remark-lint-no-undefined-references

remark-lint rule to warn when undefined definitions are referenced.

Contents

• What is this?
• When should I use this?
• Presets
• Install
• Use
• API
  • unified().use(remarkLintNoUndefinedReferences[, options])
  • Options
• Recommendation
• Examples
• Compatibility
• Contribute
• License

What is this?

This package checks that referenced definitions are defined.

When should I use this?

You can use this package to check for broken references.

Presets

This plugin is included in the following presets:

| Preset | Options | | - | - | | remark-preset-lint-recommended | |

Install

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

npm install remark-lint-no-undefined-references

In Deno with esm.sh:

import remarkLintNoUndefinedReferences from 'https://esm.sh/remark-lint-no-undefined-references@5'

In browsers with esm.sh:

<script type="module">
  import remarkLintNoUndefinedReferences from 'https://esm.sh/remark-lint-no-undefined-references@5?bundle'
</script>

Use

On the API:

import remarkLint from 'remark-lint'
import remarkLintNoUndefinedReferences from 'remark-lint-no-undefined-references'
import remarkParse from 'remark-parse'
import remarkStringify from 'remark-stringify'
import {read} from 'to-vfile'
import {unified} from 'unified'
import {reporter} from 'vfile-reporter'

const file = await read('example.md')

await unified()
  .use(remarkParse)
  .use(remarkLint)
  .use(remarkLintNoUndefinedReferences)
  .use(remarkStringify)
  .process(file)

console.error(reporter(file))

On the CLI:

remark --frail --use remark-lint --use remark-lint-no-undefined-references .

On the CLI in a config file (here a package.json):

 …
 "remarkConfig": {
   "plugins": [
     …
     "remark-lint",
+    "remark-lint-no-undefined-references",
     …
   ]
 }
 …

API

This package exports no identifiers. It exports the TypeScript type Options. The default export is remarkLintNoUndefinedReferences.

unified().use(remarkLintNoUndefinedReferences[, options])

Warn when undefined definitions are referenced.

Parameters

• options (Options, optional) — configuration

Returns

Transform (Transformer from unified).

Options

Configuration (TypeScript type).

Fields

• allow (Array<RegExp | string>, optional) — list of values to allow between [ and ]
• allowShortcutLink (boolean, default: false) — allow shortcut references, which are just brackets such as [text]

Recommendation

Shortcut references use an implicit syntax that could also occur as plain text. To illustrate, it is reasonable to expect an author adding […] to abbreviate some text somewhere in a document:

> Some […] quote.

This isn’t a problem, but it might become one when an author later adds a definition:

Some new text […][].

[…]: #read-more

The second author might expect only their newly added text to form a link, but their changes also result in a link for the text by the first author.

Examples

ok.md

In

[Mercury][] is the first planet from the Sun and the smallest in the Solar
System.

Venus is the second planet from the [Sun.

Earth is the third planet from the \[Sun] and the only astronomical object
known to harbor life\.

Mars is the fourth planet from the Sun: [].

[mercury]: https://example.com/mercury/

Out

No messages.

not-ok.md

In

[Mercury] is the first planet from the Sun and the smallest in the Solar
System.

[Venus][] is the second planet from the Sun.

[Earth][earth] is the third planet from the Sun and the only astronomical
object known to harbor life.

![Mars] is the fourth planet from the Sun in the [Solar
System].

> Jupiter is the fifth planet from the Sun and the largest in the [Solar
> System][].

[Saturn][ is the sixth planet from the Sun and the second-largest
in the Solar System, after Jupiter.

[*Uranus*][] is the seventh planet from the Sun.

[Neptune][neptune][more] is the eighth and farthest planet from the Sun.

Out

1:1-1:10: Unexpected reference to undefined definition, expected corresponding definition (`mercury`) for a link or escaped opening bracket (`\[`) for regular text
4:1-4:10: Unexpected reference to undefined definition, expected corresponding definition (`venus`) for a link or escaped opening bracket (`\[`) for regular text
6:1-6:15: Unexpected reference to undefined definition, expected corresponding definition (`earth`) for a link or escaped opening bracket (`\[`) for regular text
9:2-9:8: Unexpected reference to undefined definition, expected corresponding definition (`mars`) for an image or escaped opening bracket (`\[`) for regular text
9:50-10:8: Unexpected reference to undefined definition, expected corresponding definition (`solar system`) for a link or escaped opening bracket (`\[`) for regular text
12:67-13:12: Unexpected reference to undefined definition, expected corresponding definition (`solar > system`) for a link or escaped opening bracket (`\[`) for regular text
15:1-15:9: Unexpected reference to undefined definition, expected corresponding definition (`saturn`) for a link or escaped opening bracket (`\[`) for regular text
18:1-18:13: Unexpected reference to undefined definition, expected corresponding definition (`*uranus*`) for a link or escaped opening bracket (`\[`) for regular text
20:1-20:19: Unexpected reference to undefined definition, expected corresponding definition (`neptune`) for a link or escaped opening bracket (`\[`) for regular text
20:19-20:25: Unexpected reference to undefined definition, expected corresponding definition (`more`) for a link or escaped opening bracket (`\[`) for regular text

ok-allow.md

When configured with { allow: [ '…' ] }.

In

Mercury is the first planet from the Sun and the smallest in the Solar
System. […]

Out

No messages.

source.md

When configured with { allow: [ { source: '^mer' }, 'venus' ] }.

In

[Mercury][] is the first planet from the Sun and the smallest in the Solar
System.

[Venus][] is the second planet from the Sun.

Out

No messages.

gfm.md

In

👉 Note: this example uses GFM (remark-gfm).

Mercury[^mercury] is the first planet from the Sun and the smallest in the
Solar System.

[^venus]:
    **Venus** is the second planet from the Sun.

Out

1:8-1:18: Unexpected reference to undefined definition, expected corresponding definition (`mercury`) for a footnote or escaped opening bracket (`\[`) for regular text

allow-shortcut-link.md

When configured with { allowShortcutLink: true }.

In

[Mercury] is the first planet from the Sun and the smallest in the Solar
System.

[Venus][] is the second planet from the Sun.

[Earth][earth] is the third planet from the Sun and the only astronomical object
known to harbor life.

Out

4:1-4:10: Unexpected reference to undefined definition, expected corresponding definition (`venus`) for a link or escaped opening bracket (`\[`) for regular text
6:1-6:15: Unexpected reference to undefined definition, expected corresponding definition (`earth`) for a link or escaped opening bracket (`\[`) for regular text

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-lint-no-undefined-references@5, compatible with Node.js 16.

Contribute

See contributing.md in remarkjs/.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