remark-lint rule to warn on duplicate headings in a section
npm install remark-lint-no-duplicate-headings-in-section[![Build][badge-build-image]][badge-build-url]
[![Coverage][badge-coverage-image]][badge-coverage-url]
[![Downloads][badge-downloads-image]][badge-downloads-url]
[![Size][badge-size-image]][badge-size-url]
[![Sponsors][badge-funding-sponsors-image]][badge-funding-url]
[![Backers][badge-funding-backers-image]][badge-funding-url]
[![Chat][badge-chat-image]][badge-chat-url]
[remark-lint][github-remark-lint] rule to warn when the same text is used in multiple headings
in a section.
* What is this?
* When should I use this?
* Presets
* Install
* Use
* API
* unified().use(remarkLintNoDuplicateHeadingsInSection)
* Recommendation
* Examples
* Compatibility
* Contribute
* License
This package checks that headings are unique in sections.
You can use this package to check that headings are unique.
This plugin is not included in presets maintained here.
This package is [ESM only][github-gist-esm].
In Node.js (version 16+),
install with [npm][npm-install]:
``sh`
npm install remark-lint-no-duplicate-headings-in-section
In Deno with [esm.sh][esm-sh]:
`js`
import remarkLintNoDuplicateHeadingsInSection from 'https://esm.sh/remark-lint-no-duplicate-headings-in-section@4'
In browsers with [esm.sh][esm-sh]:
`html`
On the API:
`js
import remarkLint from 'remark-lint'
import remarkLintNoDuplicateHeadingsInSection from 'remark-lint-no-duplicate-headings-in-section'
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(remarkLintNoDuplicateHeadingsInSection)
.use(remarkStringify)
.process(file)
console.error(reporter(file))
`
On the CLI:
`sh`
remark --frail --use remark-lint --use remark-lint-no-duplicate-headings-in-section .
On the CLI in a config file (here a package.json):
`diff`
…
"remarkConfig": {
"plugins": [
…
"remark-lint",
+ "remark-lint-no-duplicate-headings-in-section",
…
]
}
…
This package exports no identifiers.
It exports no additional [TypeScript][typescript] types.
The default export is
[remarkLintNoDuplicateHeadingsInSection][api-remark-lint-no-duplicate-headings-in-section].
Warn when the same text is used in multiple headings in a section.
###### Parameters
There are no options.
###### Returns
Transform ([Transformer from unified][github-unified-transformer]).
It’s likely a mistake that the same heading text is used in the same
section.
##### ok.md
###### In
`markdownPlanets
#### Discovery
`
###### Out
No messages.
##### not-ok.md
###### In
`markdownPlanets
###### Out
text
7:1-7:14: Unexpected heading with equivalent text in section, expected unique headings
`#####
###### In
markdown
Planets
#### Discovery
###### Phobos
#### Discovery
###### Deimos
`###### Out
text
7:1-7:15: Unexpected heading with equivalent text in section, expected unique headings
`#####
###### In
> 👉 Note: this example uses
> MDX ([
][github-remark-mdx]).`mdx
MDX is supported too.Planets
Mars
Discovery
Discovery
`###### Out
text
6:1-6:19: Unexpected heading with equivalent text in section, expected unique headings
`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,
,
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.
[MIT][file-license] © [Titus Wormer][author]
[api-remark-lint-no-duplicate-headings-in-section]: #unifieduseremarklintnoduplicateheadingsinsection
[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-duplicate-headings-in-section.svg
[badge-downloads-url]: https://www.npmjs.com/package/remark-lint-no-duplicate-headings-in-section
[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-duplicate-headings-in-section
[badge-size-url]: https://bundlejs.com/?q=remark-lint-no-duplicate-headings-in-section
[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-lint]: https://github.com/remarkjs/remark-lint
[github-remark-mdx]: https://mdxjs.com/packages/remark-mdx/
[github-unified-transformer]: https://github.com/unifiedjs/unified#transformer
[npm-install]: https://docs.npmjs.com/cli/install
[typescript]: https://www.typescriptlang.org