unified-lint-rule

unified plugin to help make lint rules.

See the monorepo readme for more info on remark lint.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • lintRule(origin|meta, rule)
• Compatibility
• Contribute
• License

What is this?

This package is a unified plugin that makes it a bit easier to create linting rules.

unified is a project that transforms content with abstract syntax trees (ASTs). This is a plugin that make it easier to inspect trees.

When should I use this?

You can use this package when you want to make custom lint rules.

Install

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

npm install unified-lint-rule

In Deno with esm.sh:

import {lintRule} from 'https://esm.sh/unified-lint-rule@2'

In browsers with esm.sh:

<script type="module">
  import {lintRule} from 'https://esm.sh/unified-lint-rule@2?bundle'
</script>

Use

/**
 * @typedef {import('mdast').Root} Root
 */

/**
 * @typedef {string} Options
 *   Configuration.
 */

import {lintRule} from 'unified-lint-rule'

const remarkLintFileExtension = lintRule(
  'remark-lint:file-extension',
  /**
   * @param {Root} tree
   *   Tree.
   * @param {Options | null | undefined} options
   *   Configuration (default: `'md'`).
   */
  function (tree, file, options) {
    const ext = file.extname
    const option = options || 'md'

    if (ext && ext.slice(1) !== option) {
      file.message('Incorrect extension: use `' + option + '`')
    }
  }
)

export default remarkLintFileExtension

API

This package exports the following identifier: lintRule. There is no default export.

lintRule(origin|meta, rule)

Create a plugin.

Parameters

• origin (string) — treated as a meta of {origin}
• meta (Object) — rule metadata
• meta.origin (string) — message origin, either a rule name ('file-extension') or both a rule source and name joined with : ('remark-lint:file-extension')
• meta.url (string, optional) — URL to documentation for messages
• rule (Function, optional) — your code, like a transform function, except that an extra option is passed

Returns

A unified plugin that handles all kinds of options (see Configure in the monorepo readme for how them).

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