remark-lint-no-duplicate-headings-in-section

remark-lint-no-duplicate-headings-in-section

remark-lint rule to warn when headings with the same text are used multiple times per section.

Contents

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

What is this?

This package is a unified (remark) plugin, specifically a remark-lint rule. Lint rules check markdown code style.

When should I use this?

You can use this package to check that headings with the same text are used once per section.

Presets

This rule is not included in a preset maintained here.

Install

This package is ESM only. In Node.js (version 12.20+, 14.14+, or 16.0+), install with npm:

npm install remark-lint-no-duplicate-headings-in-section

In Deno with Skypack:

import remarkLintNoDuplicateHeadingsInSection from 'https://cdn.skypack.dev/remark-lint-no-duplicate-headings-in-section@3?dts'

In browsers with Skypack:

<script type="module">
  import remarkLintNoDuplicateHeadingsInSection from 'https://cdn.skypack.dev/remark-lint-no-duplicate-headings-in-section@3?min'
</script>

Use

On the API:

import {read} from 'to-vfile'
import {reporter} from 'vfile-reporter'
import {remark} from 'remark'
import remarkLint from 'remark-lint'
import remarkLintNoDuplicateHeadingsInSection from 'remark-lint-no-duplicate-headings-in-section'

main()

async function main() {
  const file = await remark()
    .use(remarkLint)
    .use(remarkLintNoDuplicateHeadingsInSection)
    .process(await read('example.md'))

  console.error(reporter(file))
}

On the CLI:

remark --use remark-lint --use remark-lint-no-duplicate-headings-in-section example.md

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

 …
 "remarkConfig": {
   "plugins": [
     …
     "remark-lint",
+    "remark-lint-no-duplicate-headings-in-section",
     …
   ]
 }
 …

API

This package exports no identifiers. The default export is remarkLintNoDuplicateHeadingsInSection.

unified().use(remarkLintNoDuplicateHeadingsInSection[, config])

This rule supports standard configuration that all remark lint rules accept (such as false to turn it off or [1, options] to configure it).

There are no options.

Recommendation

It’s likely a mistake that the same heading text is used in the same section.

Examples

ok.md

In

## Alpha

### Bravo

## Charlie

### Bravo

### Delta

#### Bravo

#### Echo

##### Bravo

Out

No messages.

not-ok.md

In

## Foxtrot

### Golf

### Golf

Out

5:1-5:9: Do not use headings with similar content per section (3:1)

not-ok-tolerant-heading-increment.md

In

# Alpha

#### Bravo

###### Charlie

#### Bravo

###### Delta

Out

7:1-7:11: Do not use headings with similar content per section (3:1)

Compatibility

Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 12.20+, 14.14+, and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.

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