eslint-plugin-markdown-preferences

eslint-plugin-markdown-preferences

A specialized ESLint plugin that helps enforce consistent writing style and formatting conventions in Markdown files. Perfect for documentation projects, blog posts, and any Markdown content where consistency matters.

📛 Features

• 📝 Comprehensive style enforcement Enforces consistent heading casing, table header casing, inline code/link usage, emoji notation, and more for unified document style.
• 🧩 Powerful formatting consistency Strongly standardizes Markdown formatting: whitespace, indentation, spacing, line breaks, list markers, code fences, links, references, thematic breaks, tables, and decorative elements—ensuring documents are clean and uniform.
• 🚀 Extended Markdown syntax support Supports custom containers, mathematical expressions, and other extended syntax for high compatibility with VitePress.
• 🔧 Auto-fix support Most rules support ESLint's --fix option for automatic correction.
• 🌐 Online Demo & Documentation Try it instantly in the Online Demo and see full documentation.

📖 Documentation

For detailed usage instructions, rule configurations, and examples, visit our comprehensive documentation site.

💿 Installation

npm install --save-dev eslint @eslint/markdown eslint-plugin-markdown-preferences

📖 Usage

Configuration

New Config (eslint.config.js)

Use eslint.config.js file to configure rules. See also: https://eslint.org/docs/latest/use/configure/configuration-files-new.

Example eslint.config.js:

import { defineConfig } from "eslint/config";
// import markdown from "@eslint/markdown";
import markdownPreferences from "eslint-plugin-markdown-preferences";
export default defineConfig([
  // add more generic rule sets here, such as:
  // markdown.configs.recommended,
  markdownPreferences.configs.recommended,
  {
    files: ["**/*.md", "*.md"],
    rules: {
      // override/add rules settings here, such as:
      // 'markdown-preferences/prefer-linked-words': 'error'
    },
  },
]);

This plugin provides configs:

• *.configs.recommended ... Recommended config provided by the plugin.
• *.configs.standard ... Enforces opinionated stylistic conventions. You can extend this to enforce any stylistic conventions you like.

See the rule list to get the rules that this plugin provides.

Using Extended Syntax

This plugin experimentally supports some extended Markdown syntax.
To use these extended syntaxes, set the markdown-preferences/extended-syntax language option.

import { defineConfig } from "eslint/config";
import markdownPreferences from "eslint-plugin-markdown-preferences";
export default defineConfig([
  {
    extends: [markdownPreferences.configs.recommended],
    language: "markdown-preferences/extended-syntax",
  },
]);

The following syntaxes are supported:

• Custom Containers
  Example:

  ::: warning
  This is a warning box.
  :::
  

• Mathematical Expressions
  Example:

  $$
  E = mc^2
  $$
  

• VitePress-style Import Code Snippets syntax using triple left angle brackets
  Example:

  <<< @/filepath
  

Legacy Config (.eslintrc)

Is not supported.

✅ Rules

The --fix option on the command line automatically fixes problems reported by rules which have a wrench 🔧 below.
The rules with the following ⭐ are included in the recommended config.
The rules with the following 💄 are included in the standard config.

Preference Rules

• Rules to unify the expression and description style of documents.

Rule ID	Description	Fixable	Config
markdown-preferences/canonical-code-block-language	enforce canonical language names in code blocks	🔧
markdown-preferences/emoji-notation	enforce consistent emoji notation style in Markdown files.	🔧
markdown-preferences/heading-casing	enforce consistent casing in headings.	🔧
markdown-preferences/no-heading-trailing-punctuation	disallow trailing punctuation in headings.
markdown-preferences/ordered-list-marker-start	enforce that ordered list markers start with 1 or 0	🔧	💄
markdown-preferences/prefer-inline-code-words	enforce the use of inline code for specific words.	🔧
markdown-preferences/prefer-linked-words	enforce the specified word to be a link.	🔧
markdown-preferences/table-header-casing	enforce consistent casing in table header cells.	🔧

Notation Rules

• Rules related to notation styles in Markdown.

Rule ID	Description	Fixable	Config
markdown-preferences/bullet-list-marker-style	enforce consistent bullet list (unordered list) marker style	🔧	💄
markdown-preferences/code-fence-style	enforce a consistent code fence style (backtick or tilde) in Markdown fenced code blocks.	🔧	💄
markdown-preferences/definitions-last	require link definitions and footnote definitions to be placed at the end of the document	🔧
markdown-preferences/emphasis-delimiters-style	enforce a consistent delimiter style for emphasis and strong emphasis	🔧	💄
markdown-preferences/hard-linebreak-style	enforce consistent hard linebreak style.	🔧	⭐💄
markdown-preferences/level1-heading-style	enforce consistent style for level 1 headings	🔧	💄
markdown-preferences/level2-heading-style	enforce consistent style for level 2 headings	🔧	💄
markdown-preferences/link-destination-style	enforce a consistent style for link destinations	🔧	💄
markdown-preferences/link-title-style	enforce a consistent style for link titles	🔧	💄
markdown-preferences/no-implicit-block-closing	disallow implicit block closing for fenced code blocks, math blocks, and custom containers	🔧	⭐💄
markdown-preferences/no-text-backslash-linebreak	disallow text backslash at the end of a line.		⭐💄
markdown-preferences/ordered-list-marker-style	enforce consistent ordered list marker style	🔧	💄
markdown-preferences/prefer-autolinks	enforce the use of autolinks for URLs	🔧	⭐💄
markdown-preferences/prefer-fenced-code-blocks	enforce the use of fenced code blocks over indented code blocks	🔧	⭐💄
markdown-preferences/prefer-link-reference-definitions	enforce using link reference definitions instead of inline links	🔧
markdown-preferences/strikethrough-delimiters-style	enforce a consistent delimiter style for strikethrough	🔧	💄
markdown-preferences/thematic-break-character-style	enforce consistent character style for thematic breaks (horizontal rules) in Markdown.	🔧	💄

Whitespace Rules

• Rules related to whitespace styles in Markdown.

Rule ID	Description	Fixable	Config
markdown-preferences/blockquote-marker-alignment	enforce consistent alignment of blockquote markers	🔧	⭐💄
markdown-preferences/code-fence-spacing	require or disallow spacing between opening code fence and language identifier	🔧	💄
markdown-preferences/custom-container-marker-spacing	require or disallow spacing between opening custom container marker and info	🔧	💄
markdown-preferences/indent	enforce consistent indentation in Markdown files	🔧	💄
markdown-preferences/link-bracket-newline	enforce linebreaks after opening and before closing link brackets	🔧	💄
markdown-preferences/link-bracket-spacing	enforce consistent spacing inside link brackets	🔧	💄
markdown-preferences/link-paren-newline	enforce linebreaks after opening and before closing link parentheses	🔧	💄
markdown-preferences/link-paren-spacing	enforce consistent spacing inside link parentheses	🔧	💄
markdown-preferences/list-marker-alignment	enforce consistent alignment of list markers	🔧	⭐💄
markdown-preferences/no-multi-spaces	disallow multiple spaces	🔧	💄
markdown-preferences/no-multiple-empty-lines	disallow multiple empty lines in Markdown files.	🔧	💄
markdown-preferences/no-tabs	disallow tab characters in Markdown files.	🔧	💄
markdown-preferences/no-trailing-spaces	disallow trailing whitespace at the end of lines in Markdown files.	🔧	💄
markdown-preferences/padded-custom-containers	disallow or require padding inside custom containers	🔧	💄
markdown-preferences/padding-line-between-blocks	require or disallow padding lines between blocks	🔧	💄
markdown-preferences/table-pipe-spacing	enforce consistent spacing around table pipes	🔧	💄

Decorative Rules

• Rules related to visual or stylistic decorations in Markdown.

Rule ID	Description	Fixable	Config
markdown-preferences/atx-heading-closing-sequence-length	enforce consistent length for the closing sequence (trailing #s) in ATX headings.	🔧	💄
markdown-preferences/atx-heading-closing-sequence	enforce consistent use of closing sequence in ATX headings.	🔧	💄
markdown-preferences/code-fence-length	enforce consistent code fence length in fenced code blocks.	🔧	💄
markdown-preferences/max-len	enforce maximum length for various Markdown entities
markdown-preferences/no-laziness-blockquotes	disallow laziness in blockquotes		⭐💄
markdown-preferences/ordered-list-marker-sequence	enforce consistent ordered list marker numbering (sequential or flat)	🔧	💄
markdown-preferences/setext-heading-underline-length	enforce setext heading underline length	🔧	💄
markdown-preferences/sort-definitions	enforce a specific order for link definitions and footnote definitions	🔧	💄
markdown-preferences/table-leading-trailing-pipes	enforce consistent use of leading and trailing pipes in tables.	🔧	💄
markdown-preferences/table-pipe-alignment	enforce consistent alignment of table pipes	🔧	💄
markdown-preferences/thematic-break-length	enforce consistent length for thematic breaks (horizontal rules) in Markdown.	🔧	💄
markdown-preferences/thematic-break-sequence-pattern	enforce consistent repeating patterns for thematic breaks (horizontal rules) in Markdown.	🔧	💄

👫 Related Packages

• eslint-plugin-markdown-links ... ESLint plugin with powerful checking rules related to Markdown links.

🍻 Contributing

Welcome contributing!

Please use GitHub's Issues/PRs.

Development Tools

• npm test runs tests and measures coverage.
• npm run update runs in order to update readme and recommended configuration.

🔒 License

See the LICENSE file for license rights and limitations (MIT).