -- largest moon of saturn\n\nTitan is the largest moon…')

  console.log(String(file))
}

Yields:

.TH "TITAN" "7" "November 2021" "" ""
.SH "NAME"
\fBtitan\fR - largest moon of saturn
.P
Titan is the largest moon…

Syntax

Markdown is parsed according to CommonMark. Other plugins can add support for syntax extensions. If you’re interested in extending markdown, more information is available in micromark’s readme.

Syntax tree

The syntax tree format used in remark is mdast.

Types

This package is fully typed with TypeScript. There are no extra exported types.

Compatibility

Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 12.20+, 14.14+, and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.

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 likely 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!

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License

MIT © Titus Wormer