A Node.js style checker and lint tool for Markdown/CommonMark files.
Markdownlint is a Node.js style checker and lint tool for Markdown and CommonMark files. It uses the micromark parser and supports CommonMark as well as GitHub Flavored Markdown extensions like autolinks, tables, directives, footnotes, and math syntax. The project includes a library of over 60 built-in validation rules to enforce Markdown formatting standards and consistency, and also exposes helper functions for developers to create custom rules. The tool is inspired by Mark Harrison's markdownlint for Ruby and provides asynchronous, synchronous, and Promise-based APIs for linting files.