unified

Project: remarkjs/remark-lint

Package: remark-lint-no-multiple-toplevel-headings@3.1.1

  1. Dependents: 0
  2. remark-lint rule to warn when multiple top level headings are used
  1. remark 214
  2. lint 80
  3. rule 75
  4. remark-lint-rule 68
  5. heading 26

remark-lint-no-multiple-toplevel-headings

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remark-lint rule to warn when multiple top-level headings are used.

Contents

What is this?

This package checks that no more than one top level heading is used.

When should I use this?

You can use this package to check heading structure.

Presets

This plugin is included in the following presets:

PresetOptions
remark-preset-lint-markdown-style-guide

Install

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

npm install remark-lint-no-multiple-toplevel-headings

In Deno with esm.sh:

import remarkLintNoMultipleToplevelHeadings from 'https://esm.sh/remark-lint-no-multiple-toplevel-headings@3'

In browsers with esm.sh:

<script type="module">
  import remarkLintNoMultipleToplevelHeadings from 'https://esm.sh/remark-lint-no-multiple-toplevel-headings@3?bundle'
</script>

Use

On the API:

import remarkLint from 'remark-lint'
import remarkLintNoMultipleToplevelHeadings from 'remark-lint-no-multiple-toplevel-headings'
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(remarkLintNoMultipleToplevelHeadings)
  .use(remarkStringify)
  .process(file)

console.error(reporter(file))

On the CLI:

remark --frail --use remark-lint --use remark-lint-no-multiple-toplevel-headings .

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

 …
 "remarkConfig": {
   "plugins": [
     …
     "remark-lint",
+    "remark-lint-no-multiple-toplevel-headings",
     …
   ]
 }
 …

API

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

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

Warn when multiple top-level headings are used.

Parameters
Returns

Transform (Transformer from unified).

Options

Configuration (TypeScript type).

Type
type Options = 1 | 2 | 3 | 4 | 5 | 6

Recommendation

Documents should almost always have one main heading, which is typically a heading with a rank of 1.

Examples

ok.md

When configured with 1.

In
# Foo

## Bar
Out

No messages.

not-ok.md

When configured with 1.

In
# Foo

# Bar
Out
3:1-3:6: Don’t use multiple top level headings (1:1)

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-multiple-toplevel-headings@3, compatible with Node.js 12.

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