remark-lint-file-extension

remark-lint rule to warn for unexpected file extensions.

Contents

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

What is this?

This package checks the file extension.

When should I use this?

You can use this package to check that file extensions are consistent.

Presets

This plugin is included in the following presets:

Install

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

npm install remark-lint-file-extension

In Deno with esm.sh:

import remarkLintFileExtension from 'https://esm.sh/remark-lint-file-extension@3'

In browsers with esm.sh:

Use

On the API:

import remarkLint from 'remark-lint'
import remarkLintFileExtension from 'remark-lint-file-extension'
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(remarkLintFileExtension)
  .use(remarkStringify)
  .process(file)

console.error(reporter(file))

On the CLI:

remark --frail --use remark-lint --use remark-lint-file-extension .

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

 …
 "remarkConfig": {
   "plugins": [
     …
     "remark-lint",
+    "remark-lint-file-extension",
     …
   ]
 }
 …

API

This package exports no identifiers. It exports the TypeScript types Extensions and Options. The default export is remarkLintFileExtension.

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

Warn for unexpected extensions.

Parameters

• options (Extensions or Options, optional) — configuration

Returns

Transform (Transformer from unified).

Extensions

File extension(s) (TypeScript type).

Type

type Extensions = Array | string

Options

Configuration (TypeScript type).

Fields

• allowExtensionless (boolean, default: true) — allow no file extension such as AUTHORS or LICENSE
• extensions (Extensions, default: ['mdx', 'md']) — allowed file extension(s)

Recommendation

Use md as it’s the most common. Also use md when your markdown contains common syntax extensions (such as GFM, frontmatter, or math). Do not use md for MDX: use mdx instead.

Examples

readme.md

Out

No messages.

readme.mdx

Out

No messages.

readme

Out

No messages.

readme

When configured with { allowExtensionless: false }.

Out

1:1: Unexpected missing file extension, expected `mdx` or `md`

readme.mkd

Out

1:1: Unexpected file extension `mkd`, expected `mdx` or `md`

readme.mkd

When configured with 'mkd'.

Out

No messages.

readme.css

When configured with [ 'markdown', 'md', 'mdown', 'mdwn', 'mdx', 'mkd', 'mkdn', 'mkdown', 'ron' ].

Out

1:1: Unexpected file extension `css`, expected `markdown`, `md`, `mdown`, …

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-file-extension@3, 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