remark-lint-no-undefined-references

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[remark-lint][github-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])](#unifieduseremarklintnoundefinedreferences-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][github-gist-esm].
In Node.js (version 16+),
install with [npm][npm-install]:

``sh
npm install remark-lint-no-undefined-references
`

In Deno with [esm.sh][esm-sh]:

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

In browsers with [esm.sh][esm-sh]:

`html

`

Use

On the API:

`js
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:

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

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

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

API

This package exports no identifiers.
It exports the [TypeScript][typescript] type
[Options][api-options].
The default export is
[remarkLintNoUndefinedReferences][api-remark-lint-no-undefined-references].

$3

Warn when undefined definitions are referenced.

###### Parameters

* options ([Options][api-options], optional)
— configuration

###### Returns

Transform ([Transformer from unified][github-unified-transformer]).

$3

Configuration (TypeScript type).

###### Fields

* allow (Array, 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:

`markdown
> Some […] quote.
`

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

`markdown
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

`markdown
[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

`markdown
[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

`text
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

`markdown
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

`markdown
[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][github-remark-gfm]).

`markdown
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

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

##### gfm-table.md

###### In

> 👉 Note: this example uses
> GFM ([remark-gfm][github-remark-gfm]).

`markdown
| [Planet] | [Radius] |
| ----------------- | --------- |
| [Mercury] | 2439.7 km |

[planet]: https://example.com/planet/
`

###### Out

`text
1:23-1:31: Unexpected reference to undefined definition, expected corresponding definition (radius) for a link or escaped opening bracket (\[) for regular text
3:3-3:12: Unexpected reference to undefined definition, expected corresponding definition (mercury) for a link or escaped opening bracket (\[) for regular text
`

##### allow-shortcut-link.md

When configured with { allowShortcutLink: true }.

###### In

`markdown
[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

`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
`

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][github-dotfiles-contributing] in [remarkjs/.github][github-dotfiles-health] for ways
to get started.
See [support.md`][github-dotfiles-support] for ways to get help.

This project has a [code of conduct][github-dotfiles-coc].
By interacting with this repository, organization, or community you agree to
abide by its terms.

License

[MIT][file-license] © [Titus Wormer][author]

[api-options]: #options

[api-remark-lint-no-undefined-references]: #unifieduseremarklintnoundefinedreferences-options

[author]: https://wooorm.com

[badge-build-image]: https://github.com/remarkjs/remark-lint/workflows/main/badge.svg

[badge-build-url]: https://github.com/remarkjs/remark-lint/actions

[badge-chat-image]: https://img.shields.io/badge/chat-discussions-success.svg

[badge-chat-url]: https://github.com/remarkjs/remark/discussions

[badge-coverage-image]: https://img.shields.io/codecov/c/github/remarkjs/remark-lint.svg

[badge-coverage-url]: https://codecov.io/github/remarkjs/remark-lint

[badge-downloads-image]: https://img.shields.io/npm/dm/remark-lint-no-undefined-references.svg

[badge-downloads-url]: https://www.npmjs.com/package/remark-lint-no-undefined-references

[badge-funding-backers-image]: https://opencollective.com/unified/backers/badge.svg

[badge-funding-sponsors-image]: https://opencollective.com/unified/sponsors/badge.svg

[badge-funding-url]: https://opencollective.com/unified

[badge-size-image]: https://img.shields.io/bundlejs/size/remark-lint-no-undefined-references

[badge-size-url]: https://bundlejs.com/?q=remark-lint-no-undefined-references

[esm-sh]: https://esm.sh

[file-license]: https://github.com/remarkjs/remark-lint/blob/main/license

[github-dotfiles-coc]: https://github.com/remarkjs/.github/blob/main/code-of-conduct.md

[github-dotfiles-contributing]: https://github.com/remarkjs/.github/blob/main/contributing.md

[github-dotfiles-health]: https://github.com/remarkjs/.github

[github-dotfiles-support]: https://github.com/remarkjs/.github/blob/main/support.md

[github-gist-esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[github-remark-gfm]: https://github.com/remarkjs/remark-gfm

[github-remark-lint]: https://github.com/remarkjs/remark-lint

[github-unified-transformer]: https://github.com/unifiedjs/unified#transformer

[npm-install]: https://docs.npmjs.com/cli/install

[typescript]: https://www.typescriptlang.org