unified-lint-rule

What is unified-lint-rule?

The `unified-lint-rule` package is a utility for creating linting rules for unified processors. Unified is a project that provides a suite of tools for processing content, such as Markdown and HTML, in a structured way. The `unified-lint-rule` package allows developers to define custom linting rules that can be used to enforce coding standards, catch errors, and ensure consistency in content processing.

What are unified-lint-rule's main functionalities?

Creating a Custom Lint Rule

This feature allows you to create a custom linting rule. In this example, the rule checks for the presence of the word 'foo' in text nodes and reports a message if it is found.

const rule = require('unified-lint-rule');
const visit = require('unist-util-visit');

const noFoo = rule('example/no-foo', (tree, file) => {
  visit(tree, 'text', (node) => {
    if (node.value.includes('foo')) {
      file.message('Do not use the word "foo"', node);
    }
  });
});

module.exports = noFoo;

Integrating with Unified Processor

This feature demonstrates how to integrate a custom linting rule with a unified processor. The example shows how to use the `unified`, `remark-parse`, and `remark-lint` packages along with the custom `noFoo` rule to process a Markdown string and report any linting messages.

const unified = require('unified');
const markdown = require('remark-parse');
const lint = require('remark-lint');
const noFoo = require('./path-to-no-foo-rule');

unified()
  .use(markdown)
  .use(lint)
  .use(noFoo)
  .process('This is a foo test', (err, file) => {
    if (err) throw err;
    console.error(report(file));
  });

Other packages similar to unified-lint-rule

eslint

ESLint is a widely-used linting tool for JavaScript and TypeScript. It allows developers to define and enforce coding standards and catch errors in their code. Unlike `unified-lint-rule`, which is specific to content processing with unified, ESLint is focused on JavaScript code quality and style.

stylelint

Stylelint is a powerful linting tool for CSS and other style languages. It helps developers enforce consistent conventions and avoid errors in their stylesheets. While `unified-lint-rule` is used for content processing, Stylelint is specifically designed for linting styles.

remark-lint

Remark-lint is a collection of linting rules for Markdown files, built on top of the unified ecosystem. It provides a set of predefined rules for Markdown content, similar to how `unified-lint-rule` allows for custom rule creation. Remark-lint is more focused on Markdown-specific linting.

README

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

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

const remarkLintFileExtension = lintRule(
  'remark-lint:file-extension',
  (tree, file, option = 'md') => {
    var ext = file.extname

    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