Skip to content

syntax-tree/mdast-comment-marker

Repository files navigation

mdast-comment-marker

Build Coverage Downloads Size Sponsors Backers Chat

mdast utility to parse comment markers.

Contents

What is this?

This package is a utility that tries to parse a structured marker from a comment.

When should I use this?

Comments are a hidden part of markdown, so they can be used as processing instructions. For example, this utility is used in remark-lint to control whether lint rules are turned on or ignored, and by mdast-zone to replace sections between two markers.

Install

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

npm install mdast-comment-marker

In Deno with esm.sh:

import {commentMarker} from 'https://esm.sh/mdast-comment-marker@3'

In browsers with esm.sh:

<script type="module">
  import {commentMarker} from 'https://esm.sh/mdast-comment-marker@3?bundle'
</script>

Use

import {commentMarker} from 'mdast-comment-marker'

console.log(commentMarker({type: 'html', value: '<!--foo-->'}));

console.log(commentMarker({
  type: 'html',
  value: '<!--foo bar baz=12.4 qux="test test" quux=\'false\'-->'
}));

console.log(commentMarker({type: 'html', value: '<!doctype html>'}));

// Also supports MDX expressions:
console.log(commentMarker({
  type: 'mdxFlowExpression',
  value: '/* lint disable heading-style */'
}));

Yields:

{
  name: 'foo',
  attributes: '',
  parameters: {},
  node: { type: 'html', value: '<!--foo-->' }
}
{
  name: 'foo',
  attributes: `bar baz=12.4 qux="test test" quux='false'`,
  parameters: { bar: true, baz: 12.4, qux: 'test test', quux: false },
  node: {
    type: 'html',
    value: `<!--foo bar baz=12.4 qux="test test" quux='false'-->`
  }
}
undefined
{
  name: 'lint',
  attributes: 'disable heading-style',
  parameters: { disable: true, 'heading-style': true },
  node: {
    type: 'mdxFlowExpression',
    value: '/* lint disable heading-style */'
  }
}

API

This package exports the identifier commentMarker. There is no default export.

commentMarker(value)

Parse a comment marker.

Parameters
  • value (unknown) — thing to parse, typically Node
Returns

Info (Marker) when applicable or undefined.

Marker

Comment marker (TypeScript type).

Properties
  • name (string) — name of marker
  • attributes (string) — value after name
  • parameters (MarkerParameters) — parsed attributes
  • node (Node) — reference to given node

MarkerParameters

Parameters (TypeScript type).

type
type MarkerParameters = Record<string, MarkerParameterValue>

MarkerParameterValue

Value (TypeScript type).

If it looks like a number (to JavaScript), it’s cast as number. The strings true and false are turned into their corresponding booleans. The empty string is also considered the true boolean.

type
type MarkerParameterValue = number | string | boolean

Types

This package is fully typed with TypeScript. This package exports the types Marker, MarkerParameters, and MarkerParameterValue

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-comment-marker@^3, compatible with Node.js 16.

Security

Use of mdast-comment-marker does not involve hast, user content, or change the tree, so there are no openings for cross-site scripting (XSS) attacks.

Related

  • mdast-zone — change or replace a section marked by comments

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