mdast-util-gfm-autolink-literal

What is mdast-util-gfm-autolink-literal?

The mdast-util-gfm-autolink-literal npm package is a utility to support GitHub Flavored Markdown (GFM) autolink literals in mdast syntax trees. It helps parse and serialize autolink literals like URLs and email addresses directly in Markdown documents, making them clickable links without additional markup.

What are mdast-util-gfm-autolink-literal's main functionalities?

Parsing GFM Autolink Literals

This code sample demonstrates how to set up a processor using Unified with the remark-parse and remark-gfm plugins, enhanced by mdast-util-gfm-autolink-literal to automatically parse URLs written in plain text as autolink literals in the Markdown document.

import { unified } from 'unified';
import markdown from 'remark-parse';
import gfm from 'remark-gfm';
import gfmAutolinkLiteral from 'mdast-util-gfm-autolink-literal';

const processor = unified()
  .use(markdown)
  .use(gfm)
  .use(gfmAutolinkLiteral);

const tree = processor.parse('See https://example.com for more info.');
console.log(tree);

Other packages similar to mdast-util-gfm-autolink-literal

remark-gfm

This package is a plugin for remark that supports all GFM features, including autolinks, tables, strikethrough, and task lists. It is broader in scope compared to mdast-util-gfm-autolink-literal, which specifically focuses on autolink literals.

micromark-extension-gfm-autolink-literal

Similar to mdast-util-gfm-autolink-literal, this package is a micromark extension to parse and serialize GFM autolink literals. It serves a similar purpose but is used in the micromark ecosystem, which is the underlying system for remark.

README

mdast-util-gfm-autolink-literal

mdast extensions to parse and serialize GFM autolink literals.

Contents

• What is this?
• When to use this
• Install
• Use
• API
  • gfmAutolinkLiteralFromMarkdown()
  • gfmAutolinkLiteralToMarkdown()
• HTML
• Syntax
• Syntax tree
• Types
• Compatibility
• Related
• Contribute
• License

What is this?

This package contains two extensions that add support for GFM autolink literals syntax in markdown to mdast. These extensions plug into mdast-util-from-markdown (to support parsing GFM autolinks in markdown into a syntax tree) and mdast-util-to-markdown (to support serializing GFM autolinks in syntax trees to markdown).

GitHub employs different algorithms to autolink: one at parse time and one at transform time (similar to how @mentions are done at transform time). This difference can be observed because character references and escapes are handled differently. But also because issues/PRs/comments omit (perhaps by accident?) the second algorithm for www., http://, and https:// links (but not for email links).

As the corresponding micromark extension micromark-extension-gfm-autolink-literal is a syntax extension, it can only perform the first algorithm. The tree extension gfmAutolinkLiteralFromMarkdown from this package can perform the second algorithm, and as they are combined, both are done.

When to use this

You can use these extensions when you are working with mdast-util-from-markdown and mdast-util-to-markdown already.

When working with mdast-util-from-markdown, you must combine this package with micromark-extension-gfm-autolink-literal.

When you don’t need a syntax tree, you can use micromark directly with micromark-extension-gfm-autolink-literal.

When you are working with syntax trees and want all of GFM, use mdast-util-gfm instead.

All these packages are used remark-gfm, which focusses on making it easier to transform content by abstracting these internals away.

This utility does not handle how markdown is turned to HTML. That’s done by mdast-util-to-hast.

Install

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

npm install mdast-util-gfm-autolink-literal

In Deno with esm.sh:

import {gfmAutolinkLiteralFromMarkdown, gfmAutolinkLiteralToMarkdown} from 'https://esm.sh/mdast-util-gfm-autolink-literal@2'

In browsers with esm.sh:

<script type="module">
  import {gfmAutolinkLiteralFromMarkdown, gfmAutolinkLiteralToMarkdown} from 'https://esm.sh/mdast-util-gfm-autolink-literal@2?bundle'
</script>

Use

Say our document example.md contains:

www.example.com, https://example.com, and [e-mail].

…and our module example.js looks as follows:

import fs from 'node:fs/promises'
import {gfmAutolinkLiteral} from 'micromark-extension-gfm-autolink-literal'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {
  gfmAutolinkLiteralFromMarkdown,
  gfmAutolinkLiteralToMarkdown
} from 'mdast-util-gfm-autolink-literal'
import {toMarkdown} from 'mdast-util-to-markdown'

const doc = await fs.readFile('example.md')

const tree = fromMarkdown(doc, {
  extensions: [gfmAutolinkLiteral()],
  mdastExtensions: [gfmAutolinkLiteralFromMarkdown()]
})

console.log(tree)

const out = toMarkdown(tree, {extensions: [gfmAutolinkLiteralToMarkdown()]})

console.log(out)

…now running node example.js yields (positional info removed for brevity):

{
  type: 'root',
  children: [
    {
      type: 'paragraph',
      children: [
        {
          type: 'link',
          title: null,
          url: 'http://www.example.com',
          children: [{type: 'text', value: 'www.example.com'}]
        },
        {type: 'text', value: ', '},
        {
          type: 'link',
          title: null,
          url: 'https://example.com',
          children: [{type: 'text', value: 'https://example.com'}]
        },
        {type: 'text', value: ', and '},
        {
          type: 'link',
          title: null,
          url: 'mailto:[e-mail]',
          children: [{type: 'text', value: '[e-mail]'}]
        },
        {type: 'text', value: '.'}
      ]
    }
  ]
}

[www.example.com](http://www.example.com), <https://example.com>, and <[e-mail]>.

API

This package exports the identifiers gfmAutolinkLiteralFromMarkdown and gfmAutolinkLiteralToMarkdown. There is no default export.

gfmAutolinkLiteralFromMarkdown()

Create an extension for mdast-util-from-markdown to enable GFM autolink literals in markdown.

Returns

Extension for mdast-util-to-markdown to enable GFM autolink literals (FromMarkdownExtension).

gfmAutolinkLiteralToMarkdown()

Create an extension for mdast-util-to-markdown to enable GFM autolink literals in markdown.

Returns

Extension for mdast-util-to-markdown to enable GFM autolink literals (ToMarkdownExtension).

HTML

This utility does not handle how markdown is turned to HTML. That’s done by mdast-util-to-hast.

Syntax

See Syntax in micromark-extension-gfm-autolink-literal.

Syntax tree

There are no interfaces added to mdast by this utility, as it reuses the existing Link interface.

Types

This package is fully typed with TypeScript. It does not export additional types.

The Link type of the mdast nodes is exposed from @types/mdast.

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-gfm-autolink-literal@^2, compatible with Node.js 16.

This utility works with mdast-util-from-markdown version 2+ and mdast-util-to-markdown version 2+.

Related

• remarkjs/remark-gfm — remark plugin to support GFM
• syntax-tree/mdast-util-gfm — same but all of GFM (autolink literals, footnotes, strikethrough, tables, tasklists)
• micromark/micromark-extension-gfm-autolink-literal — micromark extension to parse GFM autolink literals

Contribute

See contributing.md in syntax-tree/.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