mdast-util-gfm-strikethrough

mdast extensions to parse and serialize GFM strikethrough.

Contents

• What is this?
• When to use this
• Install
• Use
• API
  • gfmStrikethroughFromMarkdown()
  • gfmStrikethroughToMarkdown()
• HTML
• Syntax
• Syntax tree
  • Nodes
  • Content model
• Types
• Compatibility
• Related
• Contribute
• License

What is this?

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

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-strikethrough.

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

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. If you want a different element, you should configure that utility.

Install

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

npm install mdast-util-gfm-strikethrough

In Deno with esm.sh:

import {gfmStrikethroughFromMarkdown, gfmStrikethroughToMarkdown} from 'https://esm.sh/mdast-util-gfm-strikethrough@2'

In browsers with esm.sh:

<script type="module">
  import {gfmStrikethroughFromMarkdown, gfmStrikethroughToMarkdown} from 'https://esm.sh/mdast-util-gfm-strikethrough@2?bundle'
</script>

Use

Say our document example.md contains:

*Emphasis*, **importance**, and ~~strikethrough~~.

…and our module example.js looks as follows:

import fs from 'node:fs/promises'
import {gfmStrikethrough} from 'micromark-extension-gfm-strikethrough'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {gfmStrikethroughFromMarkdown, gfmStrikethroughToMarkdown} from 'mdast-util-gfm-strikethrough'
import {toMarkdown} from 'mdast-util-to-markdown'

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

const tree = fromMarkdown(doc, {
  extensions: [gfmStrikethrough()],
  mdastExtensions: [gfmStrikethroughFromMarkdown()]
})

console.log(tree)

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

console.log(out)

Now, running node example yields:

{
  type: 'root',
  children: [
    {
      type: 'paragraph',
      children: [
        {type: 'emphasis', children: [{type: 'text', value: 'Emphasis'}]},
        {type: 'text', value: ', '},
        {type: 'strong', children: [{type: 'text', value: 'importance'}]},
        {type: 'text', value: ', and '},
        {type: 'delete', children: [{type: 'text', value: 'strikethrough'}]},
        {type: 'text', value: '.'}
      ]
    }
  ]
}

*Emphasis*, **importance**, and ~~strikethrough~~.

API

This package exports the identifiers gfmStrikethroughFromMarkdown and gfmStrikethroughToMarkdown. There is no default export.

gfmStrikethroughFromMarkdown()

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

Returns

Extension for mdast-util-from-markdown to enable GFM strikethrough (FromMarkdownExtension).

gfmStrikethroughToMarkdown()

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

Returns

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

HTML

This utility does not handle how markdown is turned to HTML. That’s done by mdast-util-to-hast. If you want a different element, you should configure that utility.

Syntax

See Syntax in micromark-extension-gfm-strikethrough.

Syntax tree

The following interfaces are added to mdast by this utility.

Nodes

Delete

interface Delete <: Parent {
  type: 'delete'
  children: [TransparentContent]
}

Delete (Parent) represents contents that are no longer accurate or no longer relevant.

Delete can be used where phrasing content is expected. Its content model is transparent content.

For example, the following markdown:

~~alpha~~

Yields:

{
  type: 'delete',
  children: [{type: 'text', value: 'alpha'}]
}

Content model

PhrasingContent (GFM strikethrough)

type PhrasingContentGfm = Delete | PhrasingContent

Types

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

The Delete type of the mdast node 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-strikethrough@^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-strikethrough — micromark extension to parse GFM strikethrough

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